Key to food security and nutrition in Africa SUSTAINABLE SOIL MANAGEMENT: ISSN 2026-5611

Key to food security and nutrition in Africa SUSTAINABLE SOIL MANAGEMENT: ISSN 2026-5611
ISSN 2026-5611
SUSTAINABLE SOIL MANAGEMENT:
Key to food security
and nutrition in Africa
Photo Credits
Photo Credit: @ FAO
Photo Credit: @FAO/Rosetta Messori
Photo Credit: @FAO/Giulio Napolitano
Photo Credit: Dana Baker
Photo Credit: Katrien Holvoet
Photo Credit: David Young
Photo Credit: Isaurinda Baptista
Photo Credit: Addam Kiari Saidou
Photo Credit: Edson Gandiwa
Photo Credit: Gerhard Nortjé
Nature & Faune
Enhancing natural resources management for food security in Africa
Volume 30, Issue 1
Sustainable Soil Management:
Key to Food Security and Nutrition in Africa
Editor: Foday Bojang
Deputy Editor: Ada Ndeso-Atanga
FAO Regional Office for Africa
[email protected]
http://www.fao.org/africa/resources/nature-faune/en/
Regional Office for Africa
FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
Accra, 2015
BOARD OF REVIEWERS
Christel Palmberg-Lerche
Forest geneticist
Rome, Italy
Mafa Chipeta
Food security adviser
Limbe, Malawi
Kay Muir-Leresche
Policy economist/specialist in agricultural and natural resource economics
Rooiels Cape, South Africa
Jeffrey Sayer
Ecologist/expert in political and economic context of natural resources conservation
Cairns, N. Queensland, Australia
Sébastien Le Bel
Wildlife specialist and scientist
Montpellier, France
Fred Kafeero
Natural resources specialist
Rome, Italy
August Temu
Agroforestry and forestry education expert
Arusha, Tanzania
Jean Prosper Koyo
Renewable natural resources adviser
Pointe Noire, Republic of Congo
Douglas Williamson
Wildlife specialist
England, United Kingdom
El Hadji M. Sène
Forest resources management & dry zone forestry specialist
Dakar, Senegal
Ousmane Guindo
Specialist in agricultural trade & marketing policies and natural resource management
Asmara, Eritrea
Advisers: Atse Yapi, Christopher Nugent, Fernando Salinas, René Czudek
AD HOC INDEPENDENT EXTERNAL REVIEW COMMITTEE
Special edition of Nature & Faune journal for 2015 International Year of Soils
Michiel C. Laker
Emeritus-Professor of Soil Science
Pretoria, South Africa
Victor O. Chude
Soil scientist
Abuja, Nigeria
Patrick Gicheru
Soil scientist
Embu, Kenya
Michel Sedogo
Soil scientist
Ouagadougou, Burkina Faso
Botle Esther MAPESHOANE
Soil scientist
Maseru, Lesotho
Bhanooduth Lalljee
Soil Scientist
Port Louis, Mauritius
Nature & Faune Volume 30, Issue No. 1
iii
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not mentioned.
ISSN 2026-5611
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Nature & Faune Volume 30, Issue No. 1
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CONTENTS
MESSAGE TO READERS
Bukar Tijani
1
EDITORIAL
Michiel C. Laker
3
SPECIAL FEATURE
Tailoring soil fertility management inputs to specific soil types:
case study of a pot experiment in Rwanda
7
Pascal N. Rushemuka and Laurent Bock
OPINION PIECE
The living soils of Africa
13
Lamourdia Thiombiano
ARTICLES
Towards a sustainable soil security in sub-Saharan Africa:
some challenges and management options
Akim O. Osunde
15
Priorities for sustainable soil management in Nigeria
Victor Okechukwu Chude and Azubuike Chidowe Odunze
18
National priorities for sustainable soil management in Gambia
Abdou Rahman Jobe
22
Priorities for sustainable soil management in Ghana
Francis M. Tetteh and Enoch Boateng
24
Strategies towards sustainable soil management in
Cabo Verde: environmental and livelihood challenges
Isaurinda Baptista
130
26
Sustainable soil management in Niger : constraints,
challenges, opportunities and priorities
Addam Kiari Saidou and Aboubacar Ichaou
130
30
Can Nigerian soils sustain crop production? The dilemma of a soil scientist
Fasina A. Sunday , Oluwadare D. Abiodun , Omoju O. Johnson , Oluleye A.
Kehinde , Ogbonnaya U. Ogbonnaya, and Ogunleye K. Samuel
Siltation of major rivers in Gonarezhou National Park,
Zimbabwe: a conservation perspective
Edson Gandiwa and Patience Zisadza-Gandiwa
Comparative study of the production of maize cultivars that
are tolerant of low-nitrogen soils, with and without fertiliser
in the Democratic Republic of Congo
Jean Pierre Kabongo Tshiabukole*, Pongi Khonde, Kankolongo Mbuya,
Jadika Tshimbombo, Kasongo Kaboko, Badibanga Mulumba, Kasongo
Tshibanda and Muliele Muku
Effect of no-tillage with mulching on yield of East African
highlands banana intercropped with beans at Mulungu, in
the Eastern Democratic Republic of Congo.
Tony Muliele Muku
130
34
130
39
130
43
130
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Nature & Faune Volume 30, Issue No. 1
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CONTENTS
Agro-economic efficiency of mineral and organic fertilization of
beans on the ultisols of the highlands of eastern Democratic
Republic of the Congo
Audry Muke Manzekele, Lunze Lubanga, Telesphore Mirindi, Benjamin
Wimba, Katcho Karume, Solange Kaz, Sospeter Nyamwaro, Moses
Tenywa, Josaphat Mugabo, Robin Buruchara, Oluwole Fatunbi, and
Adewale Adekunle
49
Physico-chemical properties of soils under oil palm plantations of
different ages
Sebastian Wisdom Brahene, Emmanuel Owusu-Bennoah, and Mark K. Abekoe
54
Utilization of aerobically composted wood waste and chicken
manure as organic fertilizer
Stephen Okhumata Dania , Lucy Eiremonkhale , and Margaret Iyabode Dania
59
Soil erodibility evaluation in Makurdi Benue State, Nigeria
Blessing Iveren Agada and Martins Eze Obi
62
Role of soil in nutrition sensitive food systems in Africa
Mawuli Sablah, Mohamed AgBendech, Lamourdia Thiombiano, and
Laouratou Dia
65
The Importance of sustainable land management for food security
and healthy human nutrition in Central Africa
Ousseynou Ndoye
68
Human impacts on sustainable soil management in game parks:
Findings based on research in the Kruger National Park, South Africa,
and reconnaissance studies in the Serengeti National Park, Tanzania
Gerhard Nortjé
A meta- analysis of climate change mitigation potential of
trees/forest, afforestation and woody perennials through soil carbon
sequestration in Africa
Oladele O. Idowu and Ademola K. Braimoh
Sustaining soil natural capital through climate-smart farmland
management
Ernest L. Molua, Marian S. delos Angeles and Jonas Mbwangue
Agricultural intensification by small-scale farmers in hydromorphic
wetlands as a tool to counteract climate change effects: a case study
in Xai -Xai district in Mozambique
Paulo Chaguala and Laurinda Nobela
Soil fertility and climate benefits of conservation agriculture
adoption, in the highlands of Tanzania
Janie Rioux and Marta Gomez San Juan
Observations from the field: Impacts of conservation programming
on community livelihood strategies and local governance structures
in the Eastern Arc Mountain Range, Tanzania
Dana M. Baker
Analysis of sustainable livelihoods diversification of marine fishing
communities in Benin
Katrien Holvoet , Denis Gnakpenou , and Rita Agboh Noameshie
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85
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90
130
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Nature & Faune Volume 30, Issue No. 1
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CONTENTS
COUNTRY FOCUS: REPUBLIC OF CABO VERDE
Jacques de Pina Tavares
103
FAO ACTIVITIES AND RESULTS
Key messages on soils from the Forestry Department of Food and
Agriculture Organization of the United Nations
108
Promoting sustainable soil management in sub-Saharan Africa through the
African Soil Partnership
Liesl Wiese, Craig Chibanda, Victor Chude, Ronald Vargas, and Lucrezia Caon
109
LINKS
112
NEWS
113
ANNOUNCEMENTS
115
THEME AND DEADLINE FOR NEXT ISSUE
117
GUIDELINES FOR AUTHORS, SUBSCRIPTION AND
CORRESPONDENCE
118
Nature & Faune Volume 30, Issue No. 1
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Rows of trees planted along the banks of irrigation and drainage canals in the city of Luxor, Egypt.
Photo Credit: @FAO/Rosetta Messori
Nature & Faune Volume 30, Issue No. 1
viii
MESSAGE TO READERS
MESSAGE TO READERS
Bukar Tijani1
The United Nations declared 2015 as the International Year of
Soils. As a contribution to marking this event of global
importance, this special issue of Nature & Faune journal
addresses the central theme “Sustainable soil management: a
key to food security and nutrition in Africa”.
The quality of Africa's soils
Africa is said to have wonderful natural agricultural resources
which can enable it to “feed the world”. This potential needs to
be pursued and solutions sought to overcome obstacles to
making it a reality. Extensive areas of Africa are arid and semiarid, with low and erratic average rainfall, low biomass
production and consequently low organic matter content of
the soils. This is however balanced out in the humid tropical
areas of central and eastern Africa where the rainfall and soil
fertility is high.
Africa has very rich alluvial soils along most of its rivers. With
appropriate irrigation the potentials of these areas, e.g. in – the
mountains of central/east Africa, (Rwanda, Burundi, Uganda
etc.) and vast areas of Zimbabwe and Democratic Republic of
Congo, which are endowed with excellent agricultural soils,
can be maximally exploited. This edition encourages
development to favour agriculture in these high potential
areas. The lower potential soils often have capacities to grow
tree crops such as rubber, oil palm, cocoa etc.
This special issue of the journal contains about 30 papers from
various African countries, providing thus a panorama of
insights into the challenges to sustainable soil management
in Africa. Some of the papers are general review articles; others
are reports on results of specific experiments or surveys.
Readers are encouraged to read these papers with an open
mind and readiness to appreciate the great diversity of soil
resources in this large continent, a situation presenting
greater challenges which make the task of the soil scientist
more complex but thrilling.
The importance of soil surveys and assessments
The articles acknowledge that detailed soil surveys are
expensive and time consuming but are indispensable for
sustainable land use. They also indicate that opportunity
costs in terms of yield and crop loss if soil survey information is
lacking far outweigh the cost of undertaking the surveys. The
essays further indicate that Africa has beautiful broad scale
agro-ecological zone and soil maps, but that these are not
suitable for location-specific cropping and management
planning.
In order to undertake detailed soil survey and related work,
including research, strong, well manned and equipped soil
institutions (which are currently lacking in most countries) are
needed. A few papers also make strong pleas for the
development of local national soil classification systems,
despite existence of major international systems such as the
Soil Taxonomy and World Reference Base for soil resources
(WRB). The latter are believed to be good for international
communication on soils but not effective for local
interpretation and decision making on land use and planning
or sustainable soil management. A paper from Rwanda
highlights the existence of local soil classification systems at
community level. Local communities give names to different
soils that they distinguish and have effective land suitability
evaluation systems based on their soil classification; from
experience they know what can be done on which soil. For
example, farmers know that different soils need to be fertilized
differently.
Soil fertility management
Several papers deal with various aspects of soil fertility
management, especially in the highly weathered soils of the
humid tropical areas where almost all plant nutrients are
2
contained in the vegetation (ISSS Working Group RB, 1998 ).
Long term slash and burn and fallow practices have
contributed to the fertility status of soils in areas where this is
practiced. Due to population pressures, fallow periods have
drastically reduced, resulting in a non-sustainable system.. An
experiment described by a paper from Nigeria shows that
when plant material was burned and the ash was left on the
soil, or where unburned plant residues were incorporated into
the soil, second year yield drop was far less than when plant
residues were baled and removed – in which case second
year yield dropped by 45%.
Minimising risk, including from climate change
There are various technologies which small scale farmers in
Africa use to minimize risks and cope with adverse soil and/or
climatic conditions. Examples discussed in the articles
include selection of appropriate cultivars that are adapted to
specific unfavourable or stress conditions. One paper from
Democratic Republic of Congo studied the selection of maize
cultivars for genetic traits that confer adaptation to low
nitrogen conditions. An inspirational paper from Niger
describes the successful implementation of indigenous soil
and water techniques at community level. Two papers from
Cabo Verde report how the dedication of successive
governments to the cause of soil and water conservation has
resulted in astonishing increases in yields of fruits and
vegetables in this Small Island State.
1
Bukar Tijani. Assistant Director-General
Regional Representative for Africa, Regional Office for Africa,
United Nations Food and Agriculture Organization,
P. O. Box GP 1628 Accra. Ghana.
Tel: (233) 302 675000 ext. 2101/ (233) 302 610 930;
Fax: 233 302 668 427
Email: [email protected]
2
The International Union of Soil Sciences (IUSS) Working Group RB
1998. World Reference Base for Soil Resources: Atlas (E.M. Bridges, N.H.
Batjes and F.O. Nachtergaele, Eds.). ISRIC-FAO-IUSS-Acco, Leuven.
Nature & Faune Volume 30, Issue No. 1
1
Contributors from Mozambique share the experiences of
farmers taking steps to reduce their vulnerability, adapt and
mitigate or reduce Green House Gases (GHG) emissions and
enhance GHG sinks. Farmers decided to abandon rainfed
cropping and shifted their whole attention to crop production
in the seasonally flooded wetlands along a major river. Such
cultivation during non-flood season is practised widely along
big rivers in Africa. Abilities of different systems to sequester
carbon and minimize greenhouse gas emissions also
received attention.
The human factor is key
Human factor in sustainable soil management is of
importance as reflected in two articles from Tanzania and one
from South Africa. The articles demonstrate the importance of
understanding the needs and priorities of farmers and
communities and how decisions are taken. Authors
demonstrate that it is only by attending to the needs and
aspirations of the people that the environment can be saved.
This is demonstrated in one case where the conflict between
a community and a protected forest area was resolved by
establishing an irrigation scheme for the community next to
the protected area. In another case it was found that farmers
opted not to adopt a conservation agriculture package, but
only selected components from the package, with very good
reasons. This corresponds with an emerging fact that whereas
scientists see a complete recommended package, farmers
see the individual components of the package and choose
individually. One human factor for success that is key is
working together. The African Soil Partnership has ambitious
plans to this effect as explained in an article featured under
FAO activities and results section.
The country under focus in this edition is the Republic of Cabo
Verde. A rural development researcher at the National Institute
for Agrarian Research and Development (INIDA), Jacques de
Pina Tavares, gives us a flavour of how watershed
management technologies have been designed to boost the
resilience of Cabo Verde to climate change, and to mitigate
the effects of desertification.
We believe this special issue of Nature & Faune journal, with its
exciting variety of papers dealing with issues related to
sustainable soil management in Africa is an important
contribution towards promoting sustainability on the
continent. As we conclude the 2015 International Year of Soils
and begin the 2016 International Year of the Pulses we believe
that the Africa region will take on the knowledge generated
and awareness raised and consolidate it during the
deliberations at the 7th Conference of the African Soil Science
Society taking place in Burkina Faso in February 2016; and at
an Inter-ministerial Conference to be organized later in 2016
to review progress made on the Abuja Fertilizer Convention setting a new timeline for implementation and strengthening
its implementation from fertilizer focus towards integrated soil
th
fertility management. There is also the 20 session of African
Forest and Wildlife Commission in Kenya (February 2016);
and the 29th Africa Regional Conference in Côte d'Ivoire (April
2016). These upcoming conferences and high level
engagements will build on steps already taken to inspire hope
and provide solutions to Africa's development challenges,
including the disquieting soil and soil-related challenges. I
hope that the African citizenry can count on you to face up to
these challenges!
Nature & Faune Volume 30, Issue No. 1
2
EDITORIAL
Understanding sustainable soil management in Africa
Michiel C. Laker1
The 2013 Soil Atlas of Africa (Jones, A. et al 2013) makes it
clear that only approximately 8% of the continent is covered by
soils that “are relatively free of natural constraints for
agriculture”, and that much of the presently cultivated land in
Africa “occurs on areas that are deemed unsuitable . . . while
other areas appear suitable but are not cultivated.” The Atlas
also reports that “Africa's climate has made agricultural
improvement difficult”. Many of Africa's soils have limitations
for crop production, some very severe, and they require
careful management if they are to be used sustainably. The
Atlas includes a global soil map, which “clearly shows that
Africa has a unique pattern of soils that is not replicated on the
other continents” (Jones et al., 2013). A striking feature is the
almost complete absence in Africa of the deep, inherently
fertile, organic matter rich, friable (and thus easy to cultivate)
soils that cover large areas of the temperate countries at high
latitudes in the northern hemisphere. These include the
Chernozems, Kastanozems and Phaeozems of the American
prairies and the Russian steppe. It is difficult to maintain
relatively high soil organic matter levels under the high
temperatures of Africa. A major proportion of the good soils
are black or red clayey soils that are difficult to cultivate. They
cannot be successfully managed using technologies and
management regimes that are successfully used in the
temperate countries without making appropriate adaptations
to these. In many cases completely new approaches are
required to enhance soil fertility, productivity and
sustainability.
Soil scientists in Africa are thus faced with three major
challenges, namely (i) to ensure that all areas covered by good
soils are utilized to their full potential, (ii) to find appropriate
adaptations to existing technologies to improve soil
management and production and (iii) to develop new
technologies for sustainable management – especially of the
extensive areas of marginal soil that farmers are obliged to
crop to achieve food security and adequate nutrition in Africa.
African farmers also face a range of political, socio-economic
and socio-cultural constraints. Poor infrastructure in terms of
roads and transport services is a major factor, limiting access
to inputs and delivering of produce to markets, especially for
small scale commercial farmers in remote rural areas. Often
the required inputs are not available in an area, or even in a
country. Where it is available, the input, e.g. fertilizer, is often
extremely expensive. Advisory services are often limited –
both in accessibility and in relevance to the small farmers.
Where modern technologies are introduced there is usually
i n a d e q u a te te c h n i c a l b a c k u p , b o t h i n te r m s o f
mechanics/technicians and availability and affordability of
spare parts. These include anything from tractors and
harvesters to irrigation pumps and systems. The more
sophisticated a technology is, the higher are its requirements
in terms of physical infrastructure and maintenance services.
These constraints call for approaches and strategies adapted
to the conditions under which farmers have to operate. In
most areas of Africa local farmers have themselves developed
appropriate approaches and technologies that are adapted to
the challenges confronting them. Rural farmers have over the
years used indigenous knowledge such as mulching,
intercropping, simple erosion control measures, etc. to
maintain and improve soil quality and yields. The Land Care
programme in South Africa developed what it believed to be
the best practice for small farmers to grow maize: in a field trial
leader farmers had to compare this best practice with their
own practice in order to prove to farmers in the area how much
they could improve their maize production by adopting the
best practice. The outcome was a big surprise: By far the best
yield was obtained by Leader Farmer 4 with his own practice
that he had developed (Figure 1). This is a good example of
where it would be the best approach to start with the
technology of Leader Farmer 4 and from there to improve the
farmer's existing approach and transfer that to other farmers. It
is certain that there are many similar examples from other
countries in Africa.
1
Michiel C. Laker ,
Emeritus-Professor of Soil Science, University
of Pretoria, Pretoria, South Africa.
Postal address: 477 Rodericks Road, Lynnwood 0081,
South Africa.
Cellular phone: + 27827855295
E-mail: [email protected]
Nature & Faune Volume 30, Issue No. 1
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4
Yield (t ha-1)
3.5
Farmer practice
Best practice
3
2.5
2
1.5
1
0.5
0
1
2
3
4
Leader farmer
Figure 1. Maize yields in farmer-led trials: Magusheni, Eastern Cape, South Africa
Good crop yields cannot be attained on a sustainable basis
without good soil classification and especially correct land
suitability evaluation. In the past few decades there has been
an explosion of interest in the numerous local indigenous soil
classification and land evaluation systems of population
groups and communities throughout Africa. Most important is
the growing realization of the value of these by scientists.
Farmers and soil scientists are key people to be involved in
any drive towards sustainable soil management. Farmers
have their accumulated knowledge of what can be done
successfully with soils on a given landscape (mountain slope,
dryland, wetlands, coastal strips etc.) and are cognizant that
soil suitability depends on what the farmer wants to grow
there. Even desert sands can grow a lot of food and forestry
and horticulture can thrive very well in some of the soils
described in general terms as infertile. Soil scientists have the
basic scientific knowledge required to forecast what will
happen when a new or adapted land use or management
system is introduced. Success can, however, not be achieved
without the involvement of and effective close interaction with
others, like agronomists, horticultural scientists, engineers,
extension officers, etc. In many cases effective interaction with
decision makers and politicians is also essential.
Unfortunately farmers are usually not involved in decisionmaking on agricultural development. Likewise soil scientists
are often not involved or their advice and recommendations
ignored or rejected in decision-making processes. The
outcome too often leads to project failure, soil degradation
and negative impacts on farmers and their families. Peter
Ehrlich, population geneticist from Stanford University once
stated that soil is the most neglected resource on earth.
Experiences of soil scientists worldwide and my own
experiences, especially when it comes to small farmer
development, are that soil scientists are probably the most
ignored scientists in the world (Laker, 2000). So, in this
International Year of Soils the focus should not only be on the
soils of Africa, but also on the soil scientists of Africa and the
farmers they work with.
In marginal or non-deal soil and climatic conditions, selection
of appropriate crops and especially adapted cultivars is
critically important for success. Small-scale farmers in Africa
have over centuries consciously developed cultivars that are
highly adapted to their conditions by each year collecting
seed from plants that gave the best yields. Introduction of socalled high yielding varieties that are bred for top performance
under ideal conditions fails when they are introduced in
marginal areas, performing worse than the local cultivars. By
tapping into the extremely valuable gene pools of which the
small scale farmers have been the custodians for centuries
plant geneticists/breeders could develop ranges of more
productive cultivars that are adapted to different non-ideal
situations.
My own experience highlighted the importance of first
listening to farmers. My contact with indigenous small-scale
agriculture started on the hills of East Pondoland in the far
northeastern corner of the present Eastern Cape province of
the Republic of South Africa during my June university
holidays in 1960. The area has good rainfall (700 to 1 000 mm
per annum) and soils that are physically good, but are acidic
and have very low phosphorus content. Somehow one farmer
discovered that I was an agricultural student and came to ask
for advice on how he could grow his maize better. Firstly, I
became aware that here was someone who really wanted to
improve his crop production. Secondly, I realized that, despite
my university knowledge and practical experience of
agriculture on my uncle's farm since childhood, I did not
actually have answers to his questions. I could, for example,
not advise him to apply fertilizers, because there was nowhere
that he could get fertilizers and no means to get it to his area
over the very bad roads with almost no motor transport.
Manure could be an option, but that was scarce, being in
demand for many other essential purposes in and around the
homes. Although I could not give him clear advice, we had a
number of intensive discussions on agriculture. Somehow
something good must have come from these for him, because
a few years later I received a Christmas present from him
through the mail thanking me for the helpful conversation.
My big lesson from then on was that one must never go with
"clever" preconceived ideas into any farming community. First
talk with the farmers. Listen to them. Do not "lecture" them.
Nature & Faune Volume 30, Issue No. 1
4
Make observations. "Good observation is good science and
can be more useful than statistically planned experiments."
(Julian Thomas, 2012) Then form a picture and try to develop
suggestions together with the farmer(s). Later on I learned a
lot from amazing observations by farmers themselves and
technologies used by them. I would like to share a few
experiences.
Much later in my career (in 1995) I participated in a study tour
of indigenous soil and water conservation practices in
Burkina Faso and Niger. On the first day of field visit I
became frustrated by what we were told by our field host from
Europe. The area had planting pits and after making my own
observations, I asked him that evening: "Did you see that they
plant the crops on the mounds of soil next to the pits and not in
the pits?" His reply was: "That is nonsense. They plant in the pits
and not next to it, because the water collects in the pits." The
next day we were taken to a community which was described
beforehand as very progressive. From our bus to the meeting
place we passed a field in which the crop was planted on the
mounds and not in the pits. I pointed it out to him and
requested that he ask them why they plant on the mounds
and not in the pits. When he did that, the spokesperson for the
community gave a long reply in French, which the host then
translated as: "If it is a shallow soil we plant on the mound. If it is a
deep soil we plant in the pit. If it is a soil that is not crusting
(sealing) we do not make pits." These clever adaptations by
farmers of a technology to specific situations all made perfect
scientific sense.
water conservation (capturing of spring rains) and serious soil
physical degradation like crusting and compaction.
A study in Zambia found that individual small-scale farmers
produced excellent crops on the fertile soils along the banks
of the Zambezi river (Plate 1), but they had to severely restrict
their production, because the local market was very small
(Kwaw-Mensah, 1996). They actually introduced a quota
system between themselves so that everyone could get some
share of the market. There was a big market in Lusaka, but due
to poor roads and transport services they could not get their
produce to that market. Further north along the Zambezi
production suddenly expanded when a big supermarket
group opened in the copper belt and sent in their trucks to
collect vegetables directly from the farms (Daka, 2001). With
the expansion traditional bucket irrigation became too
cumbersome and alternative irrigation systems had to be
found. In the end two systems that were both well-known
elsewhere in Africa were introduced. The first was the treadle
pump (human foot operated pump). The farmers initially
rejected it, but when it was redesigned according to the
wishes of the farmers and the construction materials modified
so that artisans in the villages could build and maintain the
pumps, 2 500 pumps were adopted within three years. The
second was clay pot irrigation. In field experiments it was
found that with clay pot irrigation a variety of vegetable crops
could be grown with only 30 to 50% of the water that was used
with the traditional local system.
A striking feature of the successful soil and water conservation
strategy in Burkina Faso was that it was completely
community based. Decisions were made by individual
communities. Government did not dictate what had to be
done and how it had to be done, but was available in the
background for advice and support as and when requested
by a community. It is very important to provide advice and
support on this basis.
In some Southern African countries ox-drawn rippers (chisel
ploughs) have been used for a long time, using well-planned
strategies. In the traditional Xhosa area of South Africa in the
northeast of the Eastern Cape province, between the Kei river
in the south and the border with KwaZulu-Natal province in
the north, it was used in what the local people call the Gelesha
system. In this system the soil is ripped in the middle of winter,
just after harvesting maize or sorghum. This opens up the soil
surface for effective infiltration of the significant amounts of
rain in spring which it is important to capture effectively in the
soil because the area is characterized by the mid-summer
droughts which are common along the eastern seaboard of
Africa. Furthermore, the oxen are still in a good condition in
middle winter, but by the end of winter they are generally in a
poor condition and would not have the strength to pull the
ripper through the hard dry soil. Unfortunately the system
largely disappeared after introduction of government
subsidized tractor ploughing systems. The mechanized
system did not follow the Gelesha approach in terms of timing
of cultivation and type of implement used, resulting in poor
Plate 1 – Crop production by a small scale commercial farmer
on the banks of the Zambezi River in Zambia. (Also note the
tomato “trees” on the right and at the back.)
Farmers in Africa generally have a good idea of what to do and
how to do it on different soils in different areas, considering the
different types of constraints within which they have to
operate. I believe that they would like to improve their farming,
provided that it is done in a sensible way. I believe that this
should form the basis from which to systematically improve
skills and yields in such ways that agricultural, economic and
environmental sustainability is achieved. High-tech farming
depends heavily on the availability of both excellent physical
infrastructure and support services in terms of spare parts,
technicians/ mechanics, agricultural inputs, advisory services,
etc. Where these are not available, it fails.
Nature & Faune Volume 30, Issue No. 1
5
Scientists and governments have to understand each
situation and its limitations correctly and act accordingly.
Agriculture has two primary components, namely the farm
and the farmer. “Agricultural development deals not only with
increased food production, but includes parallel changes in
an entire way of life. Much of the research has either missed
this point entirely, or has not reached it yet . . . The processes of
meaningful change are slow, but must be honoured if such
change is done in the best interest of the beneficiary.”
(Barbara Rosenthal in an MSc seminar at Cornell University,
1977). Change is urgently required in Africa, but it must be
managed with adequate consideration of indigenous soil
knowledge by local resident populations such that its
outcome is constructive.
Africa is a unique continent with unique challenges in regard
to its soil and climatic resources. The high spatial variabilities
in the qualities of soils and the nature of their limitations in
Africa require site-specific solutions. Blanket solutions do not
work (IFAD, 1992). Africa has a very valuable resource in the
vast pool of accumulated knowledge amongst its farmers. By
tapping into this and blending it with the scientific knowledge
of its soil scientists and others a route could be plotted for
improving agricultural productivity on the continent by
means of appropriate sustainable soil management
approaches and strategies. Maybe we should adopt the
slogan which I saw on the wall of the office of Bob Reginato at
the US Water Conservation Laboratory in Phoenix, Arizona:
“We are facing a series of great opportunities, brilliantly
disguised as unsolvable problems.”
References
Daka, A.E. 2001. Development of a technological package for
sustainable use of dambos by small-scale farmers. PhD thesis,
University of Pretoria, Pretoria. 225 pp. Available free at
www.up.ac.za
IUSS Working Group RB 1998. World Reference Base for Soil
Resources: Atlas (E.M. Bridges, N.H. Batjes and F.O.
Nachtergaele' Eds.). ISRIC-FAO-IUSS-Acco, Leuven.
Jones, A., Breuning-Madsen H, Brossard M, Dampha A,
Deckers J, Dewitte O, Gallali T, Hallett S, Jones R, Kilasara M,
Le Roux P, Michéli E, Montanarella L, Spaargaren O,
Thiombiano L, Van Ranst E, Yemefack M, Zougmore R., (eds.),
2013, Soil Atlas of Africa.
European Commission, Publications Office of the European
Union, Luxembourg. 176 pp.
Kwaw-Mensah, D. 1996. Causes of low agricultural
productivity in the Senanga district of Zambia. MInstAgrar
dissertation, University of Pretoria, Pretoria. 152 pp.
Laker, M.C. 2000. Can Africa's soil scientists combat the
threats to the continent's soil and related natural resources?
Plenary lectures, Golden Jubilee Congress of the Egyption
Soil Science Society on Soil and Sustainable Agriculture in the
New Century, Cairo, 23-25 October 2000. pp 39-47.
Oldeman, L.R. 1992. Global extent of soil degradation. ISRIC
Bi-annual report 1991-1992, pp. 19-36. ISRIC, Wageningen.
Rosenthal, B. 1977. The selection of soil mulches for use in
less developed tropical areas. Unpublished MSc seminar,
Cornell University, Ithaca.
Thomas, J. 2012. Unpublished report to M.C. Laker on
research experiences at the Makhathini research station,
South Africa. FAO, Rome. (Note: The Makhathini research
station was established for the purpose of conducting
agronomic research with a view to the development of an
irrigation scheme for small scale commercial farmers.)
IFAD 1992. Soil and water conservation in Sub-Saharan Africa
– Towards sustainable production by the rural poor. Free
Univ., Amsterdam. 110 pp.
Nature & Faune Volume 30, Issue No. 1
6
SPECIAL FEATURE
Tailoring soil fertility management inputs to
specific soil types: case study of a pot
experiment in Rwanda
Pascal N. Rushemuka1 and Laurent Bock2
Summary
Promoting intensive use of fertilizers to boost productivity of
the inherently poor soils of Rwanda requires careful
understanding of crop responses to their application. Using a
multi-scale and nested hierarchy land system reasoning,
composite sub-surface soil samples from four representative
soil types were considered to demonstrate the obligation to
understand the soil spatial distribution at watershed level as a
means of guiding the application of appropriate soil fertility
management inputs to specific soil types. Lime/travertine rock,
cattle manure/ farmyard manure (FYM), fertilizers and their
different combinations were tested to four soil types. Results
confirmed significant different responses between soil types
and soil fertility management input treatments (p ≤ 0.001). It
was observed that for Urusenyi (Entisols), the application of
FYM has the ability to improve the fertilizer response. However,
because of the good yield of the control, the intensive use of
FYM can be a recommendable option. For Inombe, all the
treatments where NPK was included gave definite yield
increases, which is significantly higher than the treatments
where NPK was not included. In this soil type the
recommendable treatment was the combination of manure
and fertilizers. For Umuyugu/Mugugu (Oxisols) and
Nyiramugengeri (Histosols), the response in all treatments
without lime was insignificant. In contrast, the effect of lime was
spectacular and significant vis-à-vis to the non-limed
treatments. In these two soil types, the best treatment was the
combination of lime, FYM and fertilizers. This experiment
confirmed the idea of tailoring soil fertility management inputs
to specific soil types at watershed level.
Bassols and Zink, 2006; Barrios et al., 2011) have a precise and
accurate mental soil map with a very accessible soil
nomenclature. At the same time it has been observed that
without systematic consideration of different soil types at
watershed level, soil scientists in Rwanda have been unable to
determine soil-specific fertilizer recommendations for the
main crops of the country after now more than 50 years of soil
fertility management research (Rushemuka, 2014a). In these
circumstances only generic/blanket/blended
recommendations are formulated to the entire national
territory without any consideration to the diverse AEZs and soil
types. Therefore, farmers lack the precise recommendations
for their specific soil types (Steiner 1998). This situation makes
interventions like crop response to fertilizers more erratic and
less profitable (Rutunga, 1991; Sanchez et al. 1997), hence the
low adoption of promoted fertilizer technologies (Steiner,
1998). Therefore the question is posed as why scientists
should continue to fail/ignore/overlook to integrate scientific
and farmers' soil knowledge and build soil fertility
management strategy and draft extension messages on the
farmers' accessible soil nomenclature system? This study
tested the crop response to the application of lime, manure,
fertilizers and their different combinations. The objective was
to demonstrate that different soil types occurring in different
land units of the same watershed may need different soil
fertility management recommendations. The overall idea is
that, at watershed level, the soil type is the fundamental soil
fertility management unit and that the integration of the
farmers' and scientific soil names may help to make the soil
fertility management extension messages clearer and more
accessible and rational. Therefore, this study is not only a
traditional pot experiment but more importantly a practical
example of how farmers' and scientific soil knowledge can be
integrated to solve practical land-related problems as
recommended by WinklerPrins (1999).
2 Materials and methods
1 Introduction
The Rwanda national territory is divided into different AgroEcological Zones (AEZs) at a scale of 1:250,000 (Delepierre,
1974). However, due to complex relief and parent materials,
there remains important soil variability within each AEZ
(Steiner, 1998). Rwanda has also a national comprehensive
soil map (Birasa et al., 1990) at a more detailed scale
(1:50,000). This soil map is known as CPR (for Carte
Pédologique du Rwanda). Still, due to a number of reasons
(Rushemuka et al., 2014a, b, c), this soil map does not help to
totally overcome the problem of soil type variations over short
distance within one AEZ (Steiner, 1998). In addition, in the
complex biophysical environment of Rwanda, it might be
unrealistic to propose a more detailed soil map as this would
imply prohibitive cost without really being able to solve the
core problem. On the other hand, it has been observed that
farmers in Rwanda (Habarurema and Steiner, 1997; Steiner,
1998; Rushemuka et al., 2014) like many others worldwide
(WinklerPrins, 1999; Barrera-Bassols and Zink, 2003; Barrera-
2.1. Soil sampling
Composite soil sampling was done, taking into account land
units, CPR soil mapping units (Birasa et al., 1990) and farmers'
soil nomenclature. Four farmers' soil types were considered in
four land units along the slope (Table 1). Soil samples were
taken at 25 cm depth with the help of an auger. Each
composite soil sample was a mixture of 10 composite samples
taken in 10 farmer's fields of 0.5 ha (on average) for each soil
type under the same land use. Laboratory analysis of
1
Pascal N. Rushemuka. Senior Agri-Environmental Soil Scientist
Rwanda Agriculture Board (RAB).
Box. 5016. Kigali, Rwanda.
E-mail: [email protected]
Tel.: +250783471871.
2
Laurent Bock, Professor of Pedology
Liège University (ULg)-Gembloux Agro-Bio Tech/Belgium.
Box: 5030 Gembloux (Belgique).
E-mail: [email protected]
Tel.: +32081622542/ +32081622538.
Nature & Faune Volume 30, Issue No. 1
7
composite soil samples, which involved different soil properties: particle size, soil pH (water and KCl), total organic carbon, total
nitrogen and exchangeable bases, was conducted in the laboratory at the 'Centre Provincial de l'Agriculture et de la Ruralité' in
Belgium. Results are presented in Table 2.
Table 1 . Soil type according to farmer and scientific soil knowledge in relation to the land units
Land unit
Soil
number
Soil description
Farmers’ Soil
Types
Connotation
Scientific (family) Soil Taxonomy (1975) after
CPR [Carte Pédologique du Rwanda soil map]
Soil 1
Interfluves
Urusenyi
Gravely soils
Loamy-skeletal, mixed, non-acid, isothermic
lithic Troportents
Soil 2
Shoulder
Inombe
Sticky soils
Clayey, kaolinitic, isothermic, humoxic
Sombrihumult
Soil 3
Back slope
Umuyugu
Friable soils
Clayey, kaolinitic isothermic Sombrihumox
Soil 4
Valley
N.mugengeri
Tissue soils
Euic, i sohyperthermic typic Troposaprits
Table 2 . Texture and chemical properties of A horizon
Soil
No
Gr
Cl
Si
Sa
pH
Wa
pH
KCl
∆pH
OC
(%)
TN
Ca
Mg
%
K
CEC
Cmol/kg
1
37
27
17
56
5.7
4.9
0.8
2.3
0.2
11
5.4
0.99
0.3
6.9
2
7
34
16
49
6.0
4.9
1.1
1.4
0.1
9
3.8
1.89
0.1
7.1
3
0
46
13
42
4.5
4.1
0.4
2.6
0.2
12
0.5
0.16
0.1
3.7
4
3
32
26
43
4.3
4
0.3
10
0.2
15
0.5
0.08
0.1
3.8
traditional farmers' soil fertility management practice.
F4. NPK: to test the response to inorganic fertilizer as
new input being widely promoted.
F5. Lime + FYM: to assess the opportunity of
introducing lime in farms where manure gave poor
results.
F6. Lime/travertine + NPK: to evaluate the effect of lime
production where fertilizers gave poor results.
F7. NPK + FYM: to test the interaction between FYM
and fertilizer as a sustainable solution.
F8. Lime + FYM+ NPK: to test the interaction between
lime, FYM and fertilizer for the extremely acid and
depleted soils.
Gr = gravel; Cl = Clay; Si = Silt; Sa = Sand; Wa = Water; ∆pH = pH
(Water) – pH (KCl) OC = Total Organic Carbon; TN = Total
Nitrogen; CEC = Cation Exchange Capacity
2. 2 Matching soil types and appropriate inputs
A pot experiment was conducted from May 2011 to August
2011 to demonstrate the need to tailor soil fertility
management to specific soil types. The experiment was
conducted at Mamba hill in the greenhouse of the Faculty of
Agriculture of the National University of Rwanda (NUR). The
test plant was the Sorghum bicolor (L.) Moench, variety IS
21219, from ICRISAT.
Ÿ
C/N
Experiment layout and treatments
The trial was a factorial Randomized Complete Block
Design (RCBD) three times replicated. Two factors
were considered: soil type (S) with four levels and
fertilizer type (F) comprising eight treatments, giving a
total of 96 pots. Different treatments were defined to
test different hypotheses.
F1. Control or zero input: the reference treatment; to
test the soil type's natural fertility potential.
F2. Lime/travertine; to test the need for liming in the
acid soils of Rwanda.
F3. Farmyard Manure (FYM): to test response to FYM;
Ÿ
Input application and trial set up
Double polyethylene pots 4 cm deep and 16 cm wide
were used to contain soils and drainage water. Each
soil substrate was put into a set of two pots one
containing another. In the inner pot containing the soil
substrate, four little holes were made in the bottom to
allow the drainage of excess water. The role of the
outer pot was to collect water draining from the soil in
order to return it to the soil in the inner pot to avoid
nutrient loss. in each pot soil was homogeneously
mixed with amendments according to treatments.
Nature & Faune Volume 30, Issue No. 1
8
The following inputs rates were used:
1 kg of soil/pot
0.15 g of NPK per pot: equivalent of (51 kg of N, 51 kg of K2O, 51 kg of P2O5)/ha or 300 kg of NPK 17-17-17 ha-1, the
blanket recommendation used for sorghum in Rwanda.
Ÿ 5 g of FYM per pot: equivalent of 10 t/ha, the general recommendation in the area.
Ÿ 4.2 g per pot of lime (Mashuza travertine: 40% of CaO.): equivalent of 8 t/ha of travertine.
Ÿ
Ÿ
Input dose per kg was calculated assuming 2,000,000 kg of soil/ha on a basis of a soil depth of 15 cm and 1.3 soil density (Brady
and Weil, 2002).
Ten seeds were planted per pot. After germination these were thinned to seven per pot. The pots in each block were rotated
every day to ensure even distribution of light and avoid biased results..
Ÿ
Trial management and data recording
Watering of the pots was done on a regular basis every two days. The water rates were calculated considering the soil
water retention capacity previously determined. Every day of watering, the drainage water collected in the outer pot was
recycled into the soil. Sorghum biomass yields were harvested three times at 28 day intervals after planting. Fresh
weight of the plants (g) was recorded and the means for the three cuts was calculated.
Ÿ
Data analysis
Statistical analysis was performed using the GenStat software, (12th editions). Differences in various treatments were
tested using “two–ways analysis of variance (ANOVA2) in Randomized complete Block design, with least significant
mean differences at 5% probability level. The mean yield separation was done using Duncan test.
3. Results and discussion
Our results showed significant differences between soil types and treatments and the absence of interaction between soil types
and treatments (p < 0.001) (Fig1).
5
4 .5
sed
Ǻ
p<0.001
4
Lime
3 .5
3
FYM
2 .5
NPK
2
Lime+FYM
1 .5
LIME+NPK
1
FYM+NPK
0 .5
LIME+FYM+NP K
Ö
Nom be
Yugu
G engeri
Figure 1Mean sorghum biomass yields expressed in grams per pot of 1 kg of soil (g/pot) of three cuts: crop response to the soil
type and soil fertility replenishment treatments. In this figure Senyi= Urusenyi; Nombe= Inombe; Yugu= Umuyugu; Gengeri=
Nyiramugengeri. Sed=standard error deviation.
The mean separation showed that the different soil types could be grouped into three fertility categories (Table 3). In this table it is
shown that Urusenyi is the most productive and that Inombe is the second while the Umuyugu and Nyiramugengeri are the least
productive. This is explained by their respective chemical soil properties such as pH, Ca and Mg (Table 2). This is consistent with
farmers' perceptions (Rushemuka et al., 2014a). The implication is that farmers know that they need different soil fertility
Nature & Faune Volume 30, Issue No. 1
9
management strategies and that they know the differences between their soils. But understanding different soil types and taking
into their spatial distribution during the implementation of soil fertility management strategies is a big challenge for decision
makers, scientists and extensionnists in agronomic sciences (e.g. soil fertility management and crop selection and breeding)
mainly because of poor links between pedology (soil map) and agronomists (Steiner, 1998; Rushemuka et al., 2014b). There is
also a lack of understanding and appreciation of the valuable indigenous knowledge of local farmers. As a consequence
decision makers in policy and practice typically use insufficiently the research-based and farmers' knowledge available and
researchers typically produce insufficiently knowledge that is directly usable (Wiechselgartner and Kasperson, 2010). This
would imply that the communication gap between pedologists and agronomists on the one hand and between scientists and
extensionists and farmers on the other hand should be filled (Rushemuka et al., 2014b).
Table 3. Mean yield separation of different soil types
The statistic test also showed that different treatments produced significantly different effects in each soil type (Table 4). For
Urusenyi, the Control has a good biomass yield in the same mean separation category with many proposed treatments (Table 4).
This is consistent with the good properties of this soil (Table 2). Striking however could be the fact that treatments with FYM (F3)
and FYM + NPK (F6) showed inferior biomass yield compared to control (F1) and lime alone (F2). The difference between the
Control and the FYM is even significant. The explanation could be an external fact: indeed after the first cut where these
treatments (F3) and (F6) had got higher biomass yields compared to the control (data not shown) a certain fungal population
(probably due to FYM mineralization) was observed in these treatments which reduced the yield after the first cut. Lime (F2), NPK
(F4) and Lime + NPK (F6) gave identical results, a bit higher than the control, but these increases are not statistically significant
(Table 4). All three are significantly higher than Lime + FYM (F5). Interesting is that whereas FYM (F3) and especially Lime + FYM
(F5) gave negative results, in contrast when FYM was applied together with NPK, i.e. FYM +NPK 5 (F7) and Lime + FYM + NPK (F8),
FYM actually somewhat boosted the positive reaction from NPK. In this combination FYM is expected to have raised the soil CEC
thereby improving fertilizer use efficiency in these soils of small CEC (Table 2). The soil pH and Ca and Mg levels were already
good (Table 2).
For Inombe neither lime nor FYM treatments: Lime (F2), FYM (F3) and Lime + FYM (F5) gave any response, neither negative nor
positive. This is normal because the soil pH and Carbon content could not suggest big response of these inputs (Table 2). In
contrast all the treatments where NPK was included, alone or in combination with lime and/or FYM (F4, F6, F7, F8), gave definite
yield increases, which are significantly higher than the treatments where NPK was not included (Table 4). This could be
explained by the low saturation of the complex of this soil type. The F7 results suggest that Inombe soil type requires the
combination of manure + fertilizers for its optimum production. In this combination FYM is expected to increase the CEC while the
fertilizers are expected to saturate the soil complex. The results from this experiment on this soil type are consistent with Rutunga
and Neel (2006) who observed that lime is needed in soils with pH <5.5.
For the extremely acid (pH<5) and depleted Umuyugu soil (Table 2) only treatments where lime was included: Lime (F2), Lime +
FYM (F5), Lime + NPK (F6) and Lime + FYM + NPK (F8), gave definite positive responses that are significantly higher than the
control (F1) and all the non-lime treatments: FYM (F3), NPK (F4) and FYM + NPK (F7) (Table 4). The treatments without lime gave
basically no response, neither positive nor negative. The same situation was observed by Rutunga and Neel (2006). The
response with Lime (F2) alone was smaller than where FYM and/or NPK were applied together with the lime. The differences
between Lime + FYM (F5) and Lime (F2) and Lime + NPK (F6) were not significant (Table 4) but the difference between Lime +
FYM + NPK (F8) and Lime (F2) was highly significant. These results clearly indicate the importance of liming, but that lime alone
does not give good yields, it has to be accompanied by manuring and fertilization. The recommendation for this soil type is the
combination Lime + FYM + Fertilizers. In this combination, lime is expected to have raised the soil pH to at least 5.5, to supply Ca
and Mg as plant nutrients and to have improved the P use efficiency (Rutunga and Neel 2006). The fertilizers are expected to
have supplied the N P K nutrients while the FYM is expected to have increased the nutrients by increasing the soil CEC and by
supplying additional nutrients. On the other hand, applying fertilizers or manure to such soil just gives absolutely no response
without liming. The same situation was reported by Rutunga and Neel (2006).
Nature & Faune Volume 30, Issue No. 1
10
For the extremely acid and depleted Nyiramugengeri (Table 2) soil the treatments where lime was not included also gave very
little response, as could be expected after the experience of Umuyugu soil. Response from Lime alone (F2) was almost identical
to that for the Umuyugu soil. In this soil there was an important difference, namely the good response with FYM where it was
applied together with lime (F5), as good as for Lime + NPK (F6). Where FYM was applied together with lime and NPK (F8) it also
boosted the response clearly above where only lime and NPK (F6) was applied. So, here is a soil where it was definitely beneficial
to apply FYM – together with lime and NPK for the same reasons stated for Umuyugu soil.
Table 4. Biomass yield mean separation for different treatments in different soil types
Average sorghum biomass yield [expressed in grams per pot of 1 kg of soil (g/pot)]
Treatment
S1
S2
S3
S4
F1
3.48abc
1.80a
0.687a
0.821a
F2
3.74abc
1.80a
1.547b
1.369c
F3
3.17ab
1.88a
0.691a
0.903ab
F4
3.65abc
1.898b
0.991a
0.839a
F5
2.88a
2.382a
1.764bc
2.152d
F6
3.72abc
2.406b
2.060bc
2.204d
F7
4.03bc
2.519b
0.834a
1.196bc
F8
4.25c
2.627b
2.222c
2.579e
Prob
0.063
0.002
<.001
<.001
SED
0.389
0.1992
0.249
0.1456
Overall, these results are consistent with previous studies undertaken at field level (Rutunga, 1991) that showed that in Rwanda,
some soils (pH> 5.5) can still produce good crop yields with the application of manure, other soils (pH = 5.2-5.5) need the
combination of fertilizers + manure while other soils (pH< 5.2) need the combination of lime +manure + fertilizers. They are also in
line with Steiner (1998) who observed a soil fertility gradient with the upper soils yielding more than the lower slope. The practical
implication is that we need to understand different soil types in terms of their names (scientific and local), their spatial distribution
to be relevant to our stakeholders, efficient vis-à-vis the use of limited soil fertility management inputs and to sustainably manage
our environment.
4. Conclusion and recommendations
This study has shown that for the four soil types tested for crop response to lime, manure and fertilizers and their different
combinations were statistically different and were grouped into three fertility management classes. The Urusenyi was the most
productive and the Inombe was the second while the Umuyugu and the Nyiramugengeri was in the last category. Results
showed also that the proposed treatments were statistically different in each soil type. It has been observed that Urusenyi could
still produce good crop yields using the FYM. The Inombe for its optimum production requires the combination of FYM and
fertilizers. The Umuyugu and Nyiramugengeri require the combination of lime + FYM + fertilizers. Overall, this experimentation
confirmed the need of tailoring soil fertility management inputs to specific soil types.
Given the above-demonstrated importance of the farmers' soil knowledge system the practical implications for Rwanda is that it
(1) could be described, mapped and bridged with the scientific knowledge system at least at representative watersheds in each
Agro-Ecological Zones (2) should be taught at University as a module of the course of pedology (3) should be recognized and
adopted as the National Soil Classification System whereas Soil Taxonomy, the language of the CPR ( Carte Pédologique du
Rwanda), could play the role of one of the correlation systems for scientific communications (4) should be used to set up landrelated strategic plans and to communicate extension messages. This could be easier in Rwanda as everybody countrywide
speaks the same National Language: the Kinyarwanda.
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Rushemuka N. P., Bizoza R. A. Mowo J. G., Bock L., (2014c).
Farmers' soil Knowledge for Effective Participatory Integrated
Watershed Management in Rwanda: towards soil-specific
fertility management and farmers' judgmental fertilizer use.
Agric. Ecosyst. and Environ. 183, 145-159.
Rutunga V., Neel H. (2006). Yield trends in the long-term crop
rotation with organic and inorganic fertilizers on Alisols in
Mata (Rwanda). Biotechnol. Agron. Soc. Environ. 10 (3), 217228.
Rutunga V., (1991). Essaie de synthèse des connaissances
acquises sur la fertilisation des cultures au Rwanda (± 19601990). Minagri. Kigali/Rwanda.
Sanchez, P.A.; Shepherd, D., Soule, M.J., Place, F.M ., Buresh,
R.J., Iza, A.N., Mokunye, A.U, Kwesiga, F.R, Ndiritu, C.G,
Woomer, P.L. (1998). Soil fertility replenishment in Africa: An
investment in Natural Resource Capital. In. Replenishing soil
fertility in Africa”. SSSA Special publication number 51.
Madson, Wisconsin, USA: Soil Science society of America,
American Society of Agronomy, 1-46.
Steiner, K.G., 1998. Using farmers' knowledge of soils in
making research results more relevant to field practice:
Experience from Rwanda. Agric. Ecosyst. and Environ. 69,
191-200.
Weichselgartner J., Kasperson R. (2010). Barrier in the
science-policy-practice interface: Toward knowledge-actionsystem in global environmental change research. Glob.
Environ. Change 20, 266-277.
WinklerPrins, A. M.G.(1999). Insights and Applications Local
Soil Knowledge: a Tool for Sustainable Land Management,
Society Et Natural Resources, 12:2, 151-161.
Nature & Faune Volume 30, Issue No. 1
12
OPINION PIECE
The living soils of Africa
Lamourdia Thiombiano1
On the occasion of the 2015 International Year of Soils, it is
important to revisit the evolution of soils knowledge in Africa
and the major features of its development. The celebration of
the Year of Soils through this special publication calls for
valuing soils as natural resources that deserve greater
attention. Soils are living organisms and their functions within
the ecosystems and within human societies are essential to
survival as providers of nutrients and anchor to the millions of
living plants, animals and human beings of the Earth. Soils
support many other services ranging from materials for house
building to solid base for our roads. Clay which is a finegrained soil material possesses healing properties, making it a
powerful weapon against a large number of human and
animal diseases. It is also used in the beauty industries. In this
regard the motto of the United Nations 2015 International Year
of Soils: “Healthy Soils for a Healthy Life” is befitting.
Soils and lands are part of the African cultural features and
concepts; they are embedded in community characteristics,
richness and symbols of power. For centuries, land has been
the subject of focus in terms of conquest, wealth and/or peace
and security. The capacity of a family to feed itself, a
community to ensure food for its members, and a village or a
Kingdom to build and strengthen its fame and power, were
linked to the extent of land and soil fertility it possess. The
vastness of fertile lands for agriculture, expanse of wetlands
and rivers for fisheries, immensity of rich and diversified forests
for timber and wildlife, as well as extensive grazing lands
helped to shape the culture and lifestyle of people and
communities. In some Sahelo-Sudanian cultures, burning a
fire was the first act of sovereignty; the extent of land burnt
would be the extent of the primary territory over which the
burner would extend his sovereignty.
Encrusted in cultural heritage, soil knowledge that was
transmitted from generation to generation was used by
communities in assessing the productive capacities of lands
targeted for conquest or settlement. Long exposure to the
environment gave communities the capacity to judge from
soil color, location within the landscape, nature of parental
material, texture and other attributes of soils, what to expect in
terms of productivity and for what main uses (Thiombiano,
1995).
Soils and land were considered as sacred because of their key
role to communities, in providing food, supporting the forest
and water resources, agriculture, hunting and fishing, material
for building huts and houses, pottery for cooking and crop
storage, and in welcoming human beings in fine after their life
on earth. Throughout history due consideration was given to
the way soil should be managed, to maintain its health to the
benefit of human beings, to the glory of a community or a
Kingdom. Spiritual values as well as packages of traditions
and technologies were developed to ensure that soils are
used for the best, and that the resources harvested for food
was done in a sustainable way. In a number of communities
taboos were set up to protect the soils and maintain them in
good health.
During the colonial period other types of approaches and
methods of soils characterization and classification, soils and
land and water management were introduced through
modern knowledge systems. For example, in the 1950's the
current Democratic Republic of Congo (DRC) hosted one of
the World Soil Congresses, the only one so far, to take place in
Africa . Soils scientists from all over the world participated in
this great event at which the discovery of Ferralsols and
Luvisols/ Lixisols under the dense equatorial forest was
among the amazing revelations for a number of soil specialists
(ISSS, 1954)
Later on, in the 1960s, the French and Belgian classification,
and the American Soil Taxonomy were progressively adopted
across the continent, depending on the patterns of colonial
influence and the University in which national specialists in
the subject matter were trained. Soils then became an object
of scientific curiosity and classification, a provider of raw
materials for food and industries within and outside the
continent. The land and soil's spiritual nature and the taboos
that were indeed its protective cover, were challenged within
the minds of new generations of African agronomists and
land- users, to allow intensive production. The use of chemical
inputs increased. Immense areas were deforested and put
into agricultural production to feed the people and for export,
to grow cash crops and for wildlife. Together with an
increasing population and diversified and even sometimes
conflicting uses of soils, the negative impact on soils became
increasingly pronounced. In modern times, human beings
tend to forget that soils are living bodies; that soils can breathe
through the many thousands of microorganisms and fauna
they host. Modern agriculture and forest harvesting
techniques displaced traditional sustainable agricultural
methods: the wisdom from the past in managing soils based
on justified present-day needs, and the needs of future
generations, became scarce. Sustainable indigenous
technologies were gradually pushed away.
In the seventies, desertification emerged as a predominant
concern for the African continent and the world. It was then,
time to rethink about how to revive the wisdom and regain
trust in the spirits that live in the soils, the wisdom and best
practices from the past. An increasing number of conferences
were organized all over the world, starting from one in Nairobi
focusing on desertification (UN, 1977).
1
Lamourdia Thiombiano
PhD, Soil specialist. FAO, Sub Regional Coordinator for North Africa;
FAO Representative to Tunisia 43 Rue Kheireddine Pacha, Belvédère
TUNIS .
Mailing Address: PO BOX 300, 1082 Citè Mahrajène, Tunis Tunis .
Telephone: +216-71-906553 ; +216 71 903 396
Fax: +216-71-901859
Email: [email protected]
Website: http://www.fao.org/neareast/
2
Latin expression for “in the end”
Nature & Faune Volume 30, Issue No. 1
13
Forest plantations and afforestation programs as well as a
number of technologies and improved practices to fight
desertification, were generated by research and applied for
better soil management (Thiombiano and Tourino, 2007) .
Several National Soil Bureaus were set up and developed to
provide better knowledge on soils through donor funding
and support from national budgets. Maps at various scales
were produced in relation to the types of soils, their suitability
for crops, forests, livestock and aquaculture. Land use Master
Plans and soil suitability maps were produced and made
available to policy makers and land managers, using modern
soil classification methods and information from historical
archives.
With an increasing diversity of soil classification systems,
there was a need for correlation and harmonization of the
complex terminology and divergent languages used by soil
specialists. A major step was the development of the World
Reference Base for Soil Resources (WRB), by the
international soil science community. As a result, in the 1990s
overseas WRB scientists became aware of some of the most
important soils of Southern Africa, especially during a field
workshop in South Africa. Moreover, WRB tools were well
accepted and adopted particularly by the World Soil
Congress in 1998 in Montpellier, France (IUSS, 1998). Africa
significantly contributed to the testing and improvement of
the WRB through the successful Post Congress Tour B7. A tour
that took more than one hundred of congress participants
through West Africa: from the sandy dune soils of Dori town in
the Sahel of Burkina Faso, to the marine dune soils of Abidjan
in Côte d' Ivoire. During this Tour, many high profile soil
science specialists from six continents experienced the
sacred linkage between soils and the lives of human beings, in
rural and urban areas. Through cultural performances, direct
interaction with land-users on farms and in open soil pit areas
(which are a source of laterite blocks for building traditional
houses), participants acknowledged the vitality of soils and
their importance for life. The “communion” between African
soil scientists and their fellow specialists from all over the
world was amazing to see, when two meters down in soil pits,
they could jointly describe and discuss soil horizons and
functioning, and potential of these soils for sustainable uses.
Moreover, participants highlighted the importance of
focusing attention on how modern knowledge such as
Information Technology can enable Africa to better capitalize
upon its traditional knowledge and even its beliefs that soil
and land are more than just things but instead are living
"beings".
The recent publication of the Soil Atlas of Africa in 2013
(Dewitte et al., 2013b; Jones et al., 2013a) was another
milestone of a worldwide collaboration, which contributed to
African soil knowledge sharing. Soil types of the continent,
their distribution according to sub regional coverage and their
diverse uses, are illustrated in this Atlas aimed at policy makers,
soil specialists and the public at large. This Atlas is in a way a
marvelous celebration of the African soils.
The celebration of the 2015 International Year of Soils and the
World Soil Day which will be celebrated every year, on 5
December, is a great victory for the millions of land users and
virtually every human being. It should urge and inspire
humanity to take greater care of soils and provide updated
and accurate data and information to policy makers and land
users. We need to reconnect with the wisdom of the past
encrusted in the greetings of an Ethiopian tribe: "May your soil
be fertile".
References
Dewitte, O, Jones A, Spaargaren OC, Breuning-Madsen H,
Brossard M, Dampha A, Deckers JA, Gallali T, Hallett SH, Jones
RJA, Kilasara M, Le Roux P, Micheli E, Montanarella L,
Thiombiano L, van Ranst E, Yemefack M, and Zougmore R ,
2013b - Harmonisation of the soil map of Africa at the
continental scale. Geoderma 211–212 (2013) 138–153 .
http://dx.doi.org/10.1016/j.geoderma.2013.07.007
International Society of Soil Science (ISSS), 1954 - Fifth
International Congress of Soil Science. Transactions,
Proceedings and Report of Excursions. Leopoldville, Congo
Belge . Office of Secretary General. Add Goemarre, Imprimeur
du Roi. 288 p.
International Union of Soil Science (IUSS), 1998 - Resume and
Summaries. Proceedings of the World Soil Congress.
Montpellier, France. Vol I and II
Jones, A., Breuning-Madsen H, Brossard M, Dampha A,
Deckers J, Dewitte O, Gallali T, Hallett S, Jones R, Kilasara M,
Le Roux P, Michéli E, Montanarella L, Spaargaren O,
Thiombiano L, Van Ranst E, Yemefack M, Zougmore R., (eds.),
2013,
Soil Atlas of Africa. European Commission,
Publications Office of the European Union, Luxembourg. 176
pp.
http://eusoils.jrc.ec.europa.eu/
http://acpobservatory.jrc.ec.europa.eu.
Thiombiano L., 1995 - Système de classification traditionnelle
des Sols : Etude des critères et démarche dans les zones
Centre et Est du Burkina Faso. Rev. Agronomie Africaine. AISA ,
Abidjan. Vol.7, n3 : 170-180
Thiombiano L. and Ignacio T., 2007. Status and trends in land
degradation in Africa. Environmental Science and
Engineering. Chapter 2; In Sivakumar M.V.K., Ndang'ui N. (Eds).
Climate change and land degradation; Springer
UN, 1977 - United Nations Conference on Desertification.
General Assembly 32nd Session. 107th Plenary meeting. Pp
106-107.
http://www.un.org/documents/ga/res/32/ares32r172.pdf
Nature & Faune Volume 30, Issue No. 1
14
ARTICLES
Towards a sustainable soil security in subSaharan Africa: some challenges and
management options
Akim O. Osunde1
Summary
Soil is an important natural resource that has an existential
bearing on mankind, directly affecting the quality of life and
human survival. In addition to its role in the sustenance of food
security, soil also plays an integral in the global environmental
sustainability challenges of water security, energy
sustainability, climate stability, biodiversity, and ecosystem
service delivery. The promotion and improvement of a robust
soil system that is capable of adequately playing these roles
therefore becomes an imperative. This underpins the concept
of soil security. The major challenge to sustainable soil security
in many regions of Sub-Saharan Africa (SSA) is extensive land
degradation which manifests as rapid deforestation, soil
erosion, nutrient depletion and declining soil fertility. One of
the most effective management options that are often used to
check these hazards and thus engender sustainable soil
security, especially in low-input agricultural systems, is the use
of nitrogen fixing legumes (NF legumes). The degree to which
a particular legume contributes to soil security depends on its
type. While the grain legumes provide nitrogen-rich edible
seeds, their residues serve as mulch and contribute to organic
matter build-up in the soil. The green manure legumes are
grown primarily for use as organic manure and weed
suppression, while the woody legumes provide multiple
services that include the provision of mulch materials, staking
materials and green manure; soil erosion control, nutrient
recycling. To the extent that these contributions by NF
legumes engender soil security and thus enables the soil to
play its role in meeting the global environmental sustainability
challenges, especially as it affects SSA, it can be deduced that
NF legumes offer a potential for the attainment of a secured
continent.
Introduction
Soils constitute a finite resource that is reusable as long as they
are not degraded to the point where it is not practically
possible or economically feasible to reclaim them. Beyond
that point they become non-renewable resources. Soils are
fundamental to life on earth and are a key enabling resource,
central to the creation of a host of goods and services integral
to ecosystems and human well-being. They are the reservoir
for at least a quarter of global biodiversity, and therefore
require the same attention as above-ground biodiversity. A
healthy, fertile soil is paramount to agricultural productivity
and thus sustainable food security. In addition to its role in the
sustenance of food security, soils also play integral roles in the
global environmental sustainability challenges of water
security, energy sustainability, climate stability, biodiversity,
and ecosystem service delivery. The promotion and
improvement of a robust soil system that is capable of
adequately playing these roles therefore becomes an
imperative. This underpins the concept of soil security. This
paper introduces the concept of soil security and its
interrelationship with the other previously recognized global
environmental challenges. It further highlights the challenges
to sustainable soil security in Sub-Saharan Africa and
discusses the role of nitrogen fixing legumes in the sustainace
of soil security. The paper concludes with some
recommendations and suggestions.
Soil security and its interrelationship with the six
global environmental challenges
The term “Soil Security” is a new concept that has arisen in
response to an emerging international concern about the
increasingly urgent challenges facing the global soil stock.
Soil security thus refers to the maintenance and improvement
of the world's soil resources to produce food, fibre and
freshwater, contribute to energy and climate sustainability,
and maintain the biodiversity and the overall protection of the
ecosystem goods and services (Koch et al., 2012, McBratney
et al., 2012). Without a secure soil we cannot be sure of secure
supplies of food, fibre, clean freshwater or of diversity in the
landscape. An insecure soil is short in the potential to act as a
sink in the carbon cycle, and cannot provide a core platform
for the production of renewable energy sources (McBratney
et al., 2014).
.
Soil security and the other global environmental challenges
(food security, water security, energy security, climate change
abatement, biodiversity protection and ecosystem service
delivery) are strongly interconnected and inter-related (Figure
1), as they all have similar characteristics and are addressed
using a combination of dimensions with a focus on providing
services to humanity.
1
Professor Akim O. Osunde (FSSN)
Department of Soil Science & Land Management,
School of Agriculture & Agricultural Technology,
Federal University of Technology, Minna,
PMB 65, Minna. Niger State. Nigeria.
Telephone: (+234) 8035902755, (+234) 8052509990
Email: [email protected] and [email protected]
Nature & Faune Volume 30, Issue No. 1
15
economic properties of soil." (WMO, 2005). Simply put, it is a
permanent decline in the rate at which land yields products
useful to local livelihoods within a reasonable time frame. SubSaharan Africa has the highest rate of land degradation as
they have fragile soils, localized high population densities,
and generally a low-input form of agriculture. It is estimated
that losses in productivity of farmland in SSA are in the order of
0.5-1 per cent annually (WMO, 2005), suggesting productivity
loss of at least 25 per cent over the last 50 years. According to
UNCCD, the consequences of land degradation include
undermining of food production, famine, increased social
costs, decline in the quantity and quality of fresh water
supplies, increased poverty and political instability, reduction
in the land's resilience to natural climate variability and
decreased soil productivity.
Figure 1. Soil security is a major contributor to a number of
global environmental issues, all of which are inter-related
(Source: McBratney et al., 2012).
It is important to highlight the centrality of the soil to human
existence, examine its interrelationship with the six previously
recognized global environmental challenges and hence the
need for its sustainable exploitation and security. A fully
functioning soil is therefore central to solving the big issues of
food security, biodiversity, climate change abatement and
fresh-water regulation. The concept of soil security provides a
useful model that links soil with good outcomes in sustainable
development as shown in Figure 1. The key aim in securing
soil is to maintain and optimize its functionality: its structure
and form, its diverse and complex ecosystems of soil biota, its
nutrient cycling capacity, its roles as a substrate for growing
plants, as a regulator, filter and holder of fresh water, and as a
potential mediator of climate change through the
sequestration of atmospheric carbon dioxide (Koch et al.,
2013). Maintaining the myriad of interactions between these
processes is what gives soil its resilience, productivity and
efficiency in the delivery of ecosystem services.
The challenge to sustainable soil security in SubSaharan Africa
The major challenge to sustainable soil security in many
regions of Sub-Saharan Africa (SSA) is extensive land
degradation which manifests as rapid deforestation, soil
erosion, nutrient depletion and declining soil fertility. The
United Nations Convention to Combat Desertification
(UNCCD) defines land degradation as a "reduction or loss, in
arid, semi-arid, and dry sub-humid areas, of the biological or
economic productivity and complexity of rain-fed cropland,
irrigated cropland, or range, pasture, forest, and woodlands
resulting from land uses or from a process or combination of
processes, including processes arising from human activities
and habitation patterns, such as deforestation, soil erosion
and deterioration of the physical, chemical, and biological or
Given the high levels of nutrient depletion and soil
degradation in many small holder farming systems in SSA,
associated with high economic cost of fertilizers, and the
problems of their availability, the need to explore alternative
soil management avenues becomes imperative. Nitrogen
fixing legumes offer considerable potential in sustaining crop
productivity, maintaining the productivity of marginal lands
and minimizing erosion in low-input farming systems
(Osunde and Bala, 2001).
The role of nitrogen fixing legumes
Nitrogen is the plant nutrient required in the greatest amount
for soil productivity and plant growth. Nitrogen fixing
legumes through the natural process of biological nitrogen
fixation (BNF) in symbioses with root nodule bacteria
(rhizobia) can play a critical role in the achievement of cost
effective, attractive and ecologically sound means of
reducing external N inputs and improving the quality of soil
resources and ensuring the sustainability of soil security.
Worldwide, NF legumes have been reported to fix over 80
million tons of nitrogen annually (Giller, 2001). The amount of
nitrogen fixed varies widely depending on the host NF
legume plant, the rhizobium efficiency, and the soil and
climatic condition of the environment. In addition to their Nfixing capacity, legumes are extremely important in human
and animal diets. Globally, they supply about 33% of human
protein. Apart from the contribution of part of N fixed for the
maintenance of soil fertility, other rotational beneficial effects
of NF grain legumes to a succeeding crop include reduction
of disease incidence and/or weed infestation. The NF green
manure legumes are also commonly used as cover crops to
protect the soil from erosion by maintaining a dense canopy
over the surface of the soil, and are thus mostly useful as cover
crops on steeply sloping lands and for the control of
pernicious weeds (Giller, 2001). The NF trees and shrubs
provide multiple services to the farmer in the form of
agricultural benefits (plant stakes, mulch materials, green
manure, animal fodder etc), environmental benefits (shade,
soil erosion control, nutrient recycling) and socioeconomic
benefits (fruits, vegetables, nuts, building materials etc) (Kang
et al., 1990).
Nature & Faune Volume 30, Issue No. 1
16
Concluding recommendations and suggestions
In conclusion, I wish to make the following recommendations
and suggestions on ways to mitigate the challenges of soil
degradation and thus ensuring a secure soil in Sub-Saharan
Africa.
The resilience of most soils in SSA is inherently low hence the
high level of degradation upon cultivation. The lack of a body
charged with the supervision of the use, management and
treatment of soils and the coordination of projects and
researches on soils in most of the SSA countries has
degenerated into progressive abuse of the soil through
indiscriminate deforestation, bush burning, grazing, land
clearing etc. This must not be allowed to continue.
1. The establishment of a well-structured National
Institute of Soil Research in each of the SSA
countries, charged amongst others with compiling
research information on the capability of soils for
different crops, developing guidelines for soil
conservation and management in the different agro
ecological zones of SSA, carrying out basic research
that would generate baseline data applicable at the
farmer's level is imperative and desirable. The
establishment of such Institutes will go a long way in
arresting the deteriorating situation of incessant soil
abuse.
2. Governments across the SSA countries must make
conscious efforts to strengthen the extension
services to adequately disseminate information at
farm gate on soil suitability, soil conservation
strategies and other soil management technologies
for sustainable soil security and food production
3. Governments across these countries should
embark on building a critical mass of educated
farmers using the students in agriculture in the
tertiary institutions as the focal point. It is a well
known fact that the educated farmer would easily
understand and accept information that emanate
from research and development concerning the
various technology options which could overcome
land degradation. Thus conscious efforts should be
made to encourage the study of Agriculture and Soil
Science in particular through special concessions
such as scholarships, bursaries or fees subsidy.
Each and every one has the responsibility of ensuring the
sustainability of our soil not only through our actions but also
by helping to disseminate information to others. In line with
the foregoing, it is hereby suggested that individually and
collectively we must ensure that we
Ÿ
Replenish whatever we take away from the soil
Ÿ
Keep the soil always vegetated rather than leaving it
bare
Ÿ
Avoid bush burning
Ÿ
Plant at least two trees for every one cut down
Ÿ
Integrate NF-legumes (grains, green manure and
woody ones) into existing cropping systems
References
Giller, K.E. (2001).Nitrogen Fixation in Tropical Cropping
Systems, 2nd Edition. CABI Publishing, Wallingford, UK, 423 pp.
Kang, B.T., Reynolds, L. and Atta-Krah, A.N. (1990) Alley
Farming. Advances in Agronomy 43, 315 – 359.
Koch, A., McBratney, A. and Lal, R. (2012) 'Global Soil Week:
Put Soil Security on the Global Agenda', Nature 492, p. 186.
Koch, A., McBratney, A., Adams, M., Field, D., Hill, R., Crawford,
J., Minasny, B., ..... Zimmermann, M. (2013). Soil Security:
Solving the Global Soil Crisis. Global Policy. University of
Durham and John Wiley & Sons, Ltd., New York. pp. 1 – 8.
McBratney, A.B., Minasny, B., Wheeler, I. and Malone, B.P.
(2012). Frameworks for digital soil assessment. In: Minasny, B.,
Malone, B.P., McBratney, A.B. (Eds.), Digital Soil Assessment
and Beyond. Taylor & Francis Group, London, pp. 9 – 14.
McBratney, A., Field, D.J. and Koch, A. (2014). The Dimensions
of Soil Security. Geoderma 213, 201 – 213.
Osunde, A.O. and Bala, A. (2001). Biological nitrogen fixation
and farming systems in Nigeria: Problems and prospects.
African Journal of Science and Technology 1, 11-14.
WMO. (2005). Climate and Land Degradation. World
Meteorological Organization (WMO) No. 989. Geneva,
Switzerland.
The mitigation of soil degradation and the maintenance of a
secure soil should however not be left to governments alone.
Nature & Faune Volume 30, Issue No. 1
17
Pl anning, prioritizing and deployment of
appropriate soil management tools for intensive and
sustainable soil productivity.
Priorities for Sustainable Soil Management in
Nigeria
Victor Okechukwu Chude1 and Azubuike Chidowe
Odunze2
Improving access to existing knowledge and
information on sustainable land management
(SLM) and consequences of inappropriate
management.
Summary
Planning and executing sound natural resource management
at watershed and landscape levels has become increasingly
important for retaining ecological integrity and ensuring that
food and fibre systems are resilient enough to absorb shocks,
stresses and avoid land and water resources degradation.
Prioritizing and addressing desertification, land degradation
and climate change challenges in Nigeria is critical for
achieving food security and nutrition, their adaptation to
climate change, protection of biodiversity, development of
resilience of soil to natural disasters to benefit from new
scientific knowledge detailing extent and importance of
ecosystem services and their roles in sustaining human and
agro-ecosystems. In Nigeria and for agricultural purposes,
sustainable land management which combines technologies,
policies and activities aimed at integrating socioeconomic
principles with environmental concerns is advocated.
Prioritizing sustainable soil management in Nigeria requires
that land/soil degradation; a common sight in Nigeria that
continues unabated due to absence of a 'National Soil
Research Institute' with the mandate to oversee use,
sustainable management of the nations' nonrenewable
natural resource (soil) and monitoring incidence; if any, of land
degradation across the country be established. Also, most
productive agricultural lands are rapidly impoverished due to
nutrient mining by crops, soil erosion and improper soil
management practices. Integrated soil health/quality
management approaches should be prioritized and adopted
to ensure sustainable agricultural productivity, food security
and environmental conservation. Detailed soil map of Nigeria
focusing on potential agricultural productive areas should be
conducted to allow for planned sustainable intensification of
agricultural production and the attainment of national food
security
Introduction
Planning and execution of sound natural resource
management at watershed and landscape levels has become
increasingly important for retaining ecological integrity and
ensuring that food and fibre systems are resilient enough to
absorb shocks and stresses and avoid land and water
resources degradation (FRP, 2005; IBRD/World Bank, 2006).
Prioritizing and addressing desertification, land degradation
and climate change challenges will be critical for achieving
food security and nutrition, their adaptation to climate
change, protection of biodiversity and development of
resilience of soil to natural disasters to benefit from new
scientific knowledge detailing extent and importance of
ecosystem services and their roles in sustaining human and
agro-ecosystems. Therefore, investments in emerging
scientific knowledge will be necessary in:
Rehabilitating land that had been degraded for both
productive and ecosystem functions (IBRD/World
Bank, 2006).
In this discussion, priorities for sustainable soil management
in Nigeria will address the following knowledge acquisition
and deployment:
1. Nature and potentials of Nigerian soils for sustainable
agricultural production.
2. Needs and priorities for sustainable soil management
3. Institutional settings for sustainable soil management.
Discussion
Nature and potentials of Nigerian soils for sustainable
agricultural production
The major soils of Nigeria according to the World Reference
Base for Soil Resources (WRB, 2014) are: fluvisols, regosols,
gleysols, acrisols, ferrasols, alisols, lixisols, cambisols, luvisols,
nitisols, arenosols and vertisols that vary in their productivity
ratings and suitabilities for different crops and inherent
limitations.
1
Victor Okechukwu Chude.
Professor of Soil Science, President, Soil Science Society of Nigeria,
Chairman, African Soil Partnership Steering Committee, FAO/GSP Focal
Person in Nigeria,
Head Agric. Productivity Enhancement, National Programme for Food
Security 127 Adetokunbo Ademola Crescent, Wuse 2, Abuja, NIGERIA
Email: [email protected], [email protected]
Tel: (+234) 8033154400
2
Azubuike Chidowe Odunze,
Department of Soil Science/IAR, Faculty of Agriculture,
Ahmadu Bello University,
P.M.B 1044, Zaria, Nigeria.
Email: [email protected]; [email protected],
Tel: (+234) 8035722052
Nature & Faune Volume 30, Issue No. 1
18
Table 1: Productivity Potentials of Nigerian Soils
Soil Productivity
rating
High (1)
Good (2)
Medium (3)
Low (4)
Low (5)
WRB Major Soil Groups
Fluvisol, Gleysols, Regosols
Lixisols, Cambisols, Luvisols, Nitisols
Acrisols, Ferrasols, Alisols, Vertisols
Arenosols
Area
km2
% of total
area
50.4
423.6
289.2
148.8
5.52
46.45
31.72
16.32
Most soils (Table 1) in Nigeria are cultivable during rainy seasons because of their adequate depths and permeability. However
fluvisols, gleysols, regosols, luvisols lixisols, cambisols, nitisols dominate soils of Nigeria with a total land area of 474 km2 or
51.97% of the total land area and therefore present most cultivable soils in Nigeria as belonging to the medium to good
productivity class. Table 2 presents brief comments on use and management of soils in Table 1; hence, their potentials for
agricultural use in Nigeria.
Small dams and barriers dug into the earth to prevent soil degradation and to keep rain water on site. A great
example of successful sustainable land management practices.
Photo Credit: @FAO/Giulio Napolitano
Nature & Faune Volume 30, Issue No. 1
19
Table 2: Use and Management of WRB Soil Groups
World Reference Base Soil
Group
Use and Management
Fluvisols
Have good natural fertility and attractive agicrultural ly productive sites on river levees and
higher parts in marine landscapes. Paddy rice cultivation is widespread on tropical Fluvisols
with satisfactory irrigation.
Gleysols
When adequately drained it can be used for arable cropping, dairy farming and horticulture.
Liming of drained Gleysols that are high in organic matter and/or of low pH value enhances
the rate of decomposition of soil organic matter, supply of plant nutrients and improved soil
quality.
Regosols
In desert areas they have minimal agricultural significance. With rainfa ll of 500 –1000
mm/year they need irrigation forsati safctor y crop production.Their low moisture holding
capacity calls for frequent applic ations of irrigation water to solve the probl em but is rarely
economic.
Lixisols
Areas still under savannah or open woodland vegetation are widely used for low volume
grazing. Tillage and erosion contrm
oleasures
; such asterrac ing, contour ploughing,
mulching and use of cover crops help to conserve the soil. The low absolute plant nutrients
and cation retention makesrecurrent inputs of fertilizers a precondition forconti nuo us
cultivation
Generally good agricultural land used intensively. In the humid tropics , they are typically
poor in nutrients but are still richer than associated Acrisols orFerral sols , and have greater
CEC. Cambisols with groundw ater influence in alluvial plains are highly productive
Cambisols
Luvisols
Most Luvisols are fertile and suitable for a wide range of agricul utral uses. Luvisols with a
high silt content are suscp
etible to structure deterioration where tilled when wet or with
heavy machinery. Luvisols on steep slopes require erosion control measures.
Nitisols
Are among the most productive soils of humid
trop sic. Have deep, porous solum , stable
structure to permit deep rotoing and make soils quite resistant to erosion. Have goo d
workability, internal drainage and fair wath
eo
r lding
properties complemented by good
chemical (fertility) properties. They have relative ly high weathering minerals content and
surface soils may contain high organic matter; in particular under forest or tree crops.
Ferrasols
Generally have good physicalpropertie s; such as soil depth, good permeability and stable
microstructure, les s susceptible to erosion. Friable when moist, easy to work, well drained
but could be droughty because of low avai alble water stora ge capacity. Has poor chemical
fertility, scarce or asb
ent weatherable minerals and weak cation retent ion capacity.
Manuring, mulching and/oardequate
fallow periods or agroforestry practices and
prevention of soil erosion, are important management require ments.
Acrisols
Adapted rainfed and irrigatedcropping systems with careful fertilization and management
are required if seden tary farming is to be practiced . Most tree roots are conc entrated in the
humus surface horizon with only a few tap-roots extendin g down into subsoils. Rotation of
annual crops with improved pasture maintains the organic matter content.
Large areas of Vertisols in semi-arid tropics are still unused or are used only for exten siv e
grazing, wood chopping, cahrcoa l burning etc. The soil has considerable agricultural
potential, but must be well managed for sustained production. Its good chemical fertility and
occurrence on extensive level plains where reclamation and mechanical culti vatio n can be
envisaged are assets of Vertisols.
Vertisols
Arenosols
Alisols
Arenosols are commonly coarsetextured, accounting for their generally high permeability,
low water andnutrien t storage capacity. On the other hand, Arenosols offer ease of
cultivation, rooting and harvesting of root and tuber crops.
The generally unstable surface soil of cultivated Alisols makes them susceptible to erosion;
truncated soils are quite common. Toxic levels of Aluminium at shallow depth and poor
natura l soil fertility are further constraints in many Alisols. Productivity of Alisols in
subsistence agriculture is generally low.
Adapted from World Reference Base for Soil Resources (WRB, 2014).
Nature & Faune Volume 30, Issue No. 1
20
Cultivation of some soils is limited by low water holding
capacity; while others have poor permeability and weak root
penetration; e.g., Arenosols, Ferralsols and Regosols (Table 2) .
Some others are highly leached, resulting in medium to high
acidity, moderate to low cation exchange capacity and base
saturation, and low to very low organic matter content. Soil
nutrient replenishment and soil quality restoration from
organic and mineral sources is a prerequisite for continuous
cultivation of most soils in Nigeria; particularly, under intensive
production systems. Many of the soils are susceptible to
erosion due to their locations in the landscape; resulting in
gullying, relatively low organic matter content and fragile
structure. Soil degradation and attendant depressed yields
due to nutrient mining, impoverished soil quality/health,
inappropriate soil and water conservation practices are wide
spread in the country.
Conclusions
Soil degradation is widespread in Nigeria and continues
unabated due to the absence of a 'National Soil Research
Institute' with the mandate to oversee sustainable
management of the nations' nonrenewable natural resource
(soil). Integrated soil health/quality management approach
should be adopted in agricultural soil use to ensure
sustainable agricultural productivity, food security and
environmental conservation. Detailed soil map of Nigeria
focused on potentially agriculturally productive areas should
be compiled to allow for planned sustainable intensification of
agricultural production and the attainment of national food
security.
References
Forestry Research Programme (FRP, 2005). “From the
Mountain to the tap: How land use and water management
can work for the rural poor”. Report of a dissemination project
funded by the United Kingdom Department for International
Development (DFID) for the benefit of developing countries.
Forestry Research Programme, NR International Ltd, Hayle,
UK; Rowe The Printers.
Th e I n t e r n a t i o n a l B a n k f o r R e c o n s t r u c t i o n a n d
Development/The World Bank (IBRD/World Bank, 2006).
Sustainable Land Management: Challenges, Opportunities
and Trade-offs. Washington DC 20433 P112
World Reference Base for Soil Resources (WRB, 2014). The
International Soil Classification System for naming Soils and
creating legends for soil maps. World Soil Resources Report
106. Published by Global Soil Partnership, International Union
of Soil Science and Food and Agriculture Organization (FAO)
of United Nations Rome. P 191
Nature & Faune Volume 30, Issue No. 1
21
National priorities for sustainable soil
management in Gambia
Abdou Rahman Jobe1
Summary
The Gambia is believed to be one of the Sub-Saharan African
countries most seriously affected by land degradation.
Current levels of land degradation have significant economic
costs for the country. The need for sustained efforts at
addressing the degradation problem through promoting and
scaling up of Sustainable Soil/Land Management activities in
The Gambia, therefore, remains relevant. In an effort to deal
with the situation, a number of projects on land management
are being or have been implemented with varying levels of
successes achieved and useful lessons learnt. The situation
can further be salvaged through a coordinated national and
international investment effort and funding mechanisms.
Partnerships involving a broad range of government and nongovernment stakeholders, including the public and private
sector, bilateral and multilateral development agencies, and
foundations can play a major role in sustaining Sustainable
Soil Management (SSM) implementation in The Gambia.
Furthermore, mainstreaming the concepts and principles of
SSM into national economic development and sectorial
policies/strategies of the government and other development
and technical institutions would serve as a catalyst towards
attainment of sustainable soil/land management which
eventually will contribute to environmentally sound food selfsufficiency and security in the country.
Introduction
Land resources, including soils, are basic resources of
agricultural production for food and markets. Their proper
management is fundamental to enhancing the capacity
and output of the sector, especially to meet macroeconomic priorities of poverty reduction and economic
growth. “The soil resources in the Gambia are fragile and
not renewable, possessing relatively low fertility, taking into
consideration the country's geo-physical location in the semiarid to arid zone of West Africa, with a drought prone ecology.
Current farming practices (crops and livestock) have not
been helpful to prevent the depletion of the already limited
fertility of the soil resources, especially their continuous use
without soil cover, poor soil fertility management, and
injudicious mechanization with tractor powered
implements”. (Ministry of Agriculture- Gambia. July 2009.
Agriculture and Natural Resource Policy 2009-2015)
The Gambia's agricultural sector consists of four sub-sectors,
namely (i) crops, (ii) livestock and poultry, (iii) research and
development and, (iv) agricultural service providers.
Agriculture is predominantly subsistence, using very little
mechanization and inputs, and rain-fed, with very little
irrigation. As such, the agricultural productivity is low, and the
sector is especially vulnerable to droughts.
The need for sustained efforts at addressing the degradation
problem through promoting and improvement of sustainable
soil/land management activities in The Gambia, therefore, is
important. However, it is recognized that the cost of
implementing SLM activities over a large area is huge and
cannot be easily borne by one institution or country. Yet,
without such interventions, the expected achievements of
enhanced livelihoods of many of the smallholder farmers who
feed the nation will be an illusion and the country's socioeconomic development as well as both human and
environmental health will be adversely affected.
Recognizing the challenges faced by the agriculture and
natural resources (ANR) sector, The Gambia's government in
1996 prepared Vision 2020 to transform the country into a
middle-income, export-oriented nation by 2020, with the ANR
sector as top priority. A series of policies, programs and
strategies were then developed to improve the ANR sector's
performance. In addition, a number of international donorfunded projects focusing on sustainable soil management
have been or are being implemented.
Land use and degradation
The Gambia has a total land area of about 1.04 million ha, of
which 558,000 hectares (or 54 percent) are arable. About
69,100 farm households cultivate 320,000 ha or 57 percent of
the total arable land. Thirty percent (96,000 ha) of the
cultivated area is devoted to groundnut production, while
coarse grains, and rice production account for 144,000 ha
(45%) and 72,000 ha (23%), respectively”. (Ministry of
Agriculture, Gambia. January 2015. The Gambia Sustainable
Land Management Investment Framework 2016 – 2020).
Only about 57 % of the total arable land being put under
cultivation is mainly attributed to the reason that the traditional
farming population is ageing and can no longer effectively
continue farming. The active young populations are not
interested in farming but in white-collar jobs around the urban
areas or in travelling to the west in search of so-called greener
pastures. However, the government has already put
strategies in place to reverse this trend, although the
emphasis is more on productivity per unit area of land than
t o t a l l a n d p u t u n d e r c u l t i v a t i o n . Th e N a t i o n a l
Entrepreneurship Development Initiative (NEDI) and the
National Youth Service Scheme (NYSS) are initiatives
introduced by government to motivate and incentivize youths
to partake in agriculture. The Gambia is believed to be one of
the Sub-Saharan African countries most seriously affected by
land degradation.
1
Abdou Rahman Jobe
Specialist in Soil and Land Management
Director, Soil & Water Management Services Unit, Yundum
Agriculture station
Department of Agriculture, Ministry of Agriculture Gambia
Email: [email protected]
Telephone: 220-9900212
Nature & Faune Volume 30, Issue No. 1
22
Within the country, land degradation is caused by a variety of
complex inter-related degradation processes such as soil
degradation. “The Gambia's soil resources have declined in
productivity as a result of soil erosion, reduction in plant
nutrient content, and adverse changes in their biological,
chemical, physical, and hydrological properties. Water
erosion has specifically led to removal of high amounts of soil
from the uplands and depositing them in the lowlands”.
(Ministry of Agriculture, Gambia. January 2015. The Gambia
Sustainable Land Management Investment Framework 2016
– 2020).
In an effort to deal with the situation, a number of projects on
soil/land management such as the IFAD/AfDB funded
Lowland Agricultural Development Project (LADEP), Global
Environmental Facility project (GEF), Participatory Integrated
Watershed Management Project (PIWAMP), National
Agricultural Land and Water Management Development
(Nema) Project, and the Sustainable Land Management
Project (SLMP) are being or have been implemented, with
varying levels of success achieved and useful lessons learnt.
These projects have demonstrated the potential contribution
of sustained improved land use and management to poverty
reduction, enhancement of livelihoods, and the country's
development as well as the attainment of the Millennium
Development Goals (MDG).
The situation can further be salvaged through coordinated
national and international investment efforts and funding
mechanisms. Partnerships involving a broad range of
government and non-government stakeholders, including
the public and private sector, bilateral and multilateral
development agencies, and foundations can play a major
role in sustaining SLM implementation in The Gambia. The
recognition of this by the government of The Gambia, and the
fact that the funding required is in excess of its baseline
funding justify the request for additional funding for
implementation.
The Gambia's national priorities for sustainable soil
management (SSM)
The Gambia's national priorities towards achieving
sustainable soil management are:
Ÿ
Sustained efforts at addressing the degradation
problem through promoting and scaling up
Ÿ
Capacity Building for SSM at all Levels: Efforts
aimed at SSM in the country will not succeed if
there is no capacity on the ground to implement
the initiatives, no matter how well-thought out
they are.
Ÿ
Assessment of the human resources and
institutional environment at all levels (national
and decentralized) to determine their readiness
for supporting SSM interventions.
Ÿ
Development of effective SSM knowledge
generation and management, Monitoring and
Evaluation (M&E) and information dissemination
systems.
Ÿ
Collection of high quality soil data to serve as
basis for land suitability evaluation, land use
planning and sustainable soil management. The
fact that much of the available data is outdated is
a constraint and there is a need for updating the
1976 national land resources study.
Ÿ
Development of new soil/natural resources and
development policies.
Ÿ
Support for knowledge sharing and innovation
networks. This will support knowledge and
innovation networks as well as sharing
experiences within The Gambia and with other
Sub-Saharan Africa countries. It will also support
networking with other regional and international
SSM and land administration networks and
programs.
Ÿ
Provision and acquisition of adequate modern
soil testing materials and equipment, ranging
from field and laboratory testing to digital map
production equipment and material.
Conclusions
The Gambia is one of the Sub-Saharan African countries most
seriously affected by land degradation, caused by a variety of
complex interrelated degradation processes, including
various types of soil degradation. Soil resources have
declined in productivity as a result of soil erosion, reduction in
soil nutrient content and adverse changes in their biological,
chemical, physical, and hydrological properties. Water
erosion has specifically led to removal of high amounts of soil
from the uplands and depositing them in the lowlands.
Therefore, mainstreaming the concepts and principles of
SSM into national economic development and sectorial
policies/strategies of the government and other development
and technical institutions would serve as a catalyst towards
attainment of sustainable soil/land management which
eventually will contribute to environmentally sound food selfsufficiency and security in the country and the continent of
Africa as a whole.
References
Ministry of Agriculture, Gambia. January 2015. The Gambia
Sustainable Land Management Investment Framework 2016
– 2020. (Unpublished) Pages 21, 28, 29, 30, 40, 58, 69
Ministry of Agriculture, Gambia. July 2009. Agriculture and
Natural Resource Policy 2009-2015. (Unpublished) Page 45
Nature & Faune Volume 30, Issue No. 1
23
Priorities for sustainable soil management in
Ghana
1
Francis M. Tetteh and Enoch Boateng
2
Summary
Low soil fertility, nutrient mining, soil erosion leading to
degradation and low use of fertilizers have contributed to low
crop yields in Ghana. The maintenance, restoration and
enhancement of soil health have been widely acknowledged
as key elements in increasing agricultural growth and
sustainable agricultural systems. Regulations to ensure supply
and quality control of fertilizer will further contribute to the
development of the fertilizer market in Ghana. Site specific and
profitable fertilizer recommendations will be required to
improve soil and crop productivity instead of current blanket
recommendations in use irrespective of soil type, crop and
environmental condition. The use of mobile soil test kits is a
way of evaluating farmers' fields for rapid site specific soil
management recommendations. The Ghana Soil Information
Service (GhaSIS) project is designed to produce soil maps and
other products for farmers to improve soil and crop
productivity. Artisanal mining is a key agent for rapid soil and
environmental degradation in Ghana. The cost of
environmental degradation and negative impact on human
health outweigh all other benefits.
Introduction
Agriculture in Ghana is faced with declining crop yields due to
nutrient mining and erosion leading to soil degradation,
weakened ability to maintain fertility and poor soil health.This
is evident from huge yield gaps (FAO, 1995).
The main goal of government policy is to improve and sustain
soil and crop productivity in order to reduce hunger and
poverty and improve livelihoods of the citizenry. To achieve
this goal the main activities being implemented are:
1. Development of soil health policies to address issues that
can result in immediate and significant growth in
productivity and livelihood of the small holder farmers by:
Ÿ
Promotion of fertilizer use,
Ÿ
Sensitizing stakeholders on regulations for
implementing the fertilizer law (control of fertilizer
quality, standards in warehousing, haulage,
distribution of fertilizer, etc),
2. Developing and providing appropriate
recommendations for various crops.
Discussion
Promotion of fertilizer use
Fertilizer use rate in Ghana is very disappointingly low (less
-1
than 12 kg ha ) (MoFA- CSD, 2012)) while nutrient depletion
rates range from about 40 to 60 kg of nitrogen, phosphorus,
and potassium (NPK) ha-1 yr-1 (FAO, 2005), being among the
highest in Africa. The target is to increase application rate to at
least 50 kg ha-1, as recommended in the Medium Term
Agricultural Sector Investment Programme (METASIP), the
policy document of the Ministry of Food and Agriculture.
Fertilizer subsidies were introduced to promote fertilizer use
and improve crop productivity of smallholder farmers.
Farmers were encouraged to use the fertilizers on mainly the
key food crops – maize, rice, millet and sorghum.
Implementation of fertilizer regulations (quality control,
storage, haulage, misleading claims, short weights)
The Fertilizer Act has the purpose to regulate and monitor the
production, importation and commercial transaction on
fertilizers and related matters. This new law provides the
foundation for the development of the fertilizer sector.
Effective implementation of the regulations will also require
sensitizing all stakeholders, including agricultural
parliamentary committees, law enforcement agencies,
farmers, etc., about the law and the regulations. The
Government of Ghana therefore needs support to implement
the regulations through sensitization of all stakeholders
including parliamentarians and law enforcement agencies on
the law and regulations.
Developing and providing appropriate fertilizer
recommendations
A key limitation to farmer's use of fertilizer in Ghana is lack of
appropriate fertilizer recommendations that could result in
high yields and good profits for farmers. The OFRA
(Optimizing Fertilizer Recommendation for Africa) project is to
help improve efficiency and profitability in fertilizer use in
Ghana within the framework of Integrated Soil Fertility
Management (ISFM) practices under smallholder farming.
The use of organic and inorganic fertilizer normally increases
crop yields, when they are applied together especially, when
the right fertilizer is applied, at the right time, right rate, in the
right place and using he right method (Vanlauwe et. al. 2011 ).
1
Francis M. Tetteh,
Soil Science Society of Ghana, CSIR-Soil Research Institute, Academy
Post Office, Kwadaso-Kumasi. Ghana
Email: [email protected]
fertilizer
3. Digital detailed soil mapping
2
Enoch Boateng,
Soil Science Society of Ghana, CSIR-Soil Research Institute, Academy
Post Office, Kwadaso-Kumasi. Ghana.
Email: . [email protected]
4. Stemming land degradation caused by artisana or
subsistence mining
Nature & Faune Volume 30, Issue No. 1
24
In order to evaluate the fertility status of soils and address the
issue of site specific fertilizer recommendation, the
International Fertilizer Development Centre (IFDC), in
collaboration with Alliance for a Green Revolution in Africa
(AGRA), is creating awareness of and promoting the use of
portable soil test kits in improving soil fertility management.
The programme is targeting soil fertility specialists, extension
agents, fertilizer companies, input dealers and farmer based
organizations as stakeholders. The use of soil test kits can
provide quick assessment of the fertility of soils that can guide
fertilizer
Digital detailed soil mapping (AfSIS, Global Soil
Partnership)
The Ghana Soil Information Service (GhaSIS) which is an
offshoot from the African Soil Information Service (AfSIS), is
designed to meet stakeholder soil information needs, and
assist with co-developing the databases, information
products and services that will be most useful in managing
soils, crops and landscapes appropriately. Some of the
products and services envisaged are a soil fertility map,
textural map, available moisture map, soil organic carbon
map, crop suitability map, yield gap map, etc. Funds are,
however, inadequate to implement the project fully.
Land degradation due to artisanal and small-scale (ASM)
mining
In 2010, artisanal gold production rose to 23% with over 60%
of the Ghanaian mining labour force directly dependent on it
for their livelihood (Hilson, 2001). Artisanal mining is an activity
that impacts on livelihood. Many factors like human health,
pollution of drinking water, accelerated soil erosion, siltation
of water bodies and irreversible destruction of agricultural
lands outweigh the poverty reduction potential of ASM in the
medium to long term. Government and artisanal miners
should seek funds for rehabilitation and re-vegetation of the
degraded soils. It takes about 100 to 1000 years to form 1 cm
of soil depending on where you are.
Conclusion
Agricultural productivity in Ghana remains low due to low use
and high cost of fertilizer, and low adoption of ISFM practices.
The GhaSIS project has been designed to provide information
and services based on diagnostic methods that use infrared
spectroscopy and remote sensing to produce soil maps and
other service products that are farmer friendly. There is the
need to promote the use of mobile soil test kits for extension
services and farmers. Sustainable management of the soil,
water, and forest resources is required to arrest or stem the
current pace of soil and environmental degradation in Ghana.
References
FAO, 2005. Fertilizer use by crop in Ghana. Rome. Pp.39
MoFA, 2009. Agriculture sector plan (2009-2015). 1st Draft. Pp.
68.
Vanlauwe, B.A.,Chianu J., Giller, K.E., Merckx, R. and
Mokwunye, U. 2011. Integrated soil fertility management :
Operational definition and consequences for implementation
and dissemination. Outlook on Agriculture. 39(1) 17-24.
Nature & Faune Volume 30, Issue No. 1
25
Strategies towards sustainable soil
management in Cabo Verde: environmental
and livelihood challenges
Isaurinda Baptista1
Summary
Soil degradation has seriously affected both people's
livelihood and the environment in Cabo Verde, a country
where only 10% of its reduced surface is arable land. To hold
the soil in place, the water in the soil, maintain sustainable
yields and combat land degradation, the governments have
implemented a number of soil and water conservation (SWC)
measures that are strikingly visible throughout the landscape.
Notwithstanding the enormous efforts and the recognition of
their benefits, a clear overview of their biophysical and
socioeconomic impacts have been poorly assessed and
scientifically documented. This paper presents an overview of
the implemented strategies towards building resilience
against the harsh environment, the state of soil degradation
and its drivers, the existing SWC measures, and the
recommended priorities for sustainable soil management in
the country. Literature review, field assessments and expert
judgment comprise the basis of this overview. Cabo Verde has
faced its limitations with relative success by implementing an
integrated governance strategy that involves awareness
raising, institutional framework development, financial
resource allocation, capacity building, and active participation
of rural communities. However, with the limited soil resources
still facing severe threats, it is crucial to implement SSM as the
key to a more sustainable agriculture, food security and
healthy soils.
Introduction
In Cabo Verde a combination of factors have resulted in
extensive soil degradation, with negative consequences for
the livelihood of the population and its fragile environment.
The stabilization of the agricultural landscape with erosion
control measures and the maintenance of sustainable yields
became priorities for the country's' governments, both as
environmental protection and survival of the population. The
successive governments have focused their rural
development policies on soil and water conservation (SWC)
strategies to address desertification, water scarcity, and soil
erosion, which have completely changed the landscape
(Ferreira et al. 2013; Baptista et al. 2015a).
Efforts to reverse and prevent land and soil degradation focus
on the concept of sustainable land management (SLM) and
sustainable soil management (SSM), referring to the use of
land or soil resources to meet present needs without
compromising the ability of future generations to meet their
own needs (Liniger et al, 2011). It includes the implementation
of agronomic, vegetative, structural, and management
measures to control soil and land degradation and enhance
productivity (Schwilch, et al, 2012). As such, the SWC
strategies implemented in Cabo Verde promote the SLM/SSM
concept, often used interchangeably in this paper.
Investments in SLM measures are enormous at the national
level, yet a clear overview of their extent and combined
benefits on agricultural productivity, conservation
effectiveness, sustainability, and livelihood, is still deficient
(Baptista et al., 2015a).
This paper aims to present an overview of the implemented
strategies towards building resilience against the harsh
environment, the state of soil degradation and its drivers, the
existing SWC measures, and the recommended priorities for
SSM in the country.
Government initiatives to reverse harsh conditions
Throughout the history, Cabo Verde has experienced
numerous events of crop failure and food insecurity that
caused extensive starvation from the 16th to the 19th centuries,
registering several famine episodes (Ferreira et al., 2013). To
eradicate famine, governments had to provide work for
people locally on the so-called FAIMO (High Intensity Labor
Fronts), which was a national program that ensured jobs for
thousands of people in rural areas, channeling the labor to the
implementation of SWC measures.
The post-independence governments, facing successive dry
years in the late 1970s and early 1980s, oriented their rural
environmental actions towards combating desertification and
soil degradation by elaborating strategic instruments,
creating proper institutional frameworks, raising awareness,
managing scarce financial resources, promoting effective
stakeholder participation, setting policies and regulations and
adhering to regional and international agreements. Because
of these initiatives, Cabo Verde is currently recognized as a
success case on transforming a harsh environment into a less
hostile living environment and building resilience to absorb
shocks from extreme drought periods, which no longer result
in food crises and starvation.
Drivers of soil degradation and major soil threats
Climatic. Extended droughts have reduced vegetation cover,
exposing bare soil to erosion, while heavy rainfall events
during the wet season generate high rates of runoff,
transporting enormous quantities of soil, seriously affects the
quality of the environment, food security, sustainability and
longevity of the limited arable land in the country. Water
erosion and related nutrient losses constitute major threats to
soil degradation in the country (Baptista et al, 2015b).
1
Isaurinda Baptista,
Researcher in Land management techniques
Instituto Nacional de Investigação e Desenvolvimento Agrário (INIDA),
CP 84 Praia, Cabo Verde
E-mail: [email protected]; [email protected];
[email protected]
Tel.: (238) 9938308 or (238) 2711127; Fax: (238) 2711133
Nature & Faune Volume 30, Issue No. 1
26
Human. Human activity exerts strong pressure on the limited soil resources, contributing to soil degradation in several ways.
These comprise: (1) Inappropriate agricultural practices such as intensive cultivation of steep slopes without adequate
conservation measures and excessive weeding with hoe, (2) overexploitation of aquifers, resulting in salinization of soil in the
valleys, (3) rural poverty, leading to deforestation due to tree cuttings for domestic use, (4) overgrazing and (5)
impermeabilization of good agricultural soils by urbanization and road construction.
Topographic and pedological. Elevation strongly influences rainfall, with highest erosivity values at high elevations, coinciding
with high rainfall, steep slopes and shallow soils, which make these areas susceptible to erosion (Figure 1).
Figure 1. Main drivers of soil degradation: (a) burning of crop residue on field, (b and c) gully erosion due to cultivation of steep
slopes with no protection, (d) gives an example of runoff loaded with sediment.
Soil fertility loss. Despite the high natural fertility of the soils,
intensive cultivation without adequate replenishment of soil
nutrients through organic or inorganic fertilizers has resulted
in the decline of soil fertility, particularly, in the dryland areas,
where the only source of nutrients for maize crops comes from
intercropped beans. The soil organic matter and carbon
content is low (< 2%) due to lack of soil cover, removal of crop
residue from farmlands and high rate of organic matter
decomposition.
State of soil resources and management
2
Land use. Of the 4033 km of land surface that the country
comprises, about 10% (41,000 ha) is cultivated. The soils are
mainly Regosols and Cambisols (WRB, 2014), i.e. soils with
limited profile development, of volcanic origin, medium to
coarse textured, steep, low in organic matter and generally
shallow. Fertile soils (i.e. Kastanozems) are present on ancient
surfaces. Soils of alluvial and colluvial origin are found in
valleys, constituting the major areas for irrigated agriculture.
Of the cultivated surface, >90% is used for rainfed agriculture
while about 6.5% is used for irrigated agriculture. About 23% of
the country's surface is forested.
Magnitude of soil erosion. Numerous efforts have been
made to quantify erosion in the country both at plot
(Smolikowski et al., 2001; Baptista et al, 2015b) and subwatershed levels (Tavares, 2010), with results indicating great
spatial and temporal variability depending on slope, land-use,
rainfall amount and intensity. Mean erosion rates for traditional
farming vary from 0.2 to 23 t/ha/yr at plot level and from 0.1 to
43 t/ha/yr at sub-watershed level. The smaller rates at plot
level correspond to low slope areas and the larger to the
steeper slopes. The large variability within results, the high
rates of erosion and shallow soils on steep terrain require
longer-term assessments to establish standard tolerable rates
for Cabo Verde hillsides, allowing policy makers to better plan
soil management interventions.
Nature & Faune Volume 30, Issue No. 1
27
Existing conservation measures. Both structural and biological SWC measures were implemented, aiming to hold the soil in
place, the water in the soil and to combat desertification. Structural techniques comprise check dams, contour rock walls,
contour furrows, micro catchments, terraces and retaining dams. Biological measures consist of vegetation barriers with
different species (i.e., Aloe vera, Leucaena leucocephala, F. gigantean), pigeon pea cultivation and reforestation with droughttolerant species. Vegetative measures, including tree/shrub cover, implemented to protect the steep hillsides, are most
widespread, reaching more than 80% surface cover in some watersheds. The implementation of SWC techniques modifies
landscape functions at different spatial scales and they have produced dramatic changes both at plot and watershed scales.
Figure 2 illustrates some soil conservation measures in the country, some of which (i.e., afforestation and Aloe vera hedges) have
been documented as successful conservation measures (Liniger et al., 2011).
Figure 2. Vegetation and structural soil conservation measures in Cabo Verde: (a) terraces for irrigated agriculture, (b) contour
rock walls, (c) afforestation in humid zone, (d) Leucaena leucocephala hedges,
(e) check dams on water ways,(f) Aloe Vera hedges
Monitoring and assessment (M&A) of sustainable soil management measures in Cabo Verde are still deficient. Recently, the
implementation of the bottom-up approach project - DESIRE (Desertification Mitigation and Remediation of Land) contributed
to fill part of the M&A gap for the Ribeira Seca Watershed , giving policy makers and implementing institutions a spatial overview
of past and ongoing processes to allow planning of future activities. DESIRE developed an approach for establishing SLM
strategies in response to desertification, consisting of five steps: (1) establishing land degradation and SLM context and
sustainability goals with stakeholders; (2) identifying, evaluating and selecting SLM strategies with stakeholders; (3) trialing and
monitoring SLM strategies; (4) up-scaling SLM strategies; and (5) disseminating the knowledge gathered (Schwilch et al., 2012).
Successful SSM requires an effective monitoring system.
Nature & Faune Volume 30, Issue No. 1
28
Priorities for sustainable soil management
The priorities to promote SSM should focus on the
implementation of the following actions:
Ÿ Establishment of a harmonized soil information system
or database;
Ÿ Assessment, monitoring and mapping of soil resources;
Ÿ Implementation and maintenance of soil conservation
techniques, including afforestation and vegetation
barriers in dryland;
Ÿ Research and adoption of SSM practices that promote
soil cover, moisture retention and nutrient uptake such
as integrated soil fertility and conservation agriculture
systems;
Ÿ Awareness raising and participation of stakeholders
through: (1) sensibilization of farmers, civil society,
NGO's and rural communities for the importance of
SSM, (2) Involvement of end-users in targeted soil
research and in finding solutions for local problems, (3)
multidisciplinary approach for identifying, prioritizing,
testing, evaluating and implementing appropriate SSM
techniques and tools to inform decision makers, and (4)
scientific and community based approaches that
promote integrated actions; and
Ÿ Increasing capacity building of research in soil
degradation and SSM through: training of researchers,
equipment of laboratories, development of targeted soil
research, including best SSM practices, assessment of
erosion, fertility management.
Policy recommendation and conclusion
In Cabo Verde, all the efforts in soil and water conservation
measures aim to improve land management as a whole, while
nowadays, there is also a need to address the soil as a limited
and threatened resource to restore its productive potential,
enabling food security. This calls for a concerted approach
between stakeholders and the scientific community, similarly
to the DESIRE approach, which could be up-scaled to the
National level and integrated into long-term programs.
With the limited soil resources facing severe threats, it is
crucial to implement SSM as the key to a more sustainable
agriculture, food security and healthy soils. Unless authorities
take serious priority actions to reverse the soil degradation
process, soil degradation neutrality may be an unrealistic goal
to attain in Cabo Verde and sub-Saharan Africa, in the near
future.
References
Baptista I, Fleskens L, Ritsema CJ, Querido A, Ferreira AD,
Tavares J, Gomes S, Reis A, Varela A. (2015a). Soil and water
conservation strategies in Cabo Verde and their impacts on
livelihoods: an overview from the Ribeira Seca Watershed.
Land 4: 22-44.
Baptista I, Ritsema CJ, Querido A, Ferreira ADF, Geissen V.
(2015b). Improving rainwater-use in Cabo Verde drylands by
reducing runoff and erosion. Geoderma 237–238: 283–297.
Ferreira ADF, Tavares J, Baptista I, Coelho COA, Reis A, Varela
L, Bentub J. (2013). Efficiency of overland and erosion
mitigation techniques at Ribeira Seca, Santiago Island, Cabo
Verde. In Overland Flow and Surface Runoff; Hydrological
Science and Engineering Book Series; Wong, T.S.W., Ed.;
Nova Science Publishers, Inc.: Singapore, pp. 113–135
Liniger HP, Mekdaschi SR, Hauert C, Gurtner M.
(2011).Sustainable Land Management in
Practice—Guidelines and Best Practices for Sub-Saharan
Africa; TerrAfrica: World Overview of Conservation
Approaches and Technologies (WOCAT): Berne, Switzerland;
Food and Agriculture Organization of the United Nations
(FAO): Rome, Italy
Schwilch, G, Hessel R, Verzandvoort S, Eds. (2012). Desire for
Greener Land. Options for Sustainable Land Management in
Drylands; Centre for Development and Environment,
University of Bern (CDE): Bern, Switzerland; ALTERRAWageningen UR, World Soil Information (ISRIC) and
Technical Centre for Agriculture and Rural Cooperation
(CTA): Wageningen, the Netherlands.
Smolikowski B, Puig H, Roose E. (2001). Influence of soil
protection techniques on runoff, erosion and plant
production on semi-arid hillsides of Cabo Verde. Agric.
Ecosyst. Environ. 87: 67–80.
Tavares, J. (2010). Soil erosion in Cabo Verde: A Study of
Processes and Quantification at the Scale of Three
Watersheds of the Santiago Island. Ph.D. Thesis, Bourgogne
University, Dijon, France.
Nature & Faune Volume 30, Issue No. 1
29
Sustainable soil management in Niger:
constraints, challenges, opportunities and
priorities
Addam Kiari Saidou1 and Aboubacar Ichaou2
Summary
Soil degradation is a significant contributing factor to low
agricultural productivity, poverty, and other social and
environmental issues in Niger. Many Nigeriens view land
degradation as one of the main causes of poverty and
vulnerability, along with population growth and drought. Soil
fertility depletion and soil erosion are also major problems in
both croplands and rangelands, resulting from the low and
declining use of fertilizers, the lack of fallow, the expansion of
farms into marginal lands, overgrazing of rangelands,
deforestation, droughts, land tenure insecurity, violent winds
that lead to highly erosive torrential rains, and other factors of
natural resources fragility. Sustainable Soil Management
(SSM) is one of the priorities in Niger. Therefore, the
importance given to land degradation through this brief SSM
paper is to be considered in light of increasing awareness for
public and private financing. In this context, guidance in
improving the effectiveness of sustainable land management
(SLM) investments is critical.
This orientation paper mainly targets natural resource
management (NRM) activities as one component that will
regenerate land and water resources. It addresses the status of
soils, their constraints and potentials and identifies priorities
and awareness measures.
Introduction
Niger is a large Sahelo-Sudanian country with a surface area
of 1,267,000 square kilometers and about 17 million
inhabitants. The country is bordered in the North by Libya and
Algeria, in the East by Chad, in the South by Nigeria and Benin,
and in the West by Burkina Faso and Mali.
Niger has experienced a series of food crises (1973, 1984,
2001, 2005, 2010), which reveal a number of drivers of which
the most important are: the tendency for the climate to dry up
and the high population growth (3.3%), which exceeds
agricultural growth (estimated at 2.5%), thus leading to an
increasing pressure on the environment. The combination of
all these factors inevitably leads to a change in ecological
balances and to land degradation. This has resulted in the
abusive exploitation of lands, often beyond the actual
capacity of ecosystems and has led to considerable loss of
their productive potential. The maintenance of these fragile
ecosystems is, however, indispensable for conducting all the
socio-economic activities of rural populations. Rural
economy constitutes the main livelihood leverage of rural
populations through agriculture, livestock, fisheries and
forestry (Ichaou and Maisharou, 2013).
The land degradation induced by ecosystem changes
generates considerable losses in terms of agricultural
income. As is the case for most sub-Saharan countries of the
circum-Sahara, Niger is ravaged by significant desertification
and land degradation phenomena which impart poverty
among populations, especially those living in rural areas. The
degradation is manifested mainly in the formation of large
bare areas that promote water erosion; the formation and
enlargement of gullies, often on cultivated land; the formation
of moving sand dunes which is one of the most acute land
degradation issues, especially in the eastern part of the
country; the sanding up of crop lands, water bodies,
agricultural production basins and various socio-economic
infrastructures (roads, houses, etc.); salinization of irrigated
farmland; leaching of nutrients; soil crusting; the reduction of
plant cover and the loss of biodiversity.
The effects of this degradation and its various forms translate
naturally into the disorganization of production systems, the
decline in rural productions (notably agriculture, livestock and
forestry); the drop in households' income and the persistence
of food insecurity.
To overcome this situation, Niger has for the past two decades
adopted measures for the conservation of soil and water and
to promote natural regeneration with the help of technical and
financial partners. This has enabled the country to acquire the
needed experience in Sustainable Land and Water
Management (SLWM). Unfortunately, despite this
accumulated experience, the phenomenon of land and
landscape degradation is steadily worsening under the effect
of climate change and human pressure, thus compromising
the various efforts made. Hence, the development of best
practices in the area of SLWM is necessary.
Among the best practices identified in Niger, this paper
presents those that have the potential of protecting farm and
pastoral land and strengthening the resilience of biophysical
systems.
1
Specialist in Soil Microbiology/Fertility,
Head of Natural Resources Management Department (DGRN),
National Institute of Agricultural Research of Niger (INRAN),
Niamey, Niger.
E-mail: [email protected]
2
Aboubacar ICHAOU Phyto-Ecologue DG INRAN BP 429
Niamey NIGER.
Tél Cel 1 : 00 (227) 96 57 21 19
Tél Cel 2 : 00 (227) 94 93 80 68 and
Email: [email protected]
Nature & Faune Volume 30, Issue No. 1
30
regard to (i) capable human resources and (ii)
appropriate equipment
Soil status
Soils are heterogeneous and need an integrated system to
manage their fertility. Meanwhile fertilizers are expensive and
often unavailable. Most soils have low fertility and with poor
cultural practices these soils are plagued by losses of
nutrients through the removal of crop residues. Soils are
especially poor in phosphorus and nitrogen. In many parts of
Niger, even virgin or fallow lands are poor in P and N (Henao
and Baanante, 2006), contributing to low soil productivity.
Large agro-ecological zones, constraints and
challenges related to fertility, degradation and soil and
water conservation
The climate in Niger is characterized by two main seasons: a
long dry season that lasts about eight months and a fourmonth rainy season starting in May or June in the Southern
part of the country. Between the Saharan, Sahelian and
Sudanian zones, rainfall varies from 0 to over 700 mm
annually. The Sudanian zone in the south covers only 1% of
the territory. Over the past 30 years, isohyets have significantly
moved towards the south under the effect of seemingly longterm climate changes. Meanwhile, due to demographic
pressure, farmlands have extended towards the north, into
lands that are always more prone to erosion.
Most of the soils used in rainfed cropping are ferruginous
tropical soils and sub-arid brown soils. Their sand content
varies between 80 and 90% and their clay content between 1
and 8%, with a low silt content of between 2 to 6%. Their water
retention capacity is very low, with a field capacity of between
5 and 12%. They are generally acidic, with a pH (Water)
varying between 4.5 to 7, and poor in organic matter (0.15 to
0.7%), and are phosphorus (0.4 to 9.4 mg /kg soil) and nitrogen
deficient.
Technical challenges
Taking into account the entire degraded land, choosing
appropriate techniques and species as well as selecting those
that are best adapted to specific sites, require specific
expertise. Often, a protected area is regenerated while manmade pressures on neighboring areas are exacerbated.
Priorities
The following recommendations are made to the government
or relevant authorities regarding supporting sustainable soil
management:
Ÿ
Create a conducive socio-economic and policy
environment to enable producers to invest in the soil
sector (Henao and Baanante, 2006) and sustainable
soil fertility management.
Ÿ
Create/strengthen the capacity of a soil institute in
Ÿ
Create a platform for SLM innovation and
community involvement
Ÿ
Create/strengthen extension, advisory, technical
and economic support services.
Ÿ
Create a communication plan towards the various
partners and public targets for soil science education
Ÿ
Ensure that SLM scientists are represented among
policy makers
Ÿ
Establish Farmer Field Schools and SLM
demonstration sites (Feder et al., 2004)
Best practices to overcome the issues and challenges
Food security should be the focus of sustainable soil
management. The extension of best practices is a solutions
package that should lead to resolving many problems and
overcoming challenges in the area of soil degradation and
contribute to the sustainable management of agricultural and
pastoral lands.
Over the years several highly effective indigenous soil and
water conservation practices have been developed by the
local populations in Niger and neighbouring countries in the
Sahel region, like Burkina Faso and Mali. These have been
implemented very successfully especially after the
devastating droughts of the 1970s. Badly degraded areas are
being regenerated and food security improved. The effective
sustainability of the implementation of these practices is due
to the fact that it is community driven, with communities taking
mental “ownership” of their own projects and thus being
committed to them. Government does not impose itself on the
projects, nor is descriptive, but is in the background available
in a supporting role when needed and requested. The
practices include (i) stabilization of dunes with suitable
shrubs/trees (Plate 1), (ii) stone bunds (Plate 2), (iii) sometimes
combined with mulching (Plate 3), (iv) resulting, for example,
in good sorghum production as seen on the left of Plate 4 in a
formerly bare area that looked like that on the right and in the
foreground ;(v) planting pits, called “zai” and elsewhere
“tassa”, with manure or compost applied in the pit (Plate 5) (vi)
“demi-lunes” (“halfmoons”), in which grain crops (Plate 6) or
fodder for lievstock (Plate 7) can be grown.
Nature & Faune Volume 30, Issue No. 1
31
Plate 4 : Stone bunds resulting in good sorghum growth (left)
Plate 1: Dune fixation with Euphorbia balsimefera
Plate 5: Planting pits (Zais) combined with the use of organic
matter.
Plate 2: Building stone bunds
Plate 6: Half moons planted with sorghum
Plate 3: Combining stone bunds with mulching
Plate 7 : Half moons planted with animal fodder grasses
Nature & Faune Volume 30, Issue No. 1
32
Conclusion
References
The soils in Niger are characterized by low soil fertility, poor
water holding capacities, vulnerability to soil physical
degradation, like crusting, faced with wind and water
erosion and various other challenges.
Aboubacar I, et Maisharou M. 2013. Gestion durable des
terres et des eaux, manuel de terrain pour les techniciens
du cadre d'appui-conseil aux producteurs ruraux. 35 p.
Good SSWM practices have a good potential for
strengthening the resilience of populations and
ecosystems, controlling the effects of climate change and
securing and improving the life of rural populations. They
can be applied on a larger scale and benefit thousands of
farmers and pastoralists.
The l arge participation of beneficiaries in the
implementation of these measures mobilizes the rural
population, thus reducing implementation costs and
constituting a significant investment in the productive
resources of the beneficiaries. It also promotes
sustainability. These good practices constitute an efficient
means to improve water management and reduce the
degradation of soils, vegetation and biodiversity while
increasing and stabilizing agrosylvopastoral yields. They
thus contribute to mitigating the effects of climate change
and significantly improving food security and the resilience
of rural populations to external shocks. The integration of a
sound use of natural resources in land planning promotes
land tenure security, reduces risks of conflicts and links with
communal and regional planning.
While land management is a promising solution for
countries such as Niger, it however requires a long-term
commitment. Covering sufficient areas to obtain a
significant impact not only at individual farm level, but also
on larger areas, is a multigenerational task that requires
national continuous effort on the part of governments to
organize the implementation and monitoring in SLM, their
enhancement and maintenance. Without this orientation
and external monitoring, the implementation of these
works will lose its dynamics.
Adam, T., C. Reij, T. Abdoulaye, M. Lanvanou, and G.
Tappan. 2006. Impacts des Investissements dans la
Gestion des Ressources Naturelles (GRN) au Niger:
Rapport de Synthèse. Niamey, Niger: Centre Régional
d'Enseignement Spécialisé en Agriculture.
Addam Kiari Saidou, Alhou B., Adam M., and Hassane A.
2014. Effect of compost amended with urea on crops yields
in strip cropping system millet/cowpea on sandy soil poor
in phosphorus. Research Journal of Agriculture and
Environmental sciences. Volume 1, issue 2, page 23-28.
Bationo A. 2008. Integrated Soil Fertility Management
Options for Agricultural Intensification in the SudanoSahelian Zone of West Africa, Academy Science Publishers
Feder, G., R. Murgai, and J. B. Quizon. 2004. “Sending
Farmers Back to School: The Impact of Farmer Field
Schools in Indonesia.” Review of Agricultural Economics
26: 45-62.
Henao, J., and C. Baanante. 2006. Agricultural Production
and Soil Nutrient Mining in Africa: Implications for Resource
Conservation and Policy Development. Muscle Shoals, AL,
USA: International Fertilizer Development Center.
Herrmann, S. M., A. Anyamba, and C.J. Tucker. 2005.
“Recent Trends in Vegetation Dynamicsin the African Sahel
and Their Relationship To Climate.” Global Environmental
Change 15: 394-404.
Kapoor, K., and P. Ambrosi. 2007. State and Trends of the
Carbon Market 2007. Washington, D.C.: World Bank
Institute, World Bank.
Larwanou, M., M. Abdoulaye, and C. Reij. 2006. Etude de la
Régénération Naturelle Assistée dans la Region de Zinder
(Niger). Washington, D.C. : International Ressources Group.
Nature & Faune Volume 30, Issue No. 1
33
Can Nigerian soils sustain crop production? The dilemma of a soil scientist
Scientists in Nigeria can be summarized as follows:
Fasina Abayomi Sunday1, Oluwadare David Abiodun2,
Omoju Olanrewaju Johnson3, Oluleye Anthony
Kehinde4, Ogbonnaya Uchenna Ogbonnaya5, and
Ogunleye Kayode Samuel6
Summary
The greatest threat to sustaining agricultural productivity in
Nigerian farming systems is the decline in soil productivity as a
result of continuous crop production without appropriate soil
management. This has also led to decline in per capital food
production over the last two to three decades. Information
from soil survey and research is an essential requirement for
ensuring efficient land use and sustainable soil management
practices. However, soil survey and research data are either
scarce or not available to guide sustainable use of soil. These
pedological data are fundamental in minimizing food
insecurity through appropriate use of sustainable soil
management systems. This is the dilemma confronting soil
scientists in Nigeria. This paper is an attempt to identify the
dilemma being faced by soil scientists in providing solutions to
sustainable use of Nigerian soil resources. The paper reviews
sustainable land management in Nigeria and adequate land
use planning as a prerequisite for sustainable use of land and
m a ke s a p p r o p r i a te r e c o m m e n d a t i o n s r e g a r d i n g
requirements to ensure sustainable use of Nigerian soil
resources.
Ÿ
No one listens - individuals, farmers, land users and
government care little about the misuse of land in Nigeria.
Ÿ
The above leads to unchecked misuse of land, as
reported by Fasina (1997 and 2001a), loss to erosion,
desertification and other forms of land degradation.
Ÿ
The economic sustainability being clamored for is not
related to land/soil management and thus not to
agricultural and/or environmental sustainability.
Ÿ
On the face value, the soils look productive, but they are
fragile - low activity clay (LAC) soils that have very low
inherent soil fertility and are vulnerable to degradation.
Ÿ
Nigeria has no national soil classification system and
major global systems do not enable suitable soil
classification at detailed level.
Ÿ
Nigeria has no national land suitability evaluation system.
Ÿ
Nigeria has no soil information data base that can be
used for land suitability evaluation and land use
planning.
1
Introduction
One of the major factors responsible for food insecurity in
Nigeria is poor crop yield due mainly to unfavorable soil
conditions. A large proportion (70%) of the soils in Nigeria is
made up of low activity clay (LAC) soils which cannot naturally
sustain crop production on a continuous basis (Ogunkunle,
2009). The population explosion of the last few decades has
put great pressure on the available resources resulting in soil
degradation of various types. The yields of most Nigerian
crops are low in spite of the high yielding varieties that are
being grown (Table 1). Unfortunately both the average yields
and the average yields expressed as percentage of the
potential yields of especially staple grains are very low. This
has been attributed to inherent poor soil conditions and soil
degradation. There is an urgent need for a well–planned
scientific soil management strategy to control and prevent
degradation and ensure favorable conditions for use of the
soils for increased and sustained crop production. In an
assessment of the productivity of soils in Africa, Salako (2010)
reported that Nigeria is among countries with mainly low to
medium productivity soils which can be improved with good
management. Not all lands are suitable for agriculture and the
lands that are suitable for cropping exhibit various degrees of
suitability. They may also be suitable in the short term, but not
for sustainable continuous crop production. This is where
sustainability becomes the key issue and the dilemma of the
soil scientist. The dilemmatic situations confronting the Soil
FASINA, Abayomi Sunday.
[email protected]
Department of Crop, Soil and Environmental Sciences, Faculty of
Agricultural Science, Ekiti State University, P.M.B. 5363, Ado Ekiti,
Ekiti State, Nigeria.
+23480 6036 9936.
2
OLUWADARE, David Abiodun.
[email protected]
Department of Soil Science, Faculty of Agriculture, Federal University
Oye Ekiti, P.M.B. 373, Oye Ekiti, Ekiti State, Nigeria.
+23481 6605 3500.
3
OMOJU, Olanrewaju Johnson
[email protected]
Department of Soil Science, Faculty of Agriculture, Federal University
Oye Ekiti, P.M.B. 373, Oye Ekiti, Ekiti State, Nigeria.
+23480 3524 2237.
4
OLULEYE, Anthony Kehinde
[email protected]
Department of Soil Science, Faculty of Agriculture, Federal University
Oye Ekiti, P.M.B. 373, Oye Ekiti, Ekiti State, Nigeria.
+23480 3808 9714.
5
OGBONNAYA, Uchenna Ogbonnaya
[email protected]
Department of Soil Science, Faculty of Agriculture, Federal University
Oye Ekiti, P.M.B. 373, Oye Ekiti, Ekiti State, Nigeria.
+23480 7191 9608
6
OGUNLEYE, Kayode Samuel
[email protected]
Department of Soil Science, Faculty of Agriculture, Federal University
Oye Ekiti, P.M.B. 373, Oye Ekiti, Ekiti State, Nigeria.
+23480 6136 3774
Nature & Faune Volume 30, Issue No. 1
34
Given the problem statement outlined above, the overall
objective of this paper is to discuss issues relating to
sustainable use of Nigeria's soils for sustained optimal crop
production. The specific objectives are: (1) To identify and
discuss issues on sustainable land management in Nigeria
and Africa. (2) To evaluate land use planning as a prerequisite
for sustainable use of soils. (3) To make recommendations on
how to sustain Nigeria's soil resources.
Sustainable land management in Nigeria
Nigeria, like the rest of Africa, cannot achieve sustainable food
security without sustainable land management. There have
been many definitions for sustainable land management.
Smyth and Dumanski (1995) defined it as a management
system that combines technologies, policies and activities
aimed at integrating socio-economic principles with
environmental concerns to achieve the five-fold objectives of
productivity, security, protection, viability and acceptability,
while Greenland (1994) defined it as a system that does not
degrade the soil or significantly contaminate the environment
while providing necessary support for human life. Ogunkunle
(2009) clearly stated that the different definitions differ with
the differences in the emphasis placed on factors of
management.
Some very obvious reasons have been advanced for the
need for sustainable land management in Nigeria and Africa.
Ogunkunle (2009) listed some of these reasons as:
(I)
Rapid population growth and increasing pressure
on the limited land resources.
(ii) Agricultural practices, coupled with poor
management, have been responsible for
considerable natural resource degradation.
(iii) The problem of decline in productivity and/or high
cost of food that may occur in the event that the nonrenewable resources on which production is based
runs out.
(iv) Traditional agricultural systems, some of which are
sustainable, are fast disappearing and being
replaced by farming systems that are more intensive
than vulnerable resources can tolerate and are
dependent on finite fossil fuels and off-farm
resources.
(v) The development of additional lands for agricultural
purposes requires substantial investments to
improve soil fertility, availability of water, irrigation,
drainage and erosion control. These are often also
marginal soils that are more vulnerable to
degradation.
According to the review of Junge et al. (2008) on soil
conservation in Nigeria, substantial work has been done to
develop technologies that can reverse or prevent land
degradation and sustain productivity. It indicates that there is
no agro-ecological zone in Nigeria that soil scientists and
agronomists have not covered to address issues related to
sustainable land management. Among the technologies
which have been tested are: (i) Mulching (ii) Cover cropping
(iii) Intercropping (iv) Alley- cropping (v) Ridging or Tied
ridging (vi) Conservation tillage or no tillage (vii) Planted
fallows and Natural fallows.
Experience in southwest Nigeria has shown that while the
various soil management technologies proposed by
researchers increase soil productivity adequately on
undegraded soils, it is difficult to sustain productivity of
previously degraded soils beyond one or two years with these
technologies, without a long term fallow or adequate
application of soil amendments (Shittu and Fasina, 2004;
Salako et al 2007b; Tian et al 2005). Shittu and Fasina (2004)
tested the potential of appropriate plant residue management
as a basis for sustainable maize production for two years in
Ado–Ekiti (Table 2). They observed that surface mulching
residue had a better yield potential for maize production in
Nigeria. According to their study, the only treatment with the
worst grain yield in the second year was where stubble was
removed completely through bailing, thus indicating that
removal of stubble is a non-sustainable practice. They
therefore concluded that plant residues should not be
removed in order to avoid nutrient loss and reduction in yield
of maize. The insignificant difference between the effects of
burning and non-burning of the residues indicates that the
benefit from non-removal of the residue was due to its return
of plant nutrients to the soil which could increase soil organic
matter in the long run. The result also indicated that decrease
in biomass and grain yield was due to reduction in soil organic
carbon content. This is corroborated by Pantami et al. (2010)
who reported decrease in soil organic carbon content as a
result of burning and this was attributed to oxidation of
organic carbon because most organic colloids are altered by
soil heating from 100-250oC. Studies by Ojeniyi and Adejobi
(2002) and Owolabi et al (2003) showed that higher nutrient
uptake and crop yields are benefited by succeeding crops of
bush and residue burning due to the dissolved ash which
serves as liming and fertilizing materials. However, this is
short-lived.
Nature & Faune Volume 30, Issue No. 1
35
Table 1: Average and potential yield of cereals and tuber crops in Nigeria
Crop
Average yield (t/ha)
Potential yield (t/ha)
Average yield relative
to potential yield (%)
Upland rice
0.8 - 1.2
1.5 - 2.5
50
Lowland rice
Maize
1.0 - 2.0
2.5 - 8.0
29
1.5 - 2.0
3.5 - 10.0
26
Sorghum
0.5 - 1.2
2.0 - 2.5
38
Millet
0.5 - 1.0
1.0 - 2.0
50
Cassava
11 – 12
20 – 25
51
Cocoyam
5– 6
8 – 10
61
Irish potato
10 – 12
14 – 15
76
Sweet potato
10 – 12
14 – 15
76
Yam
12 – 14
18 – 20
68
Source: Ogunkunle, 2009.
Table 2: Percent Change in Field Dried Cob Weight (t/ha) and Maize Grain Yield (t/ha) After Treatment with Different
Residue Management
Treatments
Burnt residue left on surface
Incorporation of burnt residue
Incorporation without burning
Surface mulching
Bailing
(S.E)
CV%
Field dried cob weight (t/ha)
Maize grain yield (t/ha)
2001
5.7a
5.4a
5.2a
3.9b
2001
3.2ab
3.5a
2.9b
2.5b
3.8a
6.1
(0.39)
24.3+
2002
% change
5.4
5.3
5.2
5.2
4.9
-5.2
-1.6
0
33.3
-29.6
2002 % change
3.1a
-3.1
2.7ab
-22.9
3.3a
13.8
3.4a
36.0
2.1b
-44.7
(0.36)
32+
Means for treatment over the two years having the same superscript letter are not statistically significant
Source: Shittu and Fasina 2004
Note:Negative value indicates percent reduction LSD at 5%
Figures in parentheses indicate standard error at P<0.05
(-) indicates coefficient of variability
Land use planning – a prerequisite for sustainable use
of soils
Land use planning is the process of evaluating land and
alternative patterns of land use and other physical, social and
economic conditions for the purpose of selecting and
adopting the kind of land use and courses of action best
suited to achieve specified objectives (Purnell, 1988). Land
use planning aims to make the best use of limited resources
by: (i) Assessing present and future needs and systematically
evaluating the land's ability to supply them. (ii) Identifying
sustainable alternative uses and choosing those that best
meet these needs. The goals of land use planning define what
is meant by the “best” use of land.
Optimum land use efficiency is achieved by matching
different land uses with the areas that will yield the greatest
benefits at the least cost. Fasina (1997) in a study in Lagos
State, Nigeria, recommended some plausible land use plans
for selected sites in Lagos State in line with the quality of the
soils identified within the selected area. Land use planning is
best carried out by a multi-disciplinary team, to make possible
a holistic approach to use of the land. Proper land use
planning is the basis for a sustainable land use and strong
productive agriculture. This means diagnosing land use
problems, generating viable options for tackling them and
getting information about the consequences of adopting
each option to wherever decisions about land use is being
made (Fasina 2004).
Nature & Faune Volume 30, Issue No. 1
36
In Nigeria and Africa, there is a serious problem of allocation of
land to wrong uses. Hardly is any thought ever given to the
nature of land being allocated to urban, residential and
industrial development. Lands are bulldozed for roads,
airports and vast areas acquired for residential and industrial
development, irrespective of the agricultural qualities of the
soils or the environmental impact of these uses (Fasina
2001a). Consequently scarce areas with potential cropland
are lost permanently for crop production. Fasina (2001a) and
Idachaba (1992) discussed the major constraints to land use
planning as a prerequisite for the sustainable use of soils,
including among others: (i) Lack of considering alternative
land uses and soil management frame-works. (ii) Poor data
base. (iii) Very limited improved land development and
management technologies and capacities. (iv) Generalized
fertilizer recommendations. (v) Land tenure security
problems. (vi) Problems related to abandonment of or
changes to slash and burn rotation and bush fallow
technology. (vii) Poor public perception and lack of
economic education.
It was against the background of these persistent constraints
in land use planning, sustainable soil management and the
implementation difficulties and failure of previous projects
that the National Agricultural Land Development Authority
(NALDA) was created in Nigeria to address the constraints
listed above. However, there is need to develop a national
framework for alternative land use planning and sustainable
soil management in Nigeria. The main elements pointed out
by Fasina (2013) should include: (i) A land use planning and
sustainable soil management in support of agro-ecological
specialization in production. (ii) Serious commitment to fight
deforestation and desertification. (iii) Provision of data on land
use and soil management. (iv) Generation and dissemination
of improved land development and soil management
technologies. (v) Disengagement of government from direct
involvement in fertilizer importation and distribution, since
this is not efficient.
Conclusion and recommendation
Soils in Nigeria are not as fertile as people believe. The soils
require development and implementation of special
management approaches beyond appropriate fertilizer
application, some of which have been developed, to support
food production on a continuous sustainable basis. There is
need to establish a National Soil Research Institute to handle
all issues relating to sustainable soil use and management.
Based upon the discussions above, we wish to suggest the
following recommendations which if implemented can help
sustain the Nigerian soil resources:
1.
Production of a detailed soil map for Nigeria: A high
quality detailed soil map is a prerequisite for efficient
land use planning and sustainable land use. The
federal government of Nigeria should assemble
qualified pedologists and other experts under a
national soil research institute to produce a detailed
soil map for Nigeria while providing them with every
needed logistics.
2.
Creation of awareness for the need for land use
planning and sustainable soil management in
Nigeria through general education and public
enlightenment: Both government and the Soil
Science Society of Nigeria should take leading roles
in this.
3.
Promulgation and implementation of appropriate
legislation relevant to land use and soil
conservation. This is the responsibility of
government, but should be done in consultation
with the country's soil scientists to ensure that it is
appropriate and relevant for Nigeria. On one hand,
cultivation of non-arable land should not be allowed
while on the other hand, prime and unique
agricultural land should be reserved for agriculture.
Strict appropriate soil conservation measures
should be defined and enforced, especially on
marginal land.
4.
Nigerian tertiary institutions must be strengthened
to train soil scientists who can contribute
meaningfully to continuous sustainable use of the
country's soil resources: These scientists must both
have good basic scientific soil knowledge and be
ex p o s e d to t h e s p e c i f i c p ro p e r t i e s a n d
characteristics of Nigerian soils and their
management requirements. Constant review of soil
science curricula at both undergraduate and
postgraduate levels should be done to meet the
st
requirements of 21 century sustainable land use
management.
5.
Adequate funding of soil research: Government
should shoulder the responsibility to provide
adequate funding for soil research in Nigeria on a
continuous basis. Research institutions must be well
equipped and well-staffed.
References
Fasina, A.S. (1997). Land use and land Quality in selected
Areas of Lagos State. Unpublished PhD Thesis. Department
of Agronomy, University of Ibadan, Ibadan 311P
Fasina, A.S. (2001a). Land use and land quality in Lagos State.
Annals of Agricultural Sciences. 2 (2): 74-83
Fasina, A.S. (2004). Influence of soil and management on
maize (zea mays) yield in some selected farms in Lagos State,
Nigeria Journal of Soil Science. 15:63-74
Fasina, A.S. (2013). “Can these soils sustain?” The Dilemma of
a pedologist 37th Inaugural Lecture Delivered by Professor
Abayomi Sunday Fasina at Ekiti State University on 23rd April,
2013. 76pp.
Nature & Faune Volume 30, Issue No. 1
37
Greenland, D.T. (1994). Soil Science and sustainable land
management in syers, J.K and Rimmer D.L (Eds). Soil Science
and sustainable land management in the tropics CAB
International 273pp.
Pantami, S. A., Voncir, N., Babaji, G. A. and Mustapha, S. (2010).
Effect of Burning On Soil Chemical Properties in the Dry SubHumid Savanna Zone of Nigeria. Researcher, 2 (7)
Purnell, M.F. (1988). Methodology and Techniques for land
use planning in the tropics. Soil survey and land Evaluation. 8:
9-22
Idachaba, F.S. (1992). Land use planning and soil
management for sustainable Agriculture. Keynote address
delivered at the Annual Conference of Soil Science Society of
Nigeria held at University of Ilorin on 16th November, 1992.
P21.
Salako, F.K. (2010). Development of Isoerodent maps for
Nigeria from Daily rainfall amount. Geoderma (Accepted)
Junge, B., Abaidoo, R., Chikoye, D. and Stahr, K. (2008): Soil
conservation in Nigeria. Past and present on-station and on –
farm initiatives. Soil and water conservation society Ankeny,
lowa, USA, 28pp
Salako, F.K., Dada, P.O., Adejuyigbe, C.A. and Williams, O.E.
(2007b). Soil strength and maize yield after topsoil removal
and application of nutrient amendments on a gravelly Alfisol
toposequence. Soil and Tillage Research 94: 21 - 35
Ogunkunle, A.O. (2009). Management of Nigeria soil
Resources for sustainable Agricultural productivity and food
rd
security, Proc. of the 33 Annual conference of soil science
society of Nigeria held at university of Ado – Ekiti (March 9 –
13, 2009) 9 – 24pp.
Shittu, O.S. and Fasina, A.S. (2004). Comparative effect of
different residue management on maize at Ado-Ekiti, Nigeria.
Journal of Sustainable Agriculture (USA) 28 (2): 41-54.
Ojeniyi, S.O. and Adejobi, K.B. (2002). Effect of ash and goat
dung manure on leaf nutrients composition growth and yield
of amaranthus. The Nigeria Agriculture Journal 33, 46-57.
Owolabi, O., Adeleye, A., Oladejo, B.T. and Ojeniyi, S.O. (2003).
Effect of wood ash on soil fertility and crop yield in Southwest
Nigeria. Nigerian Journal of Soil Science 13, 61-67.
Smyth, A. J. and Dumanski, J. (1995). A framework for
evaluating sustainable land management. Can. J. Soil Sci.
75:401406.
Tian, G. Kang, B.T., Kolawole, G.O. Idinoba, P. and Salako, F.K.
(2005). Long- term effects of fallow systems and lengths on
crop production and soil fertility maintenance in West Africa.
Nutrient Cycling in Agro ecosystems 7:139-150.
Nature & Faune Volume 30, Issue No. 1
38
Siltation of major rivers in Gonarezhou
national park, Zimbabwe: a conservation
perspective
Edson Gandiwa1 and Patience Zisadza-Gandiwa2
vegetation dominated by mopani (Colophospermum
mopane) woodland (Gandiwa, 2011). Three major rivers
traverse the park, namely Mwenezi River (57 km), Runde River
(77 km) and Save River (32 km) (Gandiwa et al., 2012a;
Zisadza-Gandiwa et al., 2013).
Summary
This article focuses on siltation in major rivers in the greater
Gonarezhou ecosystem, potential impacts of siltation on
wildlife conservation and options to reduce the siltation
challenge in southeast Zimbabwe. Data were collected
through field observations between 2005 and 2013, and
literature review. The results show that the three major rivers,
namely Mwenezi, Runde and Save, in Gonarezhou National
Park are highly silted. The major cause for the siltation is
attributed to land degradation due to anthropogenic activities.
Strategies to minimise siltation including integrated river basin
management and sustainable land use approaches are
suggested.
Introduction
Globally, freshwater ecosystems are under threat from
anthropogenic activity and climate change (Magadza, 1994;
Mantyka-Pringle et al., 2014; Midgley and Bond, 2015). In
particular, poor land use practices have led to increased soil
erosion resulting in siltation of major rivers (Ananda and
Herath, 2003; Kidane and Alemu, 2015). Siltation of major
rivers has negative implications on biodiversity, ecosystems,
livelihoods and economic dimensions (Dudgeon, 2000;
Schuyt, 2005). Thus, understanding the extent of siltation of
major rivers is important for developing strategies to protect
the freshwater ecosystems. Gonarezhou National Park (GNP)
in southeastern Zimbabwe has over the years witnessed
increasing siltation of its major rivers. However, long-term data
on siltation of the major rivers is not available, pointing to the
need of temporal and spatial analysis of these major rivers to
determine the historical siltation status and trends. This article
is aimed at advancing our understanding on siltation of the
major rivers, potential impacts of siltation on wildlife
conservation and suggests options to reduce the siltation
challenge in the greater Gonarezhou ecosystem.
Fig. 1. Location of Gonarezhou National Park showing major
rivers in southeast Zimbabwe. Source: Gandiwa et al. (2012b).
Data collection and analysis
Data were collected through field observations within the
greater Gonarezhou ecosystem between 2005 and 2013, and
review of published scientific literature of work conducted in
GNP. Data were qualitatively analysed and presented along
major themes related to the potential impacts of siltation on
the Gonarezhou ecosystem and wildlife conservation.
Results and discussion
Status of major rivers in Gonarezhou national park
The three major rivers in GNP, i.e., Mwenezi, Runde and Save,
are highly silted (Fig. 2). Field observations have shown that
Runde and Save rivers have continuous flow throughout the
year whereas Mwenezi River is characterised by isolated large
pools in the driest periods of the year.
Methods
Study area
This study focuses on GNP (~5,050 km2) located in the
southeastern lowveld of Zimbabwe (Fig. 1), between 21°
00'–22° 15' S and 30° 15'–32° 30' E. Established in the early
1930s as a Game Reserve, GNP was upgraded into a National
Park under the Parks and Wildlife Act of 1975. GNP is part of
the Great Limpopo Transfrontier Conservation Area into
which conservation areas in Zimbabwe, Mozambique and
South Africa have been integrated into one. The park has a
semi-arid climate with long-term annual rainfall of
approximately 466 mm and is endowed with diverse wildlife
species (Gandiwa and Zisadza, 2010) and savanna
1
Edson Gandiwa, PhD, Professor and Executive Dean, School of Wildlife,
Ecology and Conservation, Chinhoyi University of Technology, Private
Bag 7724, Chinhoyi, Zimbabwe.
Mobile: +263 773 490 202;
Email: [email protected] and [email protected]
2
Patience Zisadza-Gandiwa, MSc, International Coordinator–Greater
Mapungubwe Transfrontier Conservation Area, Transfrontier
Conservation Areas Unit, Zimbabwe Parks and Wildlife Management
Authority, P.O. Box CY 140, Causeway, Harare, Zimbabwe.
Mobile: +263 772 916 988;
Email: [email protected] and
[email protected]
Nature & Faune Volume 30, Issue No. 1
39
Fig. 2a Mwenezi River
Fig. 2b Runde River
Fig. 2c Save River
Fig. 2. Status of siltation of three major rivers in Gonarezhou
National Park, southeast Zimbabwe, September 2012. Photo
credits: P. Zisadza-Gandiwa and Gonarezhou Conservation
Project.
Causes of siltation
Siltation of the major rivers in GNP is largely caused by
upstream human activities, including poor agricultural
activities such as riverbank cultivation, lack of contours in the
agricultural fields, overstocking and consequently
overgrazing, settlement expansion, loss of vegetation cover
through uncontrolled fires, and uncontrolled removal of trees
and wetland destruction for utilization of these areas for
farming activities. Furthermore, natural processes such as
sheet erosion and weathering also contribute to the siltation of
major rivers in GNP. However, it is likely that the contribution of
the natural processes to the siltation is very small compared to
anthropogenic influences. Land degradation has been
identified as the cause of siltation and consequently reduction
of surface stream water resources (Magadza, 1984). Siltation is
also prevalent in other smaller rivers within GNP, e.g., as
witnessed by the siltation of Benji Weir, primarily from erosion
which may have been exacerbated by animal concentration
near water sources, and loss of vegetation cover from fires and
herbivory (Tafangenyasha, 1997).
Potential impacts of siltation on ecosystems and wildlife
conservation
Upstream and downstream of GNP, the three major rivers play
an important role for local people (e.g., household water
provision, gardening), agricultural production (e.g., sugarcane
plantations), water provision for livestock and economic
activities such as aquaculture. However, with increased
siltation of the three major rivers there is a direct negative
impact on the mentioned ecosystems services and/or
activities. Also, loss of soil in the adjacent communal areas
degrades the land, making it less productive and increasing
the vulnerability of local people to extreme events such as
droughts and floods. Given that the water resource is shared
with neighbouring countries, within the Great Limpopo
Transfrontier Conservation Area, it is important to enhance
integrated river basin management (Gandiwa et al., 2012a),
and reduce soil loss and river siltation for the benefit of
livelihoods and wildlife conservation in the region.
Siltation of major rivers in GNP impacts negatively on river
health as the remaining flowing water is prone to increased
pollution from upstream sugarcane plantations as silt acts as a
vehicle for certain pesticides and phosphates which affect
aquatic life downstream through nutrient loading and
reduced dissolved oxygen. The fine sediment loading in GNP
rivers smother the river bed and kill off invertebrates and fish
eggs, resulting in reduced spawning success and/or
inevitable aquatic biodiversity losses. Moreover, the reduction
in volume of water flow and also pool size has negative
implications on hippopotamus (Hippopotamus amphibius)
and crocodile (Crocodylus niloticus) populations along the
major rivers (O'Connor and Campbell, 1986; Zisadza et al.,
2010; Zisadza-Gandiwa et al., 2013). The high concentration
of wildlife species in and around remaining large pools may
lead to animals fighting for territories, e.g., hippos, with some of
the displaced animals moving to the sections of the rivers
outside the park which results in human-wildlife conflicts since
such species are regarded 'problem animals' in the area,
because they destroy crops and kill people.
Nature & Faune Volume 30, Issue No. 1
40
Other negative implications of loss of larger pools due to
siltation include reduced wildlife viewing opportunities, less
opportunities for recreational fishing, and disappearance of
species that prefer flowing water. These would have negative
economic impacts due to the area becoming less attractive
for tourists. On the other hand, remaining large pools can
easily form hotspots for illegal fish harvesting (Gandiwa et al.,
2012b) and also illegal hunting of wildlife as they concentrate
in the areas with water, especially during the dry season.
Concentration of wildlife in such spots also leads to very
serious overgrazing and increased erosion. This in turn
aggravates the siltation problem.
The reduced water flow along the major rivers has a direct
influence on wildlife species distribution and habitat
utilisation as animals commonly concentrate near the water
sources hence likely leading to localised habitat degradation
of some vegetation communities especially from elephant
(Loxodonta africana) activity (Gandiwa et al., 2011). Increased
siltation will likely have a direct impact on surface water
availability within the park as the major rivers, natural water
pans, and two weirs/dams are the main sources of water for
wildlife in GNP. The current management plan for GNP
discourages further artificial water provision within the park as
a way of encouraging the natural regulation of wildlife
populations (ZPWMA, 2011).
Loss of large pools may also impact negatively on cultural
activities such as saila (annual fish drives) where local people
gather and sustainably harvest fish in some of the largest
pools. Prospects for developing cultural tourism products
related to festivals will not materialise if the current siltation
trends are not managed. Furthermore, wildlife dispersal will
change following surface water availability and distribution. In
turn, such changes have cascading impact on sport hunting
in the adjacent communal areas under the communal areas
management programme for indigenous resources
(CAMPFIRE).
Conclusion
This article shows that the major rivers in GNP are highly silted
largely through land degradation from anthropogenic
activities upstream. Given the potential challenges that
climate change will have on the study area (Gandiwa and
Zisadza, 2010), it is thus important to be proactive on ways to
minimise siltation in the major rivers in GNP. Therefore, the
following are recommended:
Ÿ
Promoting sustainable land use management
approaches upstream of the major rivers traversing
through the park, e.g., through discouraging stream
bed cultivation and illegal artisanal mining along
rivers and their catchments;
Ÿ
Enhancing integrated river basin management;
Ÿ
Enhancing awareness campaigns and education on
ways to minimise land degradation;
Ÿ
Enhancing river health monitoring systems; and,
Ÿ
Ensuring that there is continued water flow
downstream in catchments with some dams as a way
to ensure continued ecosystem functioning within
the protected area.
References
Ananda, J. and Herath, G. (2003). Soil erosion in developing
countries: a socio-economic appraisal. Journal of
Environmental Management, 68(4): 343-353.
Dudgeon, D. (2000). Large-scale hydrological changes in
Tropical Asia: prospects for riverine biodiversity. BioScience,
50(9): 793-806.
Gandiwa, E. and Zisadza, P. (2010). Wildlife management in
Gonarezhou National Park, southeast Zimbabwe: Climate
change and implications for management. Nature & Faune,
25(1): 101-110.
Gandiwa, E. (2011). Importance of dry savanna woodlands in
rural livelihoods and wildlife conservation in southeastern
Zimbabwe. Nature & Faune, 26(1): 60-66.
Gandiwa, E., Magwati, T., Zisadza, P., Chinuwo, T. and
Tafangenyasha, C. (2011). The impact of African elephants on
Acacia tortilis woodland in northern Gonarezhou National
Park, Zimbabwe. Journal of Arid Environments, 75(9): 809814.
Gandiwa, E., Gandiwa, P., Sandram, S. and Mpofu, E. (2012a).
Towards integrated river basin management: A case study of
Gonarezhou National Park, Zimbabwe. Nature & Faune, 27(1):
70-75.
Gandiwa, E., Zisadza-Gandiwa, P., Mutandwa, M. and
Sandram, S. (2012b). An assessment of illegal fishing in
Gonarezhou National Park, Zimbabwe. E3 Journal of
Environmental Research and Management, 3(9): 0142-0145.
Kidane, D. and Alemu, B. (2015). The effect of upstream land
use practices on soil erosion and sedimentation in the upper
Blue Nile Basin, Ethiopia. Research Journal of Agriculture and
Environmental Management, 4(2): 055-068.
Magadza, C.H.D. (1984). An analysis of siltation rates in
Zimbabwe. Zimbabwe Science News, 18(6): 63-64.
Magadza, C.H.D. (1994). Climate change: some likely multiple
impacts in Southern Africa. Food Policy, 19(2): 165-191.
Mantyka-Pringle, C.S., Martin, T.G., Moffatt, D.B., Linke, S. and
Rhodes, J.R. (2014). Understanding and predicting the
combined effects of climate change and land use change on
freshwater macroinvertebrates and fish. Journal of Applied
Ecology, 51(3): 572-581.
Nature & Faune Volume 30, Issue No. 1
41
Midgley, G.F. and Bond, W.J. (2015). Future of African
terrestrial biodiversity and ecosystems under anthropogenic
climate change. Nature Climate Change, 5(9): 823-829.
O'Connor, T.G. and Campbell, B.M. (1986). Hippopotamus
habitat relationships on the Lundi River, Gonarezhou National
Park, Zimbabwe. African Journal of Ecology, 24(1): 7-26.
Schuyt, K.D. (2005). Economic consequences of wetland
degradation for local populations in Africa. Ecological
Economics, 53(2): 177-190.
Tafangenyasha, C. (1997). Should Benji Dam be dredged? A
preliminary impact assessment to dredging a water reservoir
in an African national park. Environmentalist, 17(3): 191-195.
Zisadza-Gandiwa, P., Gandiwa, E., Jakarasi, J., van der
Westhuizen, H. and Muvengwi, J. (2013). Abundance,
distribution and population trends of Nile crocodile
(Crocodylus niloticus) in Gonarezhou National Park,
Zimbabwe. Water SA, 39(1): 165-169.
Zisadza, P., Gandiwa, E., Van Der Westhuizen, H., Van Der
Westhuizen, E. and Bodzo, V. (2010). Abundance, distribution
and population trends of hippopotamus in Gonarezhou
National Park, Zimbabwe. South African Journal of Wildlife
Research, 40(2): 149-157.
ZPWMA (2011). (Zimbabwe Parks and Wildlife Management
Authority) Gonarezhou National Park Management Plan:
2011–2021. Zimbabwe Parks and Wildlife Management
Authority, Harare.
Nature & Faune Volume 30, Issue No. 1
42
Comparative study of the production of maize
cultivars tolerant of low-nitrogen soils, with
and without fertiliser in the Democratic
Republic of the Congo
Jean Pierre Kabongo Tshiabukole*1, Pongi Khonde,
Kankolongo Mbuya, Jadika Tshimbombo, Kasongo
Kaboko, Badibanga Mulumba, Kasongo Tshibanda
and Muliele Muku
Summary
To determine the profitability of the production of maize
varieties tolerant of low-nitrogen soils (low-N), a study was
conducted at the Mvuazi Research Centre. Seven low-N
varieties were compared with two local varieties with and
without fertilizer. Statistical analyses proved a significant
different among the varieties (P<0.05) in both conditions (with
and without fertilizer). The average yield with fertilizer was
higher than the yield without fertilizer. LNTP-W C4 and LNTP-Y
C7 varieties recorded the highest yields of 7,142.8 kg/ha and
7,120.5 kg/ha respectively with fertilizer as compare to 5,960.9
kg/ha and 3,625.6 kg/ha without fertilizer. The production cost
of one kilo of grains without fertilizer was 213.52 Congolese
Francs (FC) as compared to 216.79 FC with fertilizer. The gross
profit margin without fertilizer was 286.48 FC as compared to
283.21 FC with fertilizer. These results show that the use of lowN varieties can improve the productivity of nutrient-poor soils
of farmer fields while minimising production cost.
Introduction
Materials and methods
The study was conducted at the INERA research centre of
Mvuazi in the Democratic Republic of Congo (470 m of
altitude, 14°54'E, and 5° 21'S). The seeds were planted with 75
cm × 50 cm spacing. Two seeds were planted per hole in two
rows of 5 m long in two different conditions: without fertilizer
and with fertilizer. The fertilizers were NPK 17-17-17 (250
kg/ha during sowing) and 60 kg/ha of urea (46% N) on the 15th
and 30th days after sowing. Seven low-N cultivars from the
International Institute of Tropical Agriculture (IITA), namely BR
99 TZL Comp 4 DMSRSR (V1), BR 9928-DMRSR LN C1(V2), LA
POSTA SEQUIA C6 (V5), LNTP-W C4(V6), LNTP-Y C7(V7), TLZ
COMP 1 C6 LN C1(V8), TZPB Prol C4(V9) and two local
cultivars (V3 and V4) were compared. A randomized complete
block design was used. Only grain yields and profit margins
were determined. The general linear model variance was
analysed and significant differences were noted up to 5%.
Results
Yields were higher with fertilizer than without fertiliser for all
cultivars (Table 1). The variance analysis showed a significant
difference (P<0.05) among cultivars in both cases. Where
fertilizer was applied the highest yields were recorded for V6
and V7, although these were not statistically significantly
higher than with V1, V4 and V9.. Very important was the very
good yield of V6 without fertilizer. It actually gave a higher yield
without fertilizer than six of the other cultivars gave with
fertilizer. V5 and V7 also gave fair yields without fertilizer.
These results show the importance of selecting appropriate
cultivars, where fertilizer is available and even more so where
fertilizer is not available.
-1
In Africa, maize yields in farmer fields range from 1 to 2 t ha , in
-1
contrast to the yields of 5-7 t ha reported in research stations
in developed countries [7], and in commercial farms in those
countries. The low yields are due to nutrient-poor soils [3] and
the high cost of inputs [2].
Several studies have proven that 30-50 kg/ha of NPK fertilizer,
combined with 5 t/ha of organic fertilizer (manure) produce
grain yields closer to those of 100-120 kg/ha with mineral
nitrogen alone [6]. The only constraint associated with the use
of this technology is the availability of adequate quantities of
manure. Many studies have shown that there are some maize
genotypes that can effectively use the nitrogen from the soil
[10]. These genotypes can improve the productivity of
nitrogen-poor soils and minimise the use of inorganic fertilizer,
and thereby increase gross profit margins. The aim of this
study was to compare the productivity of low-N tolerant
cultivars in terms of their grain yields and the corresponding
cost of production with a view to minimising the use of
fertilizers in farmer fields.
*1
Jean Pierre Kabongo Tshiabukole (Corresponding author),
National Maize Program INERA Mvuazi/Bas-Congo.
National Institute for Agricultural Research (INERA),
B.P 2037, Kinshasa/Gombe, Democratic Republic of the Congo.
Email: [email protected]
Tel.: 243 (0)815992827
Nature & Faune Volume 30, Issue No. 1
43
Table1. Grain maize yields with and without fertilizer
Yield (kg/ha)
Varieties
WITH
WITHOUT
V1
V2
V3
V4
V5
V6
V7
V8
V9
6,393.4±703.8 bc
3,813.4±254.3 a
3,551.2±420.8 a
5,675.9±85.3 bc
4,886.3±1,796.3 ab
7,142.8±198.6 c
7,120.5±226.3 c
4,972.01±449.9 ab
5,000.4±388.5 ac
2,239.1±544.4 a
1,439.5±644.2 a
2,001.4±661.2 a
2,244.4±642.3 a
3,105.01±503.9 ab
5,960.9±1,643.2 b
3,625.6±584.4 ab
1,472.2±384.2 a
2,038.9±104.9 a
The profit margins per hectare obtained with the nine maize cultivars are very illuminating (Table 2). The production costs were
213.52 FC without fertilizer and 216.79 FC with fertilizer. The maize was sold at 500 FC per kg (1US$ = 950 FC). The highest profit
margin per hectare was obtained with V6 without fertilizer, with V6 and V7 with fertilizer close to it and V1 not far behind.
Table2. Profit margins (gross margins) for nine maize cultivars with and without fertilizer
WITH
Cultivars
V1
V2
V3
V4
V5
V6
V7
V8
V9
WITHOUT
Sale
(thousand
FC/ha)
Profit
(thousand
FC/ha)
Sale
(thousand
FC/ha)
Profit
(thousand
FC/ha)
3196.7
1906.7
1775.6
2838.0
2443.2
3571.4
3560.3
2486.1
2500.2
2084.7
794.7
663.6
1725.9
1331.2
2459.4
2448.3
1374.1
1388.2
1119.5
719.8
1000.7
1122.2
1552.6
2980.5
1812.8
736.1
1019.4
637.1
237.3
518.2
639.7
1070.1
2498.0
1330.3
253.6
537.0
Discussion and conclusion
Several studies on plant selection for the purposes of improving yield on low-nitrogen soils have been conducted on tropical
maize [4]. The results of our study are an indication that the use of fertilizer in required proportions increases grain yields
appreciably for all cultivars used. Both without and with fertilizers there were very big differences between different cultivars.
Without fertilizer, the highest yield was recorded by V6 cultivar, being even higher than the majority of other cultivars gave with
fertilizers. V6 and V7 were chosen specifically on account of their reported ability to tolerate low-nitrogen soils [9]. Plants are
according to their photosynthesis pathway classified as C3 or C4 plants. C4 plants are very efficient plants; among other in the
utilization of N. Maize is a C4 plant, but not a perfect example. Some cultivars are closer to being good C4 examples than others
and in the present study cultivars totalling a number of cycles corresponding to C4, that is, being better C4 examples such as V6,
V7 recorded the highest yields where fertilizer was not applied, with V5, V6 and V7 also giving the highest yields where fertilizer
was applied. These results are in agreement with those of Ajala & al. (2007) [1] and Menkir & al (2006) [8]. According to Bertin &
gallais (2000) [5], the difference in production between the maize lines in their study was due to differences in their ability to
effectively absorb nitrogen.
Nature & Faune Volume 30, Issue No. 1
44
References
1. Ajala, S.O. Menkir, A., Kamara, A.Y. Alabi, S.O., Abdulai, M.S.
2007. Breeding strategies to improve maize for adaptation to
low soil nitrogen in West and Central Africa. African Crop
Science Conference Proceedings Vol. 8. pp. 87-94
2. Azeez, J.O. and Adetunji, M.T. (2007). Nitrogen-use
efficiency of maize genotypes under weed pressure in a
tropical alfisol in Northern Nigeria. Tropicultura 25 (3): 174179.
3. Badu-Apraku, B., Menkir, A., Ajala, S., Akinwale, R., Oyekunle,
M. and Obeng-Antwi, K. (2010). Performance of tropical earlymaturing maize cultivars in multiple stress environments.
Canadian Journal of Plant Science Vol. 90:831-852.
6. Carsky, R.J & Iwuafor, E.N.O. 1999. Contribution of soil
fertility research and maintenance to improve maize
production and productivity in sub-Saharan Africa. Pp 3-20.
7. Fakorede, M.A.B., Badu-Apraku, B., Kamara, A.Y., Menkir, A.
and Ajala, S.O. (2003). Maize revolution in West and Central
Africa: An overview. Proceedings of a Regional Maize
Workshop, IITA-Cotonou, Republic of Benin, 14-18
8. Menkir, A., Ajala, S.O., Kamara, A.Y. & Meseka, S.K. 2006.
Progress in breeding tropical maize for adaptation to suboptimal soil nitrogen at IITA. Paper presented at 42nd Illinois
Corn Breeder's School, Champaign, Illinois, March 6 to 7,
2006.
4. Baenziger M, Edmeades G O, Lafitte HR. 1999. Selection for
drought tolerance increases maize yield across a range of
nitrogen levels. Crop Sci 39: 1035-1040
9. Ogunniyan, D. J., Olakojo, S. A. 2014. Genetic Variability of
Agronomic Traits of Low Nitrogen Tolerant Open-Pollinated
Maize Accessions as Parents for Top Cross Hybrids. Journal of
Agriculture and Sustainability ISSN 2201-4357 Volume 6,
Number 2, 2014, 179-196
5. Bertin, P & Gallais, A. 2000. Physiological and genetic basis
of nitrogen use efficiency in maize I. Agrophysiological results.
Maydica 45, 53-66.
10. Oikeh, S.O. 1996. Dynamics of soil nitrogen in cereal based
cropping systems in the Nigerian savanna. Ph.D. dissertation.
Ahmadu Bello University, Zaria, Nigeria. 1194pp.
Nature & Faune Volume 30, Issue No. 1
45
Effect of no-tillage with mulching on yield of
east African highlands banana intercropped
with beans at Mulungu, in the eastern
Democratic Republic of Congo.
Tony Muliele Muku1
Summary
The objective of this study was to assess the effect of no-tillage
with mulching on yield of East African highlands banana
(Musa AAA-EA) in banana-beans intercropping systems. Two
treatments were compared: Conventional manual tillage
(CMT) with export of crop residues (= T0), and No-till with
banana residues mulch (= T1). Bunch weight was monitored
from 15 mats per treatment replicate throughout 4 crop cycles.
-1
-1
Banana yield (t ha cycle ) was calculated on basis of the
-1
average bunch weight and plant density (2,500 plants ha ).
Treatment and crop cycle had significant effects on banana
yield. For all crop cycles, T1 treatment had higher yields, with
-1
-1
on average 42 t ha vs 36 t ha obtained in the T0 treatment.
Banana yield under T1 increased by 6.7, 8.1, 21.3, and 22.9% in
the first, second, third and fourth cycles, respectively. It is be
concluded that CMT with export of crop residues had negative
impact on the yield of East African highlands banana, and
should be avoided by farmers interested to banana yield.
1. Introduction
Banana-beans intercropping systems are commonly
practised in South Kivu (DR Congo) in order to increase crop
productivity and maximize land use. At the onset of bean
cropping seasons (September and February), the soil
between banana rows is tilled manually to a depth of 15-20
cm, using a hand hoe or a fork to prepare the seedbed for the
beans (Dowiya et al., 2009; Muliele et al., 2015). Farmers
believe that tillage improves the bean performance, but tillage
may possibly seriously damage the superficial banana root
system and consequently negatively affect banana
productivity and increase nematode pressure (Muliele et al.,
2015).
Many studies (e.g. Blomme, 2000; Lassoudière, 1978) have
documented positive correlation between bunch weight or
banana yield and below ground biomass. It is, therefore,
expected that any decrease in root biomass may lead to
decreased production. It is thus hypothesised that pruning
roots to the depth of tillage twice a year by conventional
manual tillage (CMT), and the lack of permanent soil cover will
have negative effects on banana yield. A study was, therefore,
conducted at Mulungu site, comparing conventional manual
tillage (CMT) with export of crop residues with no-till (NT) with
mulching.
2. Materials and methods
The study was carried out at Mulungu research station
(2.335°S, 28.788°E, 1699 m above sea level), South-Kivu in
Eastern Democratic Republic of Congo. The soils are Nitisols
(WRB, 2014) i.e. high quality fertile soils, developed on
volcanic ashes. The soil properties of the topsoil at the study
site are presented in table 1. The climate is Aw3, a tropical
climate with 3 months of dry season (Peel et al., 2007). Annual
average precipitation varies between 1500-1800 mm, and the
growing season extends to over 325 days per year (Muliele et
al., 2015).
The experiment was started in April 2008 in a land previously
under CMT for sweet potatoes (Ipomoea batatas). A
randomized complete block design with four treatments and
four replications was applied: Conventional manual tillage
(CMT) with export of crop residues (= T0), no-till (NT) with selfmulch (T1), NT with self-mulch + Hyparrhenia diplandra grass
mulch (T2) and NT with self-mulch + Tripsacum laxum grass
mulch (T3). Self-mulching consisted in leaving crop residues
(banana and beans after harvest) in the field. External mulches
-1
(T2 and T3) were applied at the rate of 25 t ha dry matter (DM)
-1
in the first year, and 12.5 t DM ha in thesecondyear. Since the
external mulch (T2 and T3) treatments did not affect banana
yield significantly in the first and second cycles they were
abandoned thereafter. A single application of banana
-1
residues mulch (22 t DM ha ) was applied in T1 plots at
planting only. T0 plots were tilled at the onset of each bean
growing season (September and February) to prepare the
seedbed for beans. Bush beans were sown in all treatments at
a density of 250,000 plants ha-1. No mineral fertilizers, organic
manure or pesticides were applied. We assumed that beans
had no significant effect on banana yield. Sword suckers of
banana cultivar “Ndundu” (AAA-EA beer banana) were
planted at a 2 m x 2 m spacing (2,500 plants ha-1). Cultural
practices consisted of de-suckering, male bud removal and
weeding. Bunch weight was recorded through four
consecutive cycles, and banana yield (t ha−1) was then
calculated for each cycle. Bean yield was assessed during six
growing seasons, but was not affected by treatments. Data
analysis was performed using the Statistical Analysis System
package (SAS 9.2 Enterprise Guide 4.2).
1
Tony Muliele Muku,
Institut National pour l'Étude et la Recherche Agronomiques (INERA),
B.P. 2037, Kinshasa/Gombe, Democratic Republic of Congo
Téléphone : (+243) 85 315 88 22 ;
Email : [email protected]
Research was carried out at Mulungu in South-Kivu in the Eastern
Democratic Republic of Congo, from 2008 to 2013.
Hence, the objective of this study was to assess the effect of
no-tillage with mulching on yield of East African highlands
banana intercropped with beans.
Nature & Faune Volume 30, Issue No. 1
46
3. Results and discussion
Table 2 shows that T0 treatment had the lower yield whatever
crop cycles. Statistical analysis revealed significant difference
(P<0.05) between T0 and T1 in the fourth cycle. The lower
banana yield under T0 treatment may be principally attributed
to tillage-induced mechanical damage on banana rooting
system, and/or the lack of permanent soil cover. Differences in
yield between T0 and T1 could not be primarily related to soil
fertility since soil fertility properties were not affected by
treatments (Muliele et al. 2015).
The lower banana yield in the T0 treatment compared with
the T1 treatment during cycle 4 (Table 2) is in agreement with
the lower root length and biomass, and plant growth
previously reported by Muliele et al. (2015) for the same
experiment. This may confirm the strong correlation between
the banana root system and above-ground biomass reported
by many authors (e.g. Blomme, 2000; Lassoudière, 1978).
Muliele et al. (2015) reported that the renewal of banana
rooting system subsequent to tillage requires several months.
Thus, if CMT occurs in the flowering or fruit formation stage,
which is a critical period for water and nutrient uptake, a lower
water and nutrients uptake due to decreased rooting system
may adversely affect the performance of banana. A gradual
increase in difference in banana yield between T0 and T1
treatments through crop cycles (6.7-22.9%) may indicate an
increase of stress with increased number of tillage events.
-1
The lowest yield was observed in the first cycle (33 t ha , mean
-1
of all treatments) compared with other ones (37-49 t ha ). For
banana (Musa spp.), many studies (e.g. Njuguna et al., 2008)
reported lower banana yield in the first cycle compared to
those of subsequent cycles, due to better plant establishment
at the latter cycles than in the first one. We conclude that CMT
with export of crop residues in banana-bean intercropping
systems had negative impacts on banana yield. To increase
the yield of East African highlands banana farmers should
adopt the NT systems. Further observations are needed and
should be aimed at testing the effects of no-till systems on
banana yield in other banana production areas in the East
African highlands.
Table 1. Physico-chemical properties of the topsoil (0-20 cm) at Mulungu site. Values are means ± standard error.
Soil properties
Values
Ntotal(%)
0.42±0.01
Ctotal (%)
5.15±0.15
Exch. Ca (cmolckg-1)
Exch. Mg (cmolckg-1)
18.98±0.75
Exch. K (cmolckg-1)
P available (mg kg-1)
1.23±0.16
4.47±0.19
86.39±4.24
6.3±0.04
pH (H2O)
Clay
Texture
Source: Muliele et al. (2015). Ntotal: total nitrogen, Ctotal: total organic carbon.
-1
Table 2. Banana yields (t ha ) under different soil tillage systems. Values are means (n=4) ± standard error.
Treatments
Crop cycles
T0
T1
T2
T3
C1
30.1±1.8a
32.1±1.9a
33.7±2.5a
35.0±2.0a
C2
46.8±3.7a
50.6±3.2a
49.1±4.3a
51.0±4.6a
C3
35.5±4.2a
43.1±1.7a
Nd
Nd
C4
33.6±2.5a
41.3±1.8b
Nd
Nd
Overall mean
36
42
41
43
Nd: not done. Means (horizontal comparison) with the same letters are not significantly different (P=0.05).
Nature & Faune Volume 30, Issue No. 1
47
Acknowledgments
Author gratefully thank the DGDC, Belgium who, through
CIALCA (Consortium for Improving Agriculture-based
Livelihoods in Central Africa), has funded a part of this study.
Thanks also go to Mrs Cécile Diaka for funding additional data
monitoring.
References
Muliele M.T., van Asten P.J.A., Bielders C.L. 2015. Short- and
medium-term impact of manual tillage and no-tillage with
mulching on banana roots and yields in banana-bean
intercropping systems in the East African Highlands. Field
Crops Research 171: 1-10.
Njuguna J., Nguthi F., Wepukhulu S., Wambugu F., Gitau D.,
Karuoya M. and Karamura D. 2008. Introduction and
evaluation of improved banana cultivars for agronomic and
yield characteristics in Kenya. African Crop Science Journal
16: 35-40.
Blomme G. 2000. The interdependence of root and shoot
development in banana (Musa spp.) under field conditions
and the influence of different biophysical factors on this
relationship. Katholieke Universiteit Leuven, Leuven, Belgium,
p 183.
Peel M.C., Finlayson B.L., McMahon T.A. 2007. Updated world
map of the Köppen-Geiger climate classification. Hydrology
and Earth System Sciences 11: 1633–1644.
Dowiya N.B., Rweyemamu C.L., Maerere A.P. 2009. Banana
(Musa spp. Colla) cropping systems, production constraints
and cultivar preferences in Eastern Democratic Republic of
Congo. Journal of Animal and Plant Sciences 4: 341-356.
WRB (IUSS Working Group). 2014. World Reference Base for
Soil Resources 2014. International soil classification system
for naming soils and creating legends for soil maps. World Soil
Resources Reports No. 106. FAO, Rome.
Lassoudière A. 1978. Quelques aspects de la croissance et du
développement du bananier 'Poyo' en Côte d'Ivoire. Le
système radical. Fruits 33: 314-338.
Nature & Faune Volume 30, Issue No. 1
48
Agro-economic efficiency of mineral and organic
fertilization of beans on the ultisols of the highlands of
eastern Democratic Republic of the Congo
1
1
Audry Muke Manzekele* , Lunze Lubanga , Telesphore
Mirindi1, Benjamin Wimba1, Katcho Karume2, Solange Kazi2,
3
4
5,
Sospeter Nyamwaro , Moses Tenywa , Josaphat Mugabo
6
7
Robin Buruchara , Oluwole Fatunbi , and Adewale
Adekunle8
Summary
Permanent land occupation by intensive crops (beans, maize,
and cassava) has led to serious crop yield reductions in
eastern Democratic Republic of the Congo. Study during two
successive growing seasons demonstrates agro-economic
efficiency of mineral and organic fertilization on beans
induced by few options available and suitable for local
fertilization conditions. Compared to control, NPK (120kgha-1)
indicate improvement in yields by 57 to 95% and value-cost
ratio (VCR) of 1.5 and 4.46 in the first and second growing
seasons respectively, manure (10T/ha) improved yields by 90
-1
-1
to 95%. Combine manure (5T/ha ) and NPK (60kgha )
increased yields by more than 100% and indicate VCR of 1.3
and 1.64 in the first and second growing seasons respectively.
It is therefore possible to improve beans production in upland
eastern DRC and investments are covered after two growing
seasons, resulting in benefits in terms of crop production and
income.
Introduction
Low soil fertility is among the most important yield-limiting
factors in the bean producing highland regions in eastern
parts of the Democratic Republic of Congo (DRC). The major
soil fertility related problems are found to be low available
phosphorus (P) and nitrogen (N), and soil acidity, which is
associated with aluminum (Al) toxicity (Lunze et al. 2002). In
light of these constraints, farmyard manure (FYM) and
compost application are the most common practices on
smallholder farms (Musungayi et al. 1990). To be effective in
bean (Phaseolus vulgaris L.) production requires that they
must be well decomposed (Gurung and Neupane 1988).
Furthermore, large quantities have to be applied (Lunze 1990;
Ngongo and Lunze 2000), which are not accessible to the
majority of smallholder bean growers (Thung and Rao 1999).
According to Vanlauwe et al. (2010), these technologies
should be based on their relevance to local conditions
inherent to both the biophysical and socio-economic
environment of farmers. In this study, we assess the agroeconomic efficiency of local farmyard manure alone or in
combination with mineral fertilizer.
Methodology
The study was conducted in the highlands Ultisols of eastern
DR Congo where the soils have clayey texture (sandy clay
loam), low soil pH, low base saturation and relatively high
organic C contents (Pypers et al. 2010). To increase bean
production NPK at a rate of 120 kg.ha-¹ or local cattle farmyard
manure (FYM) at a rate of 10 t.ha-¹ were applied as a single
dose just before planting. Only at Mulungu a combination of
60 kg.ha-¹ NPK plus 5 t.ha-¹ FYM was also applied as a single
dose at planting. Experiments were conducted at three sites,
namely at the research station at Mulungu and in farmers'
fields at Mulengeza and Kashusha. Treatments were laid out
in a randomized complete block design (RCBD) with eight
farmers chosen randomly in each on farm site as replications.
Data were collected on grain bean yield and subjected to an
analysis of variance to assess the effect of each treatment,
using GenStat 3th Edition. The effects of the different
treatments were compared by computing the least standard
deviation (LSD). Significance of difference was evaluated at
P=0.05. Agro-economic analyses, consisting of calculating
the value-to-cost ratio (VCR) and also the agronomic
efficiency (AE) of the key nutrient (for beans being
phosphorus, P) were done for the Mulungu site, where all
three fertilizer treatments were applied. This is just a case
study example to show the importance of doing these types of
analyses. The calculations were done as follows:
VCR= (Y2-Y1) µ/x
Equation (1)
Where: Y2= yield (kg) produced in the treated plot, Y1 =
produced yield (kg) in the control, (Y2-Y1) = additional yield
(kg) due to the treatment, µ = price of 1kg of the product
and x = fertilizer cost.
AE = (Y2-Y1)/y
Equation (2)
Where: (Y2-Y1) is as above and y = quantity (kg) of P
applied.
1
Institut National pour l'Etude et la Recherche Agronomique. Mulungu,
DS Bukavu, Democratic Republic of the Congo.
*
Audry MukeManzekele (Corresponding author), Institut National pour
l'Etude et la Recherche Agronomique. Mulungu, DS Bukavu,
Democratic Republic of the Congo.
Email : [email protected]
Tel. : +243 997 720 745
2
Katcho Karume and Solange Kazi. Goma Volcano Observatory,
Department of Geochemistry and Environment. 142 Monts Goma,
Goma, North-Kivu Democratic Republic of the Congo
3
Sospeter Nyamwaro, [email protected],
+256 758 545 408,
International Centre for Tropical Agriculture (CIAT), Uganda,
P.O. Box 6247, Kampala, Uganda
4
Moses Tenywa, [email protected],
Makerere University, College of Agricultural and Environmental
Sciences,
P. O. Box 7062, Kampala, Uganda
5
Josaphat Mugabo , [email protected],
Rwanda Agricultural Board, P. O. Box 5016, Kigali, Rwanda
6
Robin Buruchara, [email protected],
+254 718 000986,
International Centre for Tropical Agriculture (CIAT), Africa Office, P. O.
Box 823-00621, Nairobi, Kenya
7
Fatunbi Oluwole,
[email protected],
Forum for Agricultural research in Africa (FARA)
PMB CT 173, Accra ,Ghana
8
Adewale Adenkule,
E-mail: [email protected]
Office of the President. The state House, Gambia.
Nature & Faune Volume 30, Issue No. 1
49
Results and discussions
1. Treatment effects on bean yield
At Mulungu yields were higher in the second season than in the first season. Yields in the first year increased by 57% and 91%,
compared to the control, when NPK (120 kg/ha) or FYM (10 t/ha) were applied respectively, while the combination of 5 t/ha FYM
and 60 kg/ha NPK increased the yield by 164%, i.e. it gave a yield 2,64 times that of the control (Table 1). The latter combination
also gave a statistically significantly higher yield than high rates of NPK or FYM alone. FYM alone was slightly, but not significantly
better than NPK in both seasons. In the second season all treatments increased yields by more than 100% compared to the
control, the increase with NPK plus FYM combination being 170%.
Table 1: Effect of mineral and organic fertilizer on bean yields at Mulungu site in two consecutive seasons
Bean yield (kg/ha)
Treatment
Season 1
Season 2
Cumulative
Control
432.69a
500a
932.69a
NPK (120 kgha ¹)
678.42ab
1065.10b
1743.52b
FYM (10 tha ¹)
NPK (60 kgha ¹) + FYM (5
tha ¹)
827.99b
1229.17cb
2057.16bc
1143.16c
1351.56c
2494.72c
LSD
CV (%)
244.3
273.3
465.9
15.9
16.7
12.8
Means followed by the same letters in the same column are not significantly different at p=5%
At Kashusha yields were also higher in the second season than in the first season where NPK or FYM was applied (Table 2). At
Kashusha both NPK and FYM more than doubled yields, compared with the unfertilized control, in the first season. In the second
season FYM increased the yield to more than three times that of the control in this low yielding soil, while NPK increased the yield
to almost four times that of the control. In the first season FYM did slightly better than NPK, whereas NPK did slightly better than
FYM in the second season. The cumulative yields with NPK and FYM were almost the same after two seasons.
Table 2: Effect of mineral and organic fertilizer on bean yields at Kashusha in two consecutive seasons
Beanyield (kg/ha)
Treatment
Season 1
Season 2
Cumulative
Control
299.58a
272.44a
572.02a
NPK (120kgha ¹)
637.50b
1025.64b
1663.14b
FYM (10tha ¹)
677.8b
913.46b
1591.26b
LSD
CV (%)
164.7
313.5
527.5
28.4
9.9
33.6
Means followed by the same letters in the same column are not significantly different at p=5%
Nature & Faune Volume 30, Issue No. 1
50
At Mulengeza yields were also higher in the second season than in the first season (Table 3). In the first season NPK gave far
more than double the yield of the control, while FYM gave a three times higher yield. In the second season NPK gave a yield more
than double that of the control, while FYM also increased the yield significantly. In this season the yield with NPK was statistically
higher than that with FYM. NPK gave a somewhat, but not statistically significant, higher cumulative yield the FYM over the two
years.
Table 3: Effect of mineral and organic fertilizer on bean yields at Mulengeza in two consecutive seasons
Bean yield (kg/ha)
Treatment
Season1
Season 2
Control
273.33a
462.07a
735.4a
NPK (120 kgha⁻¹)
696.25b
1089.74c
1785.99b
FYM (10 tha ⁻¹)
814.17b
806.62b
1620.79b
373.2
196
455.8
36.3
11
22.2
LSD
CV (%)
Cumulative
Means followed by the same letters in the same column are not significantly different at p=5%
2. The value-to-cost ratio and the agronomic efficiency analyses for Mulungu site
These analyses were done as a case study example to show how important it is to do these types of analyses. It must be kept in
mind that the outcomes of such analyses are unique for each case, because the costs of different inputs and the sale prices of
produce differ widely between different areas and also between different seasons in the same area. It must be kept in mind that a
value-to-cost ratio (VCR) of 1.0 is the break-even point. In other words, when the VCR is above 1.0 it is profitable to apply fertilizer,
but if it is below 1.0 a loss is suffered due to the fertilizer application. In the present example NPK and NPK plus FYM in the first
season gave VCR values above 1.0 that were of the same order, with the combination being slightly inferior (Table 4). This despite
the fact that the combination gave a 70% higher yield than NPK alone, being statistically significantly superior (Table 1). FYM
alone gave a VCR value of far below 1.0. In other words it was not an economically viable option, despite it giving a 22% higher
yield than NPK alone. In the second season NPK alone gave a very high VCR of 4.46. The VCR for the combination was of the
same order as in the first season, but was vastly inferior to that for NPK alone. This despite the fact that the combination gave a 30%
higher yield, statistically significantly superior to NPK alone. FYM alone again gave a VCR lower than 1.0. From an economic point
the very high input cost of the manure compared with a much lower input cost for the inorganic NPK fertilizer was an important
economic determinant. The manure part of the combined fertilizer clearly also hampered the profitability of the combination,
despite its good yield response. This is quite opposite to the normally perceived situation in Africa. This is due to the small number
of livestock in the study area following the two decades of repetitive wars; characterized by the looting of animals by militiamen
and soldiers of the regular army. Making it therefore difficult to obtain a sufficient amount of manure by farmers in the region.
The differences in VCR were not related to the agronomic efficiency of the P in the fertilizers (Table 4). NPK, the most profitable
fertilizer, had the poorest agronomic efficiency (AE) values. In the first season it was not statistically inferior to FYM but was
percentage wise much lower. The combination fertilizer gave excellent AE values in both seasons. In the first season it was far
superior to the others. In the second season it was not statistically significantly better, but still 49% higher than NPK alone.
Nature & Faune Volume 30, Issue No. 1
51
Table 4: Cost effectiveness and agronomic efficiency of inorganic NPK fertilizer and farmyard manure for beans
VCR
AE
VCR
AE
NPK (120 kg/ha)
1.50
12.05
4.46
28.26
FYM (10 t/ha)
0.45
19.76
0.65
35.74
1.37
47.36
1.64
42.16
NPK (60 kg/ha) + FYM (5 t/ha)
LSD
0.9ns
18.6*
1.56*
16.92ns
CV (%)
36.1
30.2
40.1
27.6
LSD– Least standard of difference and ns – not significant. * LSD significant at P≤0.05.
Treatments as experienced in this study had significant effects on production. Marginal rates of observed yields met the
minimum value of 118% (CIMMYT, 1998). Economics analyses at Mulungu site show that, 1$ USD invested in fertilizer gain 0.5 $
USD and 3.46 $ USD respectively in the first and second season. In fact, benefit on investment in fertilizer can be obtained despite
the high fertilizer price in the area, which is more than twice as high as in Kenya and Uganda (Pypers et al., 2010). The economic
analyses show that when the VCR is above 1.0 it is profitable to apply fertilizer, but if it is below 1.0 due to the poor quality of the
technology (Sebahutu, 1988); a loss is suffered due to the fertilizer application. Makinde et al. (2007) demonstrated this in
cassava–legume intercropping systems, increasing net benefits by on average 700$ USD ha-¹ (value-to-cost ratio of fertilizer
use=6.7). However, in this study case, benefit from use of local FYM requires very large quantities that are very expensive to the
majority of bean growers who are smallholder farmers as indicated above given the insecurity state of the area following the two
past decades of repetitive wars in eastern D.R. Congo. Adjei-Nsiah et al. (2007) advised that technologies should suit the needs
and resources available to the target farmer groups.
Conclusion
The study demonstrates the possibility to increase bean production in the Ultisol of eastern Democratic Republic of Congo
highlands and how important it is to do economics analyses. The study demonstrates also, that the outcomes of economics are
unique for each case, because the costs of different inputs and the sale prices of produce differ widely between different areas
and also between different seasons in the same area. The use of local FYM do not increase bean yields nor improve benefits
probably due to both the poor quality and high price of the amendment. Considering the socio-economic conditions of beanproducers in the study area, combining mineral fertilizer and local FYM at small rate may have benefits, but cannot simply replace
the mineral fertilization (NPK), because it has high returns. Methodologies are therefore needed to stimulate acceptance by local
farmers, and may include reduced delay of applying fertilizer. Although inorganic fertilizer has highest benefit, a better
understanding of the conditions under which local FYM (available) is obtained can enable better targeting and adaptation of the
relative technologies.
References
Adjei-Nsiah, S., Kuyper, T.W., Leeuwis, C., Abekoe, M.K., Giller, K.E., 2007. Evaluating sustainable and profitable cropping
sequences with cassava and four legume crops: effects on soil fertility and maize yields in the forest/savannah transitional agroecological zone of Ghana. Field Crop. Res. 103, 87–97.
CIMMYT,1988. From Agronomic Data to Farmer Recommendations: An Economic Training Manual. Completely revised
edition. CIMMYT, Mexico D.F., 1998, pp. 63–71.
Gurung, G.B. and Neupane, R.K.1988. An estimate use of farm yard manure/compost in field crops in Koshi Hills. PAC Working
Paper, No 23.
Lunze L., 1990. Possibilité de gestion des sols au Sud-Kivu montagneux: Rapport annuel de l'Institut National pour l'Etude et la
Recherche Agronomique/Mulungu. Décembre 1990.
Lunze, L., 2000. Possibilités de Gestion de la fertilité de sol Au Sud-Kivu Montagneux. Cahiers du CERPRU No. 14, pp. 23–26.
Lunze, L., Kimani, P.M., Ndakidemi, P., Rabary, B., Rachier, G.O., Ugen, M.M. & Nabahungu, L., 2002. Selection of bean lines
tolerant to low soil fertility conditions in Africa. Bean Improvement Cooperative, BIC Volume 45, pp. 182–183
Nature & Faune Volume 30, Issue No. 1
52
Makinde, E.A., Saka, J.O., Makinde, J.O., 2007. Economic
evaluation of soil fertility management options on cassavabased cropping systems in the rain forest ecological zone of
South Western Nigeria. Afr. J. Agric. Res. 2, 7–13.
Kasereka, Masamba Walangululu, Bernard Vanlauwe.
2010. Increased productivity through integrated soil fertility
management in cassava–legume intercropping systems in
the highlands of Sud-Kivu, DR Congo
Musungayi, T., L. Sperling, W. Graf et L. Lunze. 1990.
Enquêtes diagnostiques de la zone de Walungu. Zone
d'action de la femme solidaire pour le développement du
Bushi. PNL-INERA-Mulungu, DS Bukavu, République
Démocratique du Congo.
Sebahutu, A. 1988. Résultats de la recherche sur la
fertilisation du haricot au Rwanda. In : Actes du
4èmeSéminaire Régional sur l'amélioration du haricot dans la
Région des Grands Lacs, 21-25 November 1988. Bukavu
(Zaïre). CIAT African Workshop Series, No.9. pp. 81-89.
Ngongo, M. et L. Lunze. 2000. Espèces d'herbe dominante
comme indice de la productivité du sol et de la réponse du
haricot commun à l'application du compost. African Crop
Science Journal 8(3): 251–261.
Vanlauwe, B., Bationo, A., Chianu, J., Giller, K.E., Merckx, R.,
Mokwunye, U., Ohiokpe- hai, O., Pypers, P., Tabo, R.,
Shepherd, K., Smaling, E., Woomer, P.L., Sanginga, N.,
2010. Integrated soil fertility management – operational
definition and consequences for implementation and
dissemination. Outlook Agric. 39, 17–24
Pieter Pypers, Jean-Marie Sanginga, Bishikwabo
Nature & Faune Volume 30, Issue No. 1
53
Physico-chemical Properties of Soils Under
Oil Palm Plantations of Different Ages
Sebastian Wisdom Brahene1, Emmanuel OwusuBennoah2, and Mark K. Abekoe3
Summary
The removal of forest cover for oil palm cultivation has raised
concerns especially in the wake of issues and discussions
revolving around climate change and its associated effects.
The nature of pruned materials from the trees do not make
them suitable for use as mulch cover on the whole farm but are
heaped at some areas on farms. The objective of this study
examined the changes in some soil physical and chemical
properties under oil palm plantations with time in the Eastern
Region of Ghana. Oil palm plantations of different ages (0-5, 510, 10-15, 15-20 and 20-25 years) were chosen based on
similar land history. Sites selected were fairly located at the
bottom slope on Oda soil Series (Aeric Endoaquent). On the
same farm two different samples were taken; first under alleys;
and secondly under heaped pruned branches. A reference
site (uncultivated) also located on Oda soil Series was selected
from a forest reserve and used as a standard (control). Particle
size analyses showed that all soils were of sandy loam texture.
All soils were acidic with pH below 5.5, relatively low CEC and
with low per cent base saturation. Bulk density values varied
with age and depth. Soils under prunnings had relatively lower
bulk densities than those under alleys. Nitrogen content was
largely dependent on C content since it was derived from the
mineralisation of OM which served as the main source of N
supply in the absence of external input.
Introduction
To meet the growing demands for food and other services,
agriculture has had to undergo some form of transformation
(Serpantié, 2003). In the Eastern Region of Ghana
interventions have led to growing of various cash crops such
as cacao, rubber, coffee, etc. instead of food crops due to the
strongly acid, extremely infertile, highly weathered and highly
leached soils present in this area. Among the high value
perennial tree crops oil palm has been adopted and grown by
smallholder farmers and other private agencies and
government. Oil palm production has been documented as a
cause of substantial and often irreversible damage to the
natural environment. Clay (2004) reported that the negative
impacts of oil palm on the environment include deforestation
and habitat loss of critically endangered species and a
significant increase in greenhouse gas emissions (Bates et al.,
2008). There have also been arguments that oil palm is a
nutrient miner and adds nothing to the soil. However, during
cultivation of oil palm local farmers engage in pruning and the
heaping of palm fronds (leaves) in between the rows of plants.
Most of these farmers do not add any external input to their
farms. The heaping of palm fronds has been observed to be a
source of organic material addition to the soil. This material
has been found to play a vital role in the maintenance of soil
organic matter (SOM) and nutrient cycling in most
smallholder and large scale oil palm farming systems in the
tropics (McNeil et al., 1997; Cadisch et al., 2002b). This
management practice by farmers serves as a potential means
of contributing C to the soil under oil palm. From an agroecological perspective, OM and its main constituent carbon
play a crucial role in the functioning of these ecosystems.
They actually affect physical, chemical and biological
properties of soils which influence growth (Batjes, 2001; Feller
et al., 2001). There is a need therefore to assess the soil quality
under smallholder oil palm plantations with particular
reference to pruning and heaping of palm fronds on farms to
assess the beneficial effect of this management practice on
soil properties. The objectives of this research were to assess
soil physical and chemical properties under pruned heaps in
already established oil palm plantations of different maturity
ages and to examine the dynamics (changes) over time under
frond heaps in these plantations.
.
Materials and methods
Private oil palm plantations owned by local farmers within the
Kwaebibirim District of the Eastern Region of Ghana were
selected with a reference soil, (uncultivated forest soil) taken
from the Forest and Horticultural Crops Research Centre,
Okumaning within the same district. These oil palm farms
were at different maturity ages from very young ones of about
three months old to farms as old as twenty-five years.
Sampling of farms begun with creating five clusters according
to age of oil palm plantation into which various farms were
grouped. A total of fifteen farms were selected for sampling
with three farms representing each age group as replicates.
Soils were sampled from a depth of 0-10 and 10-20 cm. The
various age groups considered were 0-5, 5-10, 10-15, 15-20
and 20-25 years. Sampling was preceded by marking out an
area 25 m by 25 m. These sampling plots contained both
alleys between rows of palm trees and pruned and heaped
palm fronds within the palm rows. Core samplers were driven
into the ground to take undisturbed soil samples within the
alleys and under heaped branches for bulk density analysis.
Sampling under the prunings was done carefully, especially
under old heaps, since there was the need to distinguish the
top layer from the decomposed material sitting just above it.
Soils from the sampled spots from each farm were put
together to obtain a composite sample. A sub-sample was
taken, air dried, crushed and sieved through a 2 mm sieve and
processed for laboratory analyses.
1
Sebastian Wisdom Brahene , Regional Office for Africa, United Nations
Food and Agriculture Organization, P. O. Box GP 1628 Accra. Ghana.
Tel.: (233) 302 675000 Extension 42209. Cellular. (233) 277 146372;
Fax: 233 302 668 427 ,
Email : [email protected] Email : [email protected]
2
Emmanuel Owusu-Bennoah, Senior Lecturer Department of Soil
Science University of Ghana, Legon
Tel.: +233-24 4772257
Email: [email protected]
3
Mark K. Abekoe, Senior Lecturer Department of Soil Science,
University of Ghana, Legon
Tel.: +233-27 7683576
Email: [email protected]
Nature & Faune Volume 30, Issue No. 1
54
Bulk density, particle size analysis (Bouyoucos Hydrometer,
Day (1965)), pH (CaCl2) (Electrometric), Organic Carbon (Wet
Oxidation, Walkley and Black (1934)), Total Nitrogen (Kjeldahl
Digestion, Bremner (1960)), Exchangeable bases and CEC
(1M Ammonium acetate solution at pH 7.0) were among the
properties determined. Genstats (12th Edition) and Minitab
(16th Edition) were used for computer analyses. Separation of
means was done using the Least Significant Difference (LSD)
method particularly Tukey family test method of means
separation in Minitab. All tests were conducted at a
significance level of 5%.
up the forest caused a further increase in acidity (drop in pH).
Similar results have been published by Nye and Greenland
(1965) for this district. The low pH of the soils may be due to the
nature of the parent materials and to the high rainfall (usually
2000mm and above) (Tweneboah, 2000) which causes
intense leaching of basic cations in the forest soil. The low pH
values imply the presence of a positively charged colloidal
surface capable of attracting negatively charged ions. The
different amounts of organic material present at each location
contributed to slightly higher pH under prunings than within
the alleys.
Results and discussion
Exchangeable K in the uncultivated soil at 0-10 cm depth was
higher than the various groups of oil palm soils both in alleys
and under palm fronds. At 10-20cm depth exchangeable K is
extremely low in both forest soils and oil palm soils. The
exchangeable Na trend appears to be higher in the oil palm
soils both in alleys and under heaped fronds. It is lower at both
depths for all time groups than in the uncultivated soil. The
level of the exchangeable Na appears to be too low to cause
any concern about any possible soil physical impact. As
shown in Tables 1 and 2, there is a definite trend for
exchangeable Ca to be much lower in all time groups of oil
palm soils in both the alleys and under heaped fronds than in
the forest soil at both depths, especially at 0-10 cm, and is a
little lower in the alleys than under heaped fronds. The data
show that there is a definite trend for Mg to be much higher in
the uncultivated soil than with cultivation at both depths. In
general, the exchangeable Mg values initially tended to
increase with time in both alleys and under heaped fronds but
declined steadily with further age of plantation.
The physico-chemical properties of soils are presented in
Tables 1 and 2.
Pruning and heaping of palm fronds on farms starts from 5
years onwards and so marks the beginning of dynamics
distinct from 0-5 years. The 0-5 years samples enable
comparison between the reference and cultivated site just
after clearing.
Particle size analyses showed that the texture of all the soils
was sandy loam. The minor differences observed in texture
could be attributed to spatial differences between soils with
less variation associated to cultivation. A general increase in
bulk density with depth was observed under both prunings
and alleys. This may be attributed to the increasing clay
content with depth. Bulk density values under prunings were
relatively lower than those of the alleys as a result of the
influence of organic matter which made the soils in the 0-10
cm layer relatively loose as compared to those in the 10-20 cm
layer where OM content was quite low. Organic matter played
a key role in improving the physical properties of the soil,
thereby contributing to the structural stability (Schnitzer and
Khan, 1975) as has been seen in the BD values under prunings
(Table 1).
The average pH values did not differ significantly between the
0-10 and 10-20 cm layers. The pH of soil within the oil palm
alleys became lower than those under pruned fronds as the
number of years increased. The forest soil was acidic. Opening
The low values recorded for the basic cations could be due to
the low organic matter content and kaolinitic dominated clay
fraction (Owusu-Bennoah et al., 2000). This also reflected in
the low per cent base saturation of less than 30%. Per cent
base saturation (PBS) of the uncultivated soil decreased
slightly with depth while a general increase was seen under
alleys with depth. The trend with age of plantation is
somewhat inconsistent. The low PBS could also be explained
by the high rainfall which leaches more basic cations out of the
top layer and low organic matter thereby affecting CEC values.
Nature & Faune Volume 30, Issue No. 1
55
Nature & Faune Volume 30, Issue No. 1
56
BD pH
K+
Na+
Ca2+
Mg2+ CEC
BS
TN
OC
BD
pH
K+
Na+
Ca2+
Mg2+ CEC
Mg/m3 CaCl2 (1:2) --------------------------cmolc/kg-----------------------%
g/kg
g/kg
Mg/m3
CaCl2 (1:2) --------------------------cmolc/kg-------------------------- %
g/kg
--------------------------------------------------------0-10 cm ----------------------------------------------------- ------------------------------------------------------- 10-20 cm ----------------------------------------------------------------1.36a 4.8a 0.18c
0.35a
3.0d
1.8c
18.5a
28.8a 1.44a
25.5d
1.46b
4.6a
0.05b
0.22b
2.4d
1.6c
16.5a
1.24c 4.0a 0.13a
0.24b
2.1ae
1.3c
15.6a
24.0a 1.87c
22.3c
1.48b
4.1a
0.08b
0.32ab
1.3c
0.7b
11.1a
1.34a 3.6a 0.11a
0.31a
1.4c
0.9ab
15.9a
17.1a 1.19a
14.6ae 1.43b
3.4a
0.07b
0.24b
1.3c
0.9b
12.2a
1.18c 4.7a 0.10a
0.39a
2.4a
1.5ac
17.5a
25.2a 1.23a
15.6a
1.40abe
4.9a
0.06b
0.36ab
1.8b
0.9b
14.5a
1.21c 4.0a 0.08a
0.29a
2.1a
1.4ac
18.8a
21.0a 1.32a
16.6a
1.36abe
4.0a
0.05b
0.27ab
1.7b
0.7b
14.0a
1.15d 4.5a 0.10a
0.32a
2.6a
1.3ac
17.3a
24.6a 1.87c
22.3c
1.34ae
4.4a
0.06b
0.29ab
1.9b
0.9b
13.3a
BD pH
K+
Na+
Ca2+
Mg2+
CEC
BS
Mg/m3 CaCl2 (1:2) ------------------------cmolc/kg--------------------------%
------------------------------------------------------0-10 cm ------------------------------------------------------1.36a 4.8a 0.18c
0.35a
3.0b
1.8c
18.5a
28.8a
1.24c 4.0a 0.13a
0.24b
2.1b
1.3a
15.6a
24.0a
1.36a 3.6a 0.08a
0.23b1.3a 0.7a
17.5a
13.3a 1.36a
1.33a 4.5a 0.11a
0.35a2.1ab 1.1a
15.8a
22.8a 1.52a
1.28d 3.9a 0.10a
0.32a1.8a 0.9a
18.9a
16.6a 1.60a
1.35a 3.7a 0.13a
0.38a1.7a 0.9a
16.8a
18.9a 1.37a
TN
OC
BD
pH
K+
Na
Ca2+
Mg2+
CEC
g/kg
g/kg
Mg/m3
CaCl2 (1:2) -------------------------- cmolc/kg --------------------------- %
-----------------------------------------------------------10-20 cm -------------------------------------------------------------1.44a
25.5e
1.46b
4.6a
0.05b
0.22b
2.4b
1.6ac
16.5a
1.87b
22.3f
1.48b
4.1a
0.08b
0.32ab
1.3a
0.7a
11.1a
13.7a
1.49b
3.5a
0.05b
0.27b
1.3a
0.6a
13.6a
14.3a
1.44b
4.6a
0.06b
0.36ab
1.6a
1.1a
10.7a
16.9c
1.57e
3.5a
0.06b
0.32ab
1.4a
1.1a
14.9a
13.0a
1.52b
3.6a
0.06b
0.30ab
1.4a
0.7a
10.9a
*1= Uncultivated; 2= 0-5 years; 3= 5-10 years; 4= 10-15 years; 5= 15-20 years and 6= 20-25 years. *BD= Bulk density, Soil texture= Sandy loam; Means without the same letter are significantly different
1*
2*
3*
4*
5*
6*
No.
Table 2 Physico-chemical properties of soils within the oil palm alleys and the reference (uncultivated) soil
*1= Uncultivated; 2= 0-5 years; 3= 5-10 years; 4= 10-15 years; 5= 15-20 years and 6= 20-25 years. *BD= Bulk density, Soil texture= Sandy loam; Means without the same letter are significantly different
1*
2*
3*
4*
5*
6*
No.
Table 1 Physico-chemical properties of soils under oil palm heaps and the reference (uncultivated) soil
25.5a
21.3a
16.9b
28.8b
19.7b
21.8b
BS
g/kg
25.5a
21.3a
20.2a
21.6a
21.2a
23.1a
BS
g/kg
0.53a
0.73b
0.70b
0.72b
0.88b
0.84b
TN
g/kg
0.53b
0.73b
0.70b
0.72b
0.96bd
1.27d
TN
15.2c
11.02g
6.49b
6.83b
9.52d
8.68d
OC
15.2a
11.0d
8.42b
8.68b
10.8d
13.1e
OC
There was a significant drop of OC with cultivation. However,
beyond 10 years it was observed that there was a build-up of
OC especially in the 0-10 cm depth in both alleys and under
heaped fronds except that values observed under heaped
fronds were slightly higher. Beyond 20 years the OC increased
sharply in soils under heaps whiles it declined in soils within
the alleys. The removal of existing forest vegetation cover for
oil palm produces enough biomass which not burnt is broken
down by litter-feeding invertebrates such as termites,
earthworms and beetles. Their actions while decreasing litter
to tiny particles increases the surface for bacterial and fungal
decomposition (MacKinnon et al., 1996) and account for the
difference in OC values between the uncultivated and 0-5
years group. The high OC content of soils under prunings as
compared to those under alleys is due to the amount, location,
quality and action of temperature and moisture on the pruned
material (Kirschbaum, 2000; Raich and Tufekcioglu, 2000).
The trend in OC observed under prunnings was an opposite
of what was seen under alleys where palm fronds heaped
underwent rapid decomposition especially in the 5-10 years
period to release nutrient. However, as the age of the
plantation moved towards the 20-25 years period, the rate of
decomposition slowed down with decomposed material
being protected by overlying palm fronds. It was therefore
common to find heaps of varying heights with age of the
plantation. Similar observations had been made in Benin
(Henson 1999).
Total N varied with amount of OM present in soils such that it
increased along with changes in corresponding OM levels.
However, some exceptions were associated with the
uncultivated, 0-5 and the 20-25 year groups under prunnings
for both depths where corresponding N contents did not
appear to correspond with the high OC values observed. It is
possible that part of the N present in these soils (under
prunnings) were immobilised with increasing age of
plantation with some being protected in the interior of soil
particles (Davidson and Janssens, 2006). The C:N ratio
calculated increased when increases in C were not
accompanied by N additions and this change in C:N ratio had
a large potential effect on processes of mineralization,
immobilization (Paterson, 2003). Farmers under production
systems are expected to keep C:N ratios below 12 to promote
activities of soil microorganisms to release nutrients. The
relatively lower C:N ratios observed for some age groups
compared to the rest under alleys promoted N mineralisation
and more rapid soil N turnover (Cheng et al., 1996) with the
higher C:N ratios possibly slowing down microbial activity and
decomposition as N becomes limiting particularly under
prunings during initial periods (years) of decomposition of
palm fronds. Increase in C under prunings not corresponding
to increase in N especially for the 20-25 years group was partly
due to different rates of decomposition of the two nutrients
such that C appeared to be decomposing faster than N.
Conclusion and recommendation
The study concludes that nutrient mining in oil palm fields is
possible as reduction in Ca, Mg and K were observed with
continuous cultivation without replenishment. Heaping of
palm fronds yielded some benefits in terms of C content with
time but could not supply enough Ca, Mg and K to replace
what the crops used. High temperatures hastened the rate of
decomposition where nutrient release was faster than could
be immediately absorbed and used by plants and were at
times subject to losses associated with high precipitation.
Beneficial effect of OM addition to soils was seen as prunings
improved soil structure to the point that bulk density values of
soils under heaps were relatively lower than those within
alleys. The higher bulk densities under alleys could be
attributed to human activities such as walking during
harvesting and partly to the low C content of the soils. The
study recommends research into how to effectively use
pruned branches for compost to be applied in rings around
the oil palm trees.
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(2008). Climate Change and Water. Technical Paper of the
Intergovernmental Panel on Climate Change, IPCC
Secretariat, Geneva, 210 pp.
Batjes N.H. (2001). Options for Increasing Carbon
Sequestration in West African Soils: An Explanatory Study with
Special Focus on Senegal. Land degradation dev 12(2):131142
Bremner J.M., (1960). Determination of N in Soil by Kjeldahl
Method. Journal of Agricultural Science, 55: 11-33.
Cadisch,G., Ndufa, J.K., Yasmin, K., Mutuo, P., Baggs, E.,
Kaerthisinghe, G. & Albrecht, A. (2000b). Use of Stable
Isotopes in Assessing Belowground Contributions to N and
Soil Organic Matter Dynamics. In: International union of Soil
Science, The Soil and Fertiliser Society of Thailand, Ministry of
Agriculture and Cooperatives of Thailand (Eds) 17th World Soil
Science Conference 'Soil Science Confronting New Realities
in the 21st Century'. International Soil Science Society,
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Hoffman, C.A. (1996). Is Available Carbon Limiting Microbial
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Clay, J. (2004). World Agriculture and the Environment. World
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of Soil Carbon Decomposition and Feedbacks to Climate
Change. Nature 440, 165–173.
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Nature & Faune Volume 30, Issue No. 1
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Analysis. In: Black et al. (Eds) Methods of Soil Analysis, Part I,
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Feller C., Albercht A., Blanchart E., Cabidoche Y.M., Chevalier
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Elsevier Science.
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with Special Reference to West Africa Cash Crops. Co-Wood
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Method of Determining Soil Organic Matter and a Proposed
Modification of the Chronic Acid Titration Method. Soil
Science 31: 29-38.
Nature & Faune Volume 30, Issue No. 1
58
Utilization of aerobically composted wood
waste and chicken manure as organic
fertilizer
Stephen Okhumata Dania1, Lucy Eiremonkhale2, and
Margaret Iyabode Dania3
Summary
Poultry manure, wood shavings and sawdust were
composted together under aerobic conditions for sixteen
weeks. The composted samples were analyzed for nutrient
content, fungi isolation and identification. Aerobic compost of
1g was diluted serially from 10-1 to 10-6 and 10-4, 10-5 and 10-6
dilution were cultured on Potato Dextrose Agar (PDA). Fungi
were identified by their morphological characteristics and with
the use of electric photo microscope. The fungi isolated were
Aspergillus flavus, Aspergillus myzae, Aspergillus candidus,
Aspergillus niger, Aspergillus ustus, Penicillium camemberti,
Penicillium corylophilium, Penicillium enchiopicum,
Penicillium aethiopicum, Penicillium oxalicum, Eurotium
herbariorum and Fusarium species. The compost
composition was high in organic matter and nutrient elements
which can be used to enrich the soil for maximum and
sustainable crop production. The paper thus discusses the
wide variety of microbes carrying out decomposition of the
composting material, highlighting the role of a range of fungi.
Several fungi are known to be particularly effective in
decomposing woody material, such a wood shavings. It
emphasizes a way of getting rid of a mixture of problem
materials in an advantageous way.
Introduction
The menace caused by disposal of wood shavings and
sawdust around houses, streets and major roads and by
droppings from poultry houses demand means to reduce
these environmental problems. This led to the idea of
composting these organic wastes since composting is a
means of reducing both the volume of organic waste and
environmental pollution and using the material
advantageously. Compost is a rich source of organic matter,
which plays an important role in sustaining soil fertility. In
addition to being a source of plant nutrients, it improves the
physical, chemical and biological properties of the soil. Due to
these improvements to the soil, crops become less vulnerable
to stresses such as drought, diseases and toxicities. These
advantages manifest themselves in reduced cropping risks,
higher yields and lower need for the use of inorganic fertilizer
by farmers (Jambhekar 2002).
Poultry manure is an organic waste material consisting of
faeces and urine. Poultry manure is an excellent fertilizer
material because of its high nutrient content, especially
nitrogen (N), phosphorus (P) and potassium (K). Manure is
decomposed in the soil and releases nutrients for crop uptake
by means of a process called mineralization (Jacobs et al.
2003). To mineralize these organic material micro-organisms
are required. Decomposition of organic waste is mediated by
bacteria and fungi. Fungi are important for decomposing
lignified materials, such as wood (Gautam et al. 2010). Dubey
and Maheshwan (2005) reported that the cellulytic fungi such
as Aspergillus, Penicillum, and Trichodema and Trichurus
accelerate composting for efficient recycling of waste with
high C/N ratio and reduce the composting period. It is
therefore important to determine the nutrient content of
composted poultry manure, wood shavings and sawdust. It is
of scientific interest to identify and characterize the microbes
responsible for the decomposition of the materials.
Materials and methods
Composting materials and procedures
The composting was carried out at Ambrose Alli University,
Ekpoma, Edo State, Nigeria. The compost was prepared by
using sawdust and wood shavings collected from sawmills,
poultry manure from battery cage systems and top soil. The
materials were mixed in the following ratios: 20 kg of dried
sawdust and wood shavings, 10 kg of poultry manure and 3
kg of top soil. The materials were mixed with water in a basket
to raise the soil water content ( on a mass basis) to 50%, which
is in the suitable range for micro-organisms responsible for
decomposition (Wipo, 2011). Proper turning was done
weekly to ensure good aeration and the process was
continued for sixteen weeks. At the end of composting, a
composite sample was collected for chemical laboratory
analyses.
Chemical analyses
The following chemical analyses were done on the compost
(to determine its value as fertilizer material): The pH was
determined in water (ratio1:1, soil: water) (Bouyoucos, 1962).
Organic carbon was determined by wet dichromate method
(Nelson and Sommer, 1975) and available phosphorus by
Bray 1 extraction method (Anderson and Ingram, 1993). Total
nitrogen was determined by Kjeldahl method (Bremner and
Mulvaney, 1982). Exchangeable cations (potassium, calcium
and magnesium) were extracted by 1M ammonium acetate,
potassium was then determined by flame photometer while
calcium and magnesium were determined by atomic
absorption spectrophotometer (IITA, 1979). Micronutrients
such as copper, zinc, iron and manganese were also
determined (Lindsay and Norvell, 1978).
1
Dania Stephen Okhumata.
Department of Soil Science, Faculty of Agriculture, Ambrose Alli
University, PMB 14, Ekpoma, Edo State, Nigeria.
Email: [email protected]
Tel.: (234) 8034783383
2
Eiremonkhale Lucy,
Department of Soil Science, Faculty of Agriculture, Ambrose Alli
University, PMB 14, Ekpoma, Edo State, Nigeria.
Email: [email protected]
3
Dania Margaret Iyabode,
Auchi polytechnic, Auchi, Department of Food Technology, PMB 13,
Edo State, Nigeria.
Email: [email protected]
Tel.: (234) 8060565347
Nature & Faune Volume 30, Issue No. 1
59
Fungi isolation and identification
Table 1: Nutrient content of aerobic compost
Isolation
Sterilization
The culture media (Potato Dextrose Agar and saline water)
and equipment used for analysis were sterilized for 15 minutes
in an Autoclave at 121OC .
Preparation of culture medium
To prepare the Potato Dextrose Agar (PDA) medium 16.38 g of
it was dispensed into 420 ml distilled water and
O
homogenized. This was autoclaved at 121 C for 15 minutes,
before adding 0.03 g chloramphenical to inhibit bacterial
growth. The plates were plated in triplicate.
Procedure for isolation
An amount of 9 g sodium chloride was dispensed in 200 ml
distilled water and 9 ml of the solution sterilized by Autoclave
O
for 15 minutes at 121 C and allowed to cool. Compost
samples of 1g were dispensed into 10ml sodium chloride
solution in test tubes, giving a 10-1 compost solution
suspension, and serially diluted from 10-1 to 10-6. From the 10-4,
10-5 and 10-6 dilutions 1ml samples were measured into six
petri dishes (that contain culture medium).
Units normally
given as
Parameter
Values
pH
-
7.65
OM
%
48.70
Total N
%
4.50
Available P
%
0.80
Exchangeable Ca
Centimol(cmol)
(+)/kg
Centimol (cmol)-a
standard unit for
expressing the
concentration of
cations in a
comparable way
1.28
Exchangeable Mg
cmol(+)/kg
1.55
Exchangeable K
cmol(+)l/kg
1.87
Exchangeable Na
cmol(+)/kg
0.08
Extractable Mn
mg/kg
291.17
Extractable Fe
mg/kg
2,892.15
Extractable Cu
mg/kg
24.02
Extractable Zn
mg/kg
106.00
Identification
Fungi in the isolates were identified on the basis of
conventional culture and morphological characteristics.
Electric photo microscopy was also used for further
identification, viewing the slides at 100X objective.
Results and discussion
Compost making is a simple means of improving soil fertility
status and sustain crop production as well as reducing
farmers dependence on mineral fertilizer. The chemical
composition of compost was highly dependent on the
composition of the materials used in the initial mixture, but the
actual concentrations differ markedly because of the changes
in the residual amount of material. The analysis of the compost
showed that it was rich in mineral nutrients and organic matter
(Table 1).
The pH of the compost was alkaline and similar results have
been reported by Albaladejo et al.(2009). It therefore means
that compost can be used as a source of liming to reduce soil
acidity. The organic matter content of the compost was high
and according to several authors, the reason for compost
production is to improve the organic matter content of a
degraded soil. Therefore, compost is an organic matter
resource that has the ability to improve the chemical, physical,
and biological characteristics of soils. According to Van
Zwieten (2009) compost has a high nutrient content,
especially nitrogen, phosphrous and potassium (K). It also
contains micronutrients and this is confirmed by the analytical
values of the compost that was prepared. According to
Edward et al.(2007) a good quality compost has a significant
impact in improving soil quality and crop yield.
The temperature was taken during composting and it was
observed that there was an increase in temperature during the
first three weeks from mesophilic to thermophilic phase and
thereafter the temperature began to decrease. Gautam et
al.(2011) reported a similar trend in temperature during
composting. It was also observed that in order to achieve a
successful composting, the influencing factors such as
temperature, moisture content, aeration, pH, C/N ratio and
composting mixtures should be appropriately controlled
(Michel et al., 1996).
Compost prepared from the combination of two or more types
of wastes enhanced fungi growth and diversity of saprophyte
microorganisms that play an important role in biodegradation.
Fungi isolated are discussed below: The Aspergillus sp.
isolated were; Aspergillus ustus, Aspergillus myzae,
Aspergillus niger, Aspergillus candidus, Aspergillus flavus. A
total of six Penicillium species were isolated: Penicillium
aethiopicum, Penicillium echinulatum, Penincillium oxalium,
Penicillium camemberti, Penicillium corylophilium and
Penicillium funculosum. Other fungi isolated from the
compost were Eurotium herbariorum and Fusarium species.
Storm (1985) also observed similar results, that is that the
number and diversity of microorganisms are more when two
Nature & Faune Volume 30, Issue No. 1
60
or more wastes are used for composting. Rabia et al. (2007)
have reported the highest fungi load and number of species
of Aspergillus and Penicillium in compost. Giovana et al.
(2005) also reported that Fusarium is found in compost and
was responsible for mineralization. Despite the unnoticed
role of fungi during decomposition, it is evident from this
experiment that fungi, especially Aspergillus and Penicillium
are important organisms during composting.
Conclusion
The compost is rich in plant nutrients and can be used to
ameliorate soil for crop production. Compost is high in organic
matter, nitrogen, phosphorus, potassium and other nutrient
elements which makes it suitable for the improvement of soil
quality and crop production. This method can be practised by
local farmers to ameliorate soil for sustainable crop
production. It is obvious that these agricultural waste can be
composted and used as fertilizer also the fungi genera
isolated from the compost were Aspergillus, Penicillium,
Fusarium and Eurotium.
References
Albaladejo J, Garcia C, Ruiz-Navarro A, Garcia-Franco N and
Barbera G. G., 2009. Effects of Organic composts on Soil
Properties: Comparative Evaluation of Source- separated and
Non Source – separated Composts.
Giovana, C.V., Antonella, A. and Valeria, F.M., 2005. Isolation
and identification of fungal community in compost and
vermicompost. Mycologia 97: 33-44.
IITA., 1979 . Selected methods for soil and plant analysis.
International Institute for Tropical Agriculture, Ibadan. Manual
series, No. 1
Jambhekar H., 2002. Vermiculture in India-Online training
material. Purie, India Maharashtra, Agricultural Bioteks.
Jacobs R.D; Sloan, D., and Jacob J 2003. Cage Layer Manure:
An Important resource for Land Use,
http://edis.ifas.ufl.ued/ps005. Retrieved 16 /10/ 2014.
Lindsay, W. L, Norvell W. A., 1978. Development of a DTPA soil
test for zinc, iron, manganese and copper. Soil Science
Society of America Journal. 42: 421 – 428.
Michel, F.C., Forney, L.J., Huang, A.J., Drew, S., Czuprenski, M.,
Lindeneg, J.D., Reddy C.A.,1996. Effects of turning frequency,
leaves to grass ratio and windrow vs pile configuration on
composting of yard trimmings. Compost Science Utilization.
4:26 43.
Nelson, D. W. and Sommers, L. E., 1975. A rapid and accurate
method of estimating organic carbon in soil. Proceeding of
Indiana Academy of Science. 84:456-462.
1st Spanish National Conference on Advances in Materials
Recycling and Eco – energy Madrid, 12-13 November 2009
S02-10
Ohtaki A. and Nanasaki, K., 2002 A sample numerical model
for predicting matter decomposition in a fed. Bateh
composting operation. Journal of Environment quality
31:997-1003.
Anderson J. M and Ingram. J. S., 1993. Tropical soil biology
and fertility. A hand book of methods. Information Press
Eynsham. 10-85.
Rabia A., Tasneem, A and Fazia, S., 2007: Association of Fungi,
Bacteria and Actinomycates with Different Compost. Pakistan
Journal of Botany 39(6): 21410215.
Bouyoucos, G.J. (1962). Hydrometer method improved for
making particle size analyses of soil. Agronomy Journal.
53:464-465.
Wipo., 2002. Compost process and techniques Canada: The
c i t y o f C a m ro s e .
Av a i l a b l e a t
http://www.camrose.com/engineering/engserv/composters.
htm.accessed March 31, 2010.
Bremner J.M, Mulvaney C. S., 1982. Nitrogen – Total. In
Methods of soil analysis, American Society of Agronomy, 9 (2):
595 – 624. Page, A. L. (Ed), Madison, Wisc. USA.
Van Zwieten L., 2009. Agro-economic valuation of biochar
using field-derived data. Conference presentation at Asia
Pacific Biochar, May 2009, Gold Coast Australia.
Edward S, Asmelash A, Araya H, Egziabher, T. B. G., 2007.
Impact of Compost Use on Crop Yield in Tigray Ethiopia Food
and Agriculture of the United Nations. Rome.
Nature & Faune Volume 30, Issue No. 1
61
Soil erodibility evaluation in Makurdi Benue
state, Nigeria
Blessing Iveren Agada1 and Martins Eze Obi2
Summary
The concern over soil improvishment and erosion problems
and specifically the problems associated with run-off and
erosion from agricultural lands led to a combination of
laboratory analysis and field simulation studies aimed at further
understanding rainfall – runoff – soil –loss relationships. The
erodibility of soils of sandstone and shale parent material were
assessed with four indices developed in temperate countries.
The indices were, “ clay ratio ”involving the hydrometer test
(Bouyoucos, 1935), “soil aggregate stability”
(Yoder,1936),use of the “nomograph” (Wischmeier et al, 1971
and “rainfall simulation”. The soils were of coarse and medium
textures(sandy loam and loamy sand). Soils of the sandstone
and shale parent material had clay ratio that were not
appreciably different(mean of 0.88 and 0.85 respectively). Soil
aggregate stability values were moderate (41 - 49%) for
sandstone derived soils and low (31-36%) for shale derived
soils indicating expectedly higher resistance to erosion for the
sandstone compared to the shale soils. Mean values of
erodibility estimates using the nomograph were 0.06 and 0.04
Mg.h.MJ-1mm-1 for sandstone and shale soils respectively and
were not significantly different. Under rainfall simulation mean
soil loss value was significantly higher in the sandstone soils
(10.75 kg m2) compared to the shale soils (3.28 kg m2). For
proper soil conservation planning, indices developed in other
regions of the world must be carefully tested to ensure local
applicability. Intensive regional network studies re required to
develop appropriate indices for modeling soil conservation in
the agro ecological region.
Introduction
Soil loss is commonly predicted using the Universal Soil Loss
Equation (USLE) of Wischmeier and Smith (1978) and its
revised forms, the Revised Universal Soil Loss Equation
(RUSLE) and the Modified Universal Soil Loss Equation
(MUSLE). The equations essentially relates soil loss to the
dynamic interaction of rainfall erosivity (R ), soil erodibility ( K),
slope steepness and length ( SL), cover management ( C ) and
support practice factor( P ).
Soil erodibility, a quantitative measure of the resistance of the
soil to both detachment and transport, is a function of soil
texture, structure, permeability, organic matter content and
the management of soil (Hudson, 1995). The soil erodibility (K)
factor of the USLE was defined by Renard et al, (1997). It may
be assessed on a scale of 0 (low erodibility or high resistance
to erosion) to 1, as with the clay ratio, or 0.1 for S.I unit, as with
the USLE nomograph (high erodibility or low resistance to
erosion) . It can be evaluated either directly using in situ
erosion plots (Wischmeier and Smith, 1978) or indirectly
(Bryan, 1968) by using the USLE nomograph (Wischmeier et
al., 1971) or simulated rainstorms (Dangler and EL Swaify,
1976). Assessment of soil susceptibility to erosion risk is a
basis for effective conservation planning. Risk assessment
requires key information on rainfall erosivity (R) and soil
erodibility (K ), information that is still sketchy for the Makurdi
area (Isikue et al.,2011).The role of soil parent material requires
clearer understanding.
An investigation was carried out to assess the erodibility of
soils derived from two parent materials in Makurdi using four
indices.
Materials and methods
Study area
The study was carried out in Makurdi Benue state, Nigeria,
0
0
located on latitude 7 41'N and longitude 08 37'E. Makurdi
experiences a tropical climate, with temperatures ranging is
0
0
from 22 C to 36 C.The relative humidity ranges from 50% to
80%. The elevation is 106.4 m. The mean annual rainfall is
about 1250 mm and the duration of rainfall is between 200
and 300 days ( Idoga et al.,2005). Field investigations were
carried out at the University of Agriculture Makurdi's teaching
and research farm as well as the student industrial work
experience scheme SIWES Farm. The soils at the research
farm were derived from shale and those at the SIWES farm
from sandstone.
Laboratory methods
The Bouyoucos (1935) hydrometer method was used for
particle size analysis of the soil. A nest of sieves was used for
sand grade analysis, required for the evaluation of K with the
USLE nomograph. Organic carbon was determined as
described by Walkley and Black (1934). Saturated hydraulic
conductivity was determined using the constant head
method of Klute (1965) and Darcy's flow equation. Soil
permeability was obtained from the results of the hydraulic
conductivity determination as discussed by O'Neal (1952).
Dry bulk density, total porosity, macro and micro porosity were
calculated. Aggregate stability was determined as described
by Yoder (1936). The percentages of water-stable aggregates
greater than 0.5 mm diameter (excluding the sand fraction)
were calculated.
1
Blessing Iveren Agada,
Soil Science Department, University of Agriculture,
P.M.B 2373 Makurdi. Benue State. Nigeria.
Tel.: (234) 8037101891.
Email: [email protected];
Email: [email protected]
2
Martins Eze Obi,
Professor of Soil Science, Department of Soil Science,
University of Nigeria Nsukka, Enugu State Nigeria.
Tel.: 234 8132293383
Email: [email protected]
Nature & Faune Volume 30, Issue No. 1
62
Field methods
Soil investigations in the field were carried out at four locations. Core samples were taken from these sites at 0-10 cm depth for
bulk density determinations. Samples were also taken at 0 -17 cm depth with a shovel for wet sieving (aggregate stability)
analysis. A portable non- pressurized rainfall simulator was constructed with dimensions of 110 cm x 210 cm (length x width)
accommodating 181 drop formers. The average drop size produced was 4.6 mm. It was set to rain at an intensity of about 250
mm h-1 to simulate near maximum reported rainfall intensity for Makurdi (Agada, 2015). Micro- plots were constructed on a soil
having a slope of about 5%. The micro-plots were 200 cm long, 150 cm wide and 30 cm deep. Water and eroded sediments were
collected at the lower outlets of the plots in bins after each run. Two duplicate test runs were performed namely, dry run and wet
run, each lasting for about 15 minutes, with about 150 L of water used.
Results and discussion
Table 1 gives the values of selected properties known to influence soil erodibility (Wischmeier and Mannering, 1969) for
sandstone and shale derived soils. The textures were coarse to medium (sandy loam to loamy sand). Bulk densities for the shale
-3
-3
-3
derived soils were in the range of 1.15 g cm to 1.35 g cm with a mean of 1.27 g cm and for soils of sandstone origin in the range
-3
-3
-3
of 1.48 g cm to 1.6 g cm with a mean of 1.55 g cm
Mean erodibility values derived from clay ratios were 0.88 and 0.85 for the sandstone and shale derived soils respectively
indicating no difference in the soils' resistance to erosion. Notably the clay ratio index places soils in a hierarchy of erodibility but
has no defining value for “erodible” and “non erodible” soils. The percentage of water stable aggregates > 0.5 mm ranged from
32% to 36% for the shale derived soil and 41% to 49% for the sandstone derived soils. According to this parameter soils of
sandstone origin (SIWES farm) were slightly more stable and thus will offer higher resistance to erosion compared to those of
shale parent material. Aggregate stability governs the ease with which large aggregates above the erosion threshold can be
broken down to sizes vulnerable to erosion( Bryan, 1968). Mean values of erodibility using the USLE nomograph were 0.04 and
0.06 Mg.h.MJ-1 mm-1 for the sandstone and shale soils respectively.. There was no clear difference between the two groups of
soils. In the rainfall simulation study actual soil loss values were much lower for the shale derived soils than for the sandstone
derived soils. Since this was the only parameter that actually measured soil loss due to erosion this must be considered to give the
real difference in erodibility between the two groups of soils. Expectedly, erodibility values were lower for the wet run as compared
to the dry run.
Table 1: Erodibility indices of the soils of the study sites according to different parameters
Location
Water stable
Clay ratio
Aggregates
USLE Nomograph
Mg.ha.h.ha-1MJ-1mm-1
Sediment yield/ Soil loss
under simulated rainfall
Mg.ha.h.ha-1MJ-1mm-1
> 0.5mm
(%)
Dry kg m2
Wet kg m2
SIWES farm Plot 1
49
0.89
0.071
0.707 (12)
0.55 (9.8)
SIWES farm Plot 2
41
0.87
0.041
0.62 (11)
0.57 (10.2)
Agronomyfarm Plot1
32
0.85
0.051
0.28 (5)
0.16 (2.8)
AgronomyfarmPlot 2
36
0.85
0.043
0.22 (3)
0.13 (2.3)
Conclusion
The inferred and calculated parameters did not give clear cut indications of the erodibilities of the different soils. The actual
empirical measurement of soil loss done by means of rainfall simulation indicated large differences between the erodibilities of
the two groups of soils. The latter is very important regarding land suitability evaluation. The study clearly indicated that indices
and norms developed elsewhere cannot be used blindly in a different type of situation.
Nature & Faune Volume 30, Issue No. 1
63
References
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in Makurdi, Benue State, Nigeria. MSc.Thesis. Department of
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Dangler, E.W and El - Swaify, S.A. (1976). Erosion of selected
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conductivity of saturated soil. In: C.A. Black(Editor -in chief),
Method of Soil Analysis. Part 1, Agronomy nomograph 9,
American Society of Agronomy. Pp. 210- 221.
O'Neal, A.M. (1952). A key for evaluating soil permeability by
means of certain field clues. Soil Science Society of America
Proceedings. 16: 312-315.
Renard K.G., Forster G.R.,Weesies G.A., McCool D.K., and Yoder
D.C.(1997). Predicting soil erosion by water: A Guide to
Conservation Planning with the Revised Universal Soil Loss
Equation (RUSLE). USDA Agriculture Handbook. No. 703.
Washington DC.
Walkely, J.T and C.A. Black (1934). An examination of the
Degtjarefft method of determing the organic matter and a
proposed modification of the chromic acid titration method.
Soil Science 37:29 -38.
Nature & Faune Volume 30, Issue No. 1
64
Role of soil in nutrition sensitive food systems
in Africa
Mawuli Sablah*1, Mohamed AgBendech1, Lamourdia
Thiombiano2 and Laouratou Dia1
Summary
Nutrition sensitive agricultural food systems require high
quality soil nutrients. This article highlights the linkages
between soil and nutrition sensitive food systems. It is
estimated that 95% of our food is directly or indirectly
produced from soils. Nutritionally balanced soils are
fundamental to sustain food systems and essential to food
security and nutrition. Soil erosion and land degradation as a
consequence of multiple factors result in fewer nutrients that
are essential to agricultural production, food quality and
nutritional value. This situation that is currently occurring
across the continent has major implication not only on food
quality and quantity but also increase the trend and risks of
under-nutrition. Maintaining and increasing soil quality is
therefore a prerequisite for reducing the risks of nutritional
deficiencies in Africa.
1.0 Introduction
M.S. Swaminathan (2014) in quoting Aristotle reiterated that
“soil is the stomach of the plant”. Nutritious and good quality
food and animal fodder can only be produced by healthy soils
to guarantee food security and nutrition. In Africa
micronutrient deficiencies have been reported for a range of
soils under differing crop production conditions. These
deficiencies can be corrected for improved soil fertility, crop
yield and nutrient density of human foods. Soil fertility is
important in regard to the quantity of food produced and the
provision of adequate quantities of micronutrients in the diet.
Central Africa for example is dominated by soils that are
inherently extremely infertile and have characteristics that
make soil fertility management extremely difficult. Many other
parts of Africa are also dominated by very poor quality soils
and unfavorable rainfall patterns; either far too high in areas
like central Africa or far too low as in the 25% of Africa occupied
by deserts (Laker 2005b).
Food systems include the entire range of activities, from tilling
soils to consumption and re-utilization of plant and animal byproducts for soil quality improvement. As part of the Food and
Agriculture Organization of the United Nation's constitutional
mandate to raise the levels of nutrition and standards of living
of all people, food based approaches to optimize nutrition are
fundamentally deployed and linked to sustainable
management of natural resources, including soils. The
challenge to the food system embodied in pressure on natural
resources, climate change, increasing population growth,
rapid urbanization, and changing lifestyles are having
profound impact on food production and the daunting task of
raising levels of nutrition.
The Rome Declaration of the Second International
Conference on Nutrition (ICN-2) held in November 2014,
jointly organized by FAO and WHO, noted with profound
concern that, notwithstanding significant achievements in
many countries, recent decades have seen modest and
uneven progress in reducing malnutrition with the prevalence
of undernourishment moderately declined, but absolute
numbers remaining unacceptably high with an estimated 805
million people suffering chronically from hunger in 20122014 (FAO/WHO 2014). According to the 2015 Global
Nutrition Report Brief on Africa the scale of malnutrition on the
continent continues to be staggering with 58 million children
under five stunted, 13.9 million wasted and 10.3 million
overweight, while 163.6 million children and women of
reproductive age are anemic; a proxy for the overall challenge
of micronutrient deficiencies. Thirteen countries in Africa are
faced with terrible challenges of managing the levels of under
5 stunting or anemia in women of reproductive age (Africa
Brief - GNR 2015). Approximately one person out of four in
Sub-Saharan Africa is estimated to be undernourished in
2015 compared to a ratio of one out of three in the early 1990s
(FAO, 2015). The region is affected by the multiple burden of
malnutrition with coexistence of several forms of malnutrition.
2.0 The value of fertile soils to sustainable nutrition
sensitive food systems
Food crops grown on fertile soils contain more micronutrients
than nutrient-stressed crops grown on infertile soils. Soil
micronutrient status, cropping systems, variety selection (i.e.,
plant breeding) for micronutrient-dense crops (e.g., biofortification) and soil fertilization practices are important
factors that impact the nutrient output of food systems. Soil
improvements increase productivity and allow for greater
diversity of crops. Sustainable soil management is therefore
critical for the production of nutritious food. In addition to
sustaining directly or indirectly 95 percent of food production,
soils host more than a quarter of the planet's biodiversity and
play a critical role in the carbon cycle (FAO 2015). At the same
time, the level of soil degradation – estimated at 33 percent
globally – is “alarming” (FAO 2015). A shortage of any one of
the 15 nutrients required for plant growth in soils can limit crop
yield and affect the nutritional value of food. By 2050,
agricultural production must increase by 60% globally – and
by almost 100% in developing countries, particularly in Africa,
in order to meet food demand. Sustainable soil management
could increase production by up to 58 percent more food
(Wall & Six, 2015).
1
Regional Office for Africa, United Nations Food and Agriculture
Organization, P. O. Box GP 1628 Accra. Ghana.
Mawuli Sablah* (Corresponding author) Regional Office for Africa,
United Nations Food and Agriculture Organization,
P. O. Box GP 1628 Accra. Ghana.
Tel.: (233) 302 675000 Extension 41607. Fax: 233 302 668 427 , Email :
[email protected]
2
Lamourdia Thiombiano PhD, Soil specialist. FAO, Sub Regional
Coordinator for North Africa; FAO Representative to Tunisia 43 Rue
Kheireddine Pacha, Belvédère TUNIS .
Mailing Address: P. O. BOX 300, 1082 Citè Mahrajène, Tunis Tunis .
Telephone: +216-71-906553 ; +216 71 903 396 Fax: +216-71-901859
Email: [email protected]
Website: http://www.fao.org/neareast/
Nature & Faune Volume 30, Issue No. 1
65
In the case of zinc, a micronutrient essential for growth and
maintenance or gene expression, tolerance to environmental
stress conditions results in higher requirements of Zn to
protect cells from the detrimental effects of stress. This
micronutrient deficiency appears to be the most widespread
and frequent in crop and pasture plants worldwide, resulting
in severe losses in yield and nutritional quality. This is
particularly the case in areas of cereal production. It is
estimated that nearly half the soils on which cereals are grown
have levels of available Zn low enough to cause Zn deficiency
(Alloway, 2008). Zinc deficiency in soils can be absolute or
induced. Absolute deficiency is related to the parent material,
texture, degree of weathering and/or pH and calcareousness
of a soil. Induced deficiency is mainly due to injudicious liming,
injudicious phosphorus fertilization or removal of topsoil
(Laker 2005a).
Since cereal grains have inherently low bio-available Zn
concentrations and growing them on potentially Zn-deficient
soils further decreases grain Zn concentration (Cakmak
2007). Well -documented Zn deficiency problems in humans
occur predominantly in the African regions where soils are low
in available Zn and cereals, root and tubers are the major
source of calorie intake (Laker 2005a). Zinc-deficient soils may
remain undetected for many years unless soil or plant
diagnostic tests are carried out, because there are no obvious
early signs of stress in the crops growing on them (Alloway,
2008).
3.0 Maintaining good soil quality to sustain
biodiversity and optimal nutritional value
The consciousness of human beings to their utter
dependence on soils and the implication of soil degradation
to their nutritional survival impel them to adapt to mitigate the
negative effects of climate and environmental conditions to
soil quality and fertility. In re-configuring the sustainable value
of soils, there is increasing advocacy for agro-ecology; organic
farming, conservation agriculture with zero tillage to ensure
the natural balance of soil nutrient fertility with soil
microorganism and fauna, agro-forestry eco-systems for
crops, trees and animal production, resulting in the
sustainable management of soils to produce more diversified
and healthy nutritious foods. Faster bio-organic
decomposition and biomass soil growth would create much
more fertile soils, which will lead to increase in crop yield and
outputs of nutrient dense or bio-fortified crops being
promoted in Africa.
The diversity of species used for food has diminished
drastically over the years and most people now depend on
three main cereals, namely maize, rice and wheat, which
combined provide over 50% of the global food energy intake
and with only 12 other crops and animal species altogether
providing over 75% of the world's food today (FAO, 2012). The
nutritional quality of food is highly compromised with
increasing trends in high consumption of sugar, salt and ultraprocessed fat coupled with low physical activity,
micronutrient deficiencies, linked to poor quality nutrient
deficient soils and the multiple burden of malnutrition.
high quality
fertile soils
ideal climate
environment
& weather
Nutritious
food
production
good
agricultural
practices and
inputs
post harvest
management
& processing
Figure 1: Elements linked to sustainable nutritious food
production
Whereas various studies have consistently associated
increasing dietary diversity to micronutrient density of the diet
both in infants and women using indigenous foods, most
indigenous foods are now being underutilized or inaccessible
due to reducing biodiversity and soil degradation. Nutrition
sensitive agricultural food systems therefore require high
quality soils for producing and ensuring dietary diversity in
combination with appropriate care practices, water and
sanitation for good nutrition and health. This aligns directly
with the second SDG of linking food systems and sustainable
agriculture through food-based approaches to nutrition.
4.0 Conclusion and international action for
nutritionally sustainable food and soil systems
The Rome Declaration of the ICN-2 recognizes the need to
address the impacts of climate change and other
environmental factors on food security and nutrition, in
particular on the quantity, quality and diversity of food
produced and taking appropriate action to tackle their
negative effects, particularly on soil fertility. It also
acknowledges that current food systems are being
increasingly challenged to provide adequate, safe, diversified
and nutrient rich food for all that contribute to healthy diets
due to, inter alia, constraints posed by resource scarcity and
environmental degradation, as well as by unsustainable
production and consumption patterns, food losses or waste,
a n d u n b a l a n c e d d i s t r i b u t i o n ( FAO / W H O 2 0 1 4 ) .
Recommendations 10 and 12 of the framework for action of
the Rome Declaration therefore seeks to promote the
diversification of crops, including underutilized traditional
crops, more cultivation of fruit and vegetables, and
appropriate production of animal-source foods while
applying sustainable food production and natural resource
management practices including effective soil management
to enhance the resilience of the food supply system, including
areas affected by climate change (FAO/WHO 2014).
Nature & Faune Volume 30, Issue No. 1
66
In taking international action, concrete steps are required to
characterize and manage land areas for fertile soils capable of
sustaining two to three good crops a year; declared as Special
Agricultural Zones (SAZ) with soil health monitoring and
amelioration centers. These centers could assist farmers with
soil health cards with extension services on good farming
practices and assistance to rectify soil defects, such as salinity,
alkalinity and water logging challenges. Special attention
could be paid to soil organic matter since this is essential for
improving the micronutrient content, hydraulic conductivity,
chemistry and microbiology of the soil. There is the need to
popularize local level soil health assessment systems such as
the presence of earthworms and nitrogen fixing and
phosphorus solubilizing microorganisms. These could be
coupled with local level soil health managers to support both
soil health monitoring and nutrient amelioration. If we do not
attend to soil nutritional value and improvement, we will not be
able to achieve human nutritional value and therefore the goal
of ending hunger and malnutrition in Africa by 2025.
References:
Alloway B. J. 2008. Zinc in soils and crop nutrition, Second
edition, published by IZA and IFA Brussels, Belgium and Paris,
France, pp 10 -11
Global Nutrition Report 2015. Africa brief; action and
accountability to advance nutrition and sustainable
development. Launched at the 2015 Africa Day for Food and
Nutrition Security (ADFNS 2015), Kampala, Uganda.
International Food Policy Research Institute. 2015. Global
Nutrition Report 2015: Actions and Accountability to Advance
Nutrition and Sustainable Development 6: pg 75-84
Kiekens, L.,1995. Zinc, in Alloway, B.J. (ed.) Heavy metals in
soils (2nd edn.). Blackie Academic and Professional, London,
pp 284-305.
Laker, M.C. 1967. Effect of previous applications of lime and
zinc on the subsequent uptake of phosphorus and fertiliser
zinc by rye plants in a pot experiment. S. Afr. J. Agric. Sci., 10:
11–18.
Laker, M.C. 2005a. The global impact of zinc micronutrient
deficiencies. Proc. Combined FSSA & SASRI Symposium on
Micronutrients in Agriculture: Demands of Subtropical Crops,
Mt. Edgecombe. FERTASA, Pretoria, South Africa.
Laker, M.C. 2005b. Appropriate plant nutrient management
for sustainable agriculture in Southern Africa.
Communications in Soil Sci. and Plant Anal. 36, 89-106.
Batiomo A., Hartemink A.,Lungo O., Naimi M., Okoth P.,
Smaling E., and Thiombiano L. 2006. African Soils: Their
productivity and profitability of fertilizer use. Background
paper prepared for the African Fertilizer Summit; Abuja
Nigeria.
Osborn D., Cutter A. and Ullah F. 2015. Universal sustainable
development goals Understanding the transformational
challenges for developing countries. Report of a study by
stakeholders.
Cakmak, I., 2007. Enrichment of cereals grains with zinc:
Agronomic and genetic biofortification. Plant and Soil, DOI
10.1007/s11104-007-9466-3.
Smaling, E.M.A. (1993) The soil nutrient balance: And
indicator of sustainable agriculture in sub-Saharan Africa.
Peterborough, UK; Fertiliser Society Proceedings – Fertiliser
Society No. 340, pp. 1–18.
FAO 2012,. Sustainable diets and biodiversity directions and
solutions for policy, research, and actions. International
Scientific Symposium “Biodiversity and Sustainable Diets:
United Against Hunger” organized jointly by FAO and
Biodiversity International, held at FAO, in Rome, from 3 to 5
November 2010.
Swaminathan M. S. 2014. Importance of Soil in achieving Zero
H u n g e r
C h a l l e n g e ,
http://www.mssrf.org/?q=content/importance-soilachieving-zero-hunger-challenge
FAO 2015. Regional Overview of Food Insecurity Africa
African, on the state of food insecurity in Africa (SOFI) 2015.
African food security prospects brighter than ever.
FAO 2015., Healthy soils are the basis for healthy food
production
FAO/WHO, 2014. Second International Conference on
Nutrition - Framework for Action; from commitments to action.
FAO/WHO, 2014. Second International Conference on
Nutrition - Rome Declaration on Nutrition.
Van der Waals J. H. and Laker M.C., 2008. Micronutrient
Deficiencies in Crops in Africa with Emphasis on Southern
Africa. In Micronutrient Deficiencies in Global Crop
Production; B.J. Alloway (ed.), Springer Science + Business
Media B.V.
Wall, D. H. and Six J, 2015. Sciences Editorial on “Give soils
their due”. VOL 347 ISSUE 6223
Welch, R. M.; Graham, R. D. Cakmak, I. 2013 Linking
Agricultural Production Practices to Improving Human
Nutrition and Health; FAO/WHO
Nature & Faune Volume 30, Issue No. 1
67
The importance of sustainable land
management for food security and healthy
human nutrition in central Africa
Ousseynou Ndoye1
Introduction
Among the overarching objectives of governments in Central
Africa, poverty reduction, food security and nutrition are very
important goals. This is confirmed by the fact that countries in
Central Africa have defined poverty reduction strategies.
Furthermore, in June 2014, an important meeting of the
African Union (AU) on food security and nutrition was held in
Malabo, Equatorial Guinea and African leaders and their
international allies such as The Food and Agriculture
Organization of the United Nations (FAO), The United Nations
Development Program (UNDP), The World Bank (WB) made
important decisions for the future of the continent. In May
2013, FAO organized an international conference on forests
for food security and nutrition which was widely attended. In
November 2014, FAO and The World Health Organization
(WHO) organized another international conference on
nutrition, which showed the continuous commitment of the
organizations to fight poverty and hunger. At the regional
level, the Forestry Commission of Central Africa (COMIFAC)
has elaborated in 2013 a program on forests for food security
and nutrition in Central Africa. In September 2015, in Durban
in South Africa, the issue of food security and the role forests
and trees can play stood out very strongly in the agenda and in
the discussions in plenary and parallel sessions. Under this
context, sustainable land management has an important role
to play in achieving food security and nutrition.
It is argued in this paper that to reconcile land management
and food security, governments of Central Africa should
allocate more forests to local communities' management to
improve their food security and to increase investment in
agricultural and forestry research aimed at producing
improved varieties of agricultural and forest products which
will allow farmers to stay longer in a given piece of land
without having yield losses.
The second section of the paper discusses the dimensions of
food security. Section 3 discusses food security and
sustainable land management. The implications of land
management for food security are discussed in section four.
The last section provides few concluding remarks.
Dimensions of food security
Food security is assured when all individuals at all times have
economic, social and physical access to enough food, which
satisfy their nutritional requirements and food preferences for
an active and healthy life (FAO, 2014). Food security has four
pillars: availability, access, utilization and stability. According
to the definition, the nutritional aspect is embedded in the
concept of food security. Food security has both supply and
demand dimensions. Supply relates to the provision of
agricultural and forest products after harvesting of crops or
collection from forests for direct home consumption. The
demand side refers to the need for agricultural and forest
products to be marketed and to purchase food from the
revenues received. Another dimension of supply relates to the
direct use of medicinal plants to improve human health and
thus increase labour productivity in agriculture. This shows
the complementarity between agriculture and forest at the
household level (Ndoye and Asseng Ze, 2015). For example,
in the Senanga district of Zambia, as study by Kwaw-Mensah
(1996) showed that farmers rated poor human health as the
most important factor responsible for low agricultural
productivity in the district.
At the macro level it should inspire and motivate intersectoral
collaboration between ministries in charge of agriculture and
those in charge of forests and the environment.
Sustainable land management and food security
Sustainable land management is very important in achieving
food security and efficient nutrition. This is because the supply
and the demand sides of the food security equation need to
be balanced by means of appropriate land use arrangements:
primary forest, secondary forest; fallows, home gardens,
agricultural land, forest concessions, community forests, and
communal forests. Furthermore, improved infrastructure
(roads and transport services) is required to enable efficient
movement of forest and agricultural products to markets
where buyers purchase the products they want to consume
while sellers dispose of their products to get revenues, which
will enable them to purchase other food items. Markets which
facilitate these transactions are located in rural, semi-urban
and urban areas.
Tenure security is very important in strengthening the
relationship between sustainable land management,
appropriate land use and food security. When actors feel
secure in their ownership of land and forests, they will be
willing to provide additional investments in those resources.
This can facilitate reforestation of degraded land with trees of
economic values; it also facilitates the adoption of
agroforestry technologies (domestication) and more planting
of trees in the agricultural landscape.
1
Ousseynou Ndoye,
Chief Technical Advisor, Non wood Forest Product(NWFP) project,
Food and Agriculture Organization of the United Nations (FAO)
Subregional Office for Central Africa (SFC); Immeuble Bel Espace
Batterie IV 2643 LIBREVILLE,
P. O. Box 2643 Libreville, GABON.
Email: [email protected]
Telephones: +241 01774783; +241 07641164; +241 01741092
Web address: www.fao.org/africa/central
Nature & Faune Volume 30, Issue No. 1
68
Implications of land management for food security in central Africa
Central Africa is in this paper defined as consisting of the countries indicated in Table 1. It is home of the second largest
contiguous forest in the world after the Amazonia, and for that reason it is an important reservoir of biological diversity. Around 70
million persons exploit these resources to satisfy their subsistence needs, income generation and employment. Non Wood
Forest Products (NWFP), which are a major component of the biological diversity, are edible and medicinal plants, bush meat,
insects, honey, rattan and other fibres for building shelter or tools. In addition, the forests of Central Africa provide ecosystem
services, including biodiversity protection, and they possess great cultural, religious and aesthetic values for the people of the
region. Therefore, the well-being of rural people is affected by all forms of development that impact the forests.
Forest is allocated for timber exploitation, for agricultural production (slash and burn agriculture, industrial plantations, livestock,
fisheries and aquaculture), community forestry exploitation, mining, infrastructure development, and biodiversity conservation
(protected areas). In forest concessions, traditional hunting and the collection of NWFP are authorized to enhance food security
and nutrition of rural populations. These efforts made by timber companies are extremely important but they are not enough if
the Forestry Commission of Central Africa (COMIFAC) sub regional guidelines on NWFP are to be implemented. These
guidelines recommend the adoption of commercial use rights for NWFP that are not threatened. It means that in addition to using
NWFP for home consumption, the commercial use right allows communities to sell or exchange NWFP that are not threatened.
Table 1 shows that the area under protected areas differs widely between different countries in Central Africa. In COMIFAC
countries, the lowest percentage of national territory devoted to protected area management is found in Burundi (5.14%) while
the maximum is found in Sao Tome and Principe (29.47%).
Table 1. Percentage of the territory allocated to protected areas in different Central African countries
Country
Burundi
Area in protection (km2)
Area in protection as % of
total territory
1433
5.14
Cameroon
38250
8.05
Central African Republic
70145
11.25
Congo
39924
11.67
DRC
264157
11.26
34595
11.91
Equatorial Guinea
5910
21.11
Rwanda
2354
8.93
295
29.47
Gabon
Sao Tome and Principe
Chad
113678
8.85
Source: RAPAC/OFAC/COMIFAC 2015
In protected areas, rural communities are not allowed to enter and collect forest products. In Burundi, despite the protection of
parks and reserves, women and other indigenous population members enter the reserves illegally to get forest products for their
survival needs. If they are caught, they are beaten by forest eco-guards or put in jail. Food security and nutrition are threatened
under these conditions. In principle, the policy guiding the management of protected areas is the same in other countries of
Central Africa. Protecting forest biodiversity is important and should always be a major goal that needs to be pursued to reduce
Nature & Faune Volume 30, Issue No. 1
69
green-house emissions, and to sequester more carbon and
reduce the negative effect of climate change. However,
human beings should be put in the fore front within the forest
landscape of Central Africa, especially in a region where there
is acute poverty and serious development challenges (FAO,
2015).
Mining activities are also getting more important in Central
Africa. One issue that needs more attention is the
superposition of areas allocated for mining and those
allocated to timber exploitation or between areas allocated for
protection and those allocated for mining (Oyono et al., 2013).
A conflict arises between the short term creation of job
opportunities and income from timber exploitation and mining
activities on the one hand and the long term negative impacts,
often irreversible, that these have on food security and
nutrition and the environment. Policy makers in Central Africa
need to address this problem in countries where these
conflicts are likely to take place.
Another development since 2007 is land grabbing which has
become an important issue in Africa. It is a lease between 30 to
99 years or a transfer of land ownership to foreign investors
facilitated by the government. In the Democratic Republic of
Congo, 3 million hectares of land were granted to China for the
production of biofuels when the country has 71 percent of its
population being food insecure and where only 7 million
hectares are currently cultivated (Laker, 2013). Furthermore,
importing food is expensive due to bad or inexistent roads
(http://www.grain.org/article/entries/4575-land-grabbingand-food-sovereignty-in-west-and-central-africa). In
Cameroon, in 2006, 10000 hectares on a 99 year lease were
given to a subsidiary of the Shaanxi Land Reclamation General
Corporation (http://www.grain.org/article/entries/4575-landgrabbing-and-food-sovereignty-in-west-and-central-africa).
In Congo, South African groups obtained 80000 hectares
from the government under a 30-year lease to grow rice, corn
and soybean. Furthermore, a concession of 470000 hectares
was granted to a Malaysian company to produce oil palm
causing lot of damages to local livelihoods
(https://www.grain.org/article/entries/4575-land-grabbinga n d - f o o d - s o v e re i g n t y - i n - w e s t - a n d - c e n t r a l - a f r i c a ) .
Fortunately, there are examples in Madagascar, Ethiopia and
Uganda where local communities did not accept to be
dispossessed with their customary rights and successfully
opposed it .
Community forestry has also grown in importance in Central
Africa, especially in Cameroon, Gabon and Democratic
Republic of Congo (Karsenty et al., 2010). They provide an
opportunity to village associations to legally harvest, process
and trade timber (Lescuyer et al., 2015) in order to improve
their livelihood and food security. Most of the current focus is
on timber, although there is a need to include the exploitation
of NWFP as an option to diversity the livelihood opportunities
of communities. COMIFAC has recently organized a regional
meeting which recommended a better inclusion of economic
and social particularities of community forestry in the legal
framework of countries in Central Africa (COMIFAC, 2015).
With a growing population in Central Africa, there is increasing
pressure for land use expansion, but at the expense of the
forest which will not be sustainable. The following actions are
therefore needed to reconcile sustainable land management
and food security and nutrition in Central Africa:
Ÿ
There is a need for more investment in agricultural
research (crops, forestry). This will promote the
availability of high yielding adapted cultivars of crops
and forest products which will adapt to climate
change. The governments of countries in Central
Africa have an important role to play by honouring the
allocation of 10 percent of the countries' budget for
agriculture as committed in 2003 in Maputo (Mwape,
2009).
Ÿ
Appropriate innovative agricultural practices, resulting
from technological breakthroughs from agricultural
and forestry research, should be developed and
implemented in rural areas. For example, it will be good
to readjust the agricultural calendar to cope with the
development of new improved cultivars. The periods
for timely planting, weeding and harvesting should be
communicated to farmers in order to enable them to
maximize their production.
Ÿ
Governments of Central Africa should increase the
area of forests allocated to community management.
This will improve the livelihood and revenues of men,
women, youth and indigenous communities.
Ÿ
Tenure policy is very important in Central Africa. There
is a need to ensure that local communities have secure
access to forest resources by paying particular
attention to women. For that reason the adoption of the
FAO voluntary guidelines on the Responsible
Governance of Tenure of Land, Fisheries and Forests in
the context of National Food Security needs to be
implemented by countries in Central Africa.
Conclusion
As shown in the paper, sustainable land management is very
important to strengthen food security and nutrition in Central
Africa. Policy makers have a crucial role to play at a moment
where the expenditures on food imports are affecting heavily
the terms of trade of countries in Central Africa. For that reason,
more investments in agricultural and forestry research are
needed to reverse this trend for the well- being of the
population and the environment.
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Doumenge, C., Palla F., Scholte P.,Hiol Hiol F. & Larzillière A;
(Eds.), 2015. Aires protégées d'Afrique central-Etat 2015.
OFAC, Kinshasa, République Démocratique du Congo et
Yaoundé, Cameroun : 256 p.
Faustin Mwape (2009). How are countries measuring up to
Maputo declaration? CAADP policy brief, June.
Karsenty A., Lescuyer G.), Ezzine de Blas L, Sembres T,
Vermeulen C. (2010). Community forests in Central Africa:
Present hurdles and prospective evolution. Workshop on
Taking Stock of Smallholder and Community Forestry: Where
do we go from here? March 24-26, Montpellier, France.
Kwaw-Mensah, D. 1996. Causes of low agricultural
productivity in the Senanga district of Zambia. MInstAgrar
dissertation, Univ. Pretoria, Pretoria, South Africa. 151 pp.
Laker, M. C. (2013). Soil fertility in Sub Sarahan Africa and
effect thereof on human nutrition. Paper presented at annual
congress of the Fertilizer Society of South Africa, Durban,
June. (Available from FERTASA)
Lescuyer, Guillaume, Paolo Cerutti, Raphaël Tsanga (2015).
Promoting small-scale logging in Cameroon: is community
forestry the right target? Paper presented at the 14th World
Forestry Congress, Durban, South Africa.
Ndoye Ousseynou and Armand Asseng Ze (2015). The
Contribution of Non Wood Forest Products to Food Security
and Nutrition in Central Africa: Challenges and Policy
th
Implications. Paper presented at the 14 World Forestry
Congress, Durban, South Africa.
Oyono et al. (2013). Affectations et utilisations des terres
forestières ; Evolutions actuelles, problèmes et perspectives ;
Etats des forêts 2013
https://www.grain.org/article/entries/4575-land-grabbingand-food-sovereignty-in-west-and-central-africa
Nature & Faune Volume 30, Issue No. 1
71
Human impacts on sustainable land
management in game parks: findings based
on research in the Kruger national park, South
Africa, and reconnaissance studies in
Serengeti national park, Tanzania.
Gerhard Nortjé1
Summary
There is no doubt that food security is under threat in Africa
and the world today. There is also much saying going around
that Africa can feed the world. But is this true within the
background of the vulnerability and low resilience (recovery
potential) of much of Africa's soil resources to human impact?
Vulnerability to human impacts and low resilience are
especially true regarding the soils of southern Africa and
specifically South Africa. It is said that if the world is in
environmental extremes today it is more through the rapid
physical and chemical changes to our soils and the rapidly
changing of our air and water. The rapid rate at which our
surface soil is being lost by erosion, surface crusting and subsoil compaction is a major threat to our very existence.
Introduction
Soil is a non-renewable (finite) resource, meaning its loss and
degradation is not recoverable within a human lifespan. As a
core component of land resources, agricultural development
and ecological sustainability, it is the basis for food, feed, fuel
and fibre production, and for many critical ecosystem
services. Soil is, therefore, a highly valuable natural resource,
yet it is often overlooked. The natural area of productive soils is
limited – it is under increasing pressure of intensification and
competing uses for cropping, forestry, pasture / rangeland
and urbanization, and to satisfy demands of the growing
population for food and energy production and raw materials
extraction (Laker, 2005). Soils need to be recognized and
valued for their productive capacities as well as their
contribution to food security and the maintenance of key
ecosystem services.
Soil degradation is caused by unsustainable land uses and
management practices. About 33% of land in the world is
moderately to highly degraded due to erosion, salinization,
compaction, acidification and chemical pollution of soils. The
current rate of soil degradation threatens the capacity of
future generations to meet their most basic needs. There is
little opportunity for expansion in the agricultural area in the
world, except in some parts of Africa and South America
(Laker, 2005).
Much of the additional available land is not suitable for
agriculture, and the ecological, social and economic costs of
bringing it into production will be very high. South Africa's soil
resources are highly susceptible to sub-soil compaction and
crusting (Laker, 2005). They also are characterized by low
resilience (recovery potential). This means that even small
mistakes in land use planning and land management can be
disturbing, with little chance of recovery once the
degradation has been caused. Sustainable management of
the world's agricultural as well as rangeland soils and
sustainable production have, therefore, become imperative
for reversing the trend of soil degradation and ensuring
current and future global food security.
With regards to human impacts on our soil resources, it is not
just management for agricultural production, that is
important, but also recreational impacts on our soils in
protected areas. Recreational off-road driving (ORD) is on the
increase in protected areas in Africa (Nortjé, 2014). The main
reason for recreation in protected areas is to increase revenue
through ecotourism for conservation (Nortjé et al, 2012). But
these activities have serious long-term detrimental impacts
on sub-soil compaction, surface crusting and vegetation
(grass) recovery (Nortjé et al, 2012).
The impacts of ORD in Africa have been studied by, amongst
others, Nortjé (2014), Bhandari (1998), Onyeanusi (1986) and
Daneel (1992). ORD has been practised in the Masai Mara
Reserve, in Kenya, and the Serengeti National Park (SNP), in
Tanzania, for a long time (Bhandari, 1998; Onyanusi, 1986),
but was only recently (2001) officially introduced in the Kruger
National Park (KNP), in South Africa (Nortjé, 2014).
Discussion and conclusions
A recent visit to the SNP was a dream come true. Everything
one reads and sees of the Serengeti is true. This is the KNP,
only on a much larger scale, without fences and telephone
lines. One easily sees hundreds of thousands of wildebeest
on a game drive of three hours (Figure 1). The section of the
park that was visited, one would describe as grassland
savannah - vast grasslands, dotted here and there with thorn
trees (Figure 2) and granite inselbergs (Figure 3).
1
Gerhard Nortjé,
Technical Manager.
South African Subtropical Growers' Association.
Telephone: +27 15 307 3676
Fax: +27 15 307 6241
Email: [email protected]
Nature & Faune Volume 30, Issue No. 1
72
(Figure 5) and ORD (Figure 6). Apparently, the large migratory
herds of wildebeest are not the cause of the overgrazing
problems. They migrate in a circle pattern, thus causing a
typical pressure grazing scenario (non-selective pressure
grazing) for a very short time, followed by long enough
recovery time. Selective grazing by Masai cattle causes the
problem.
Figure 1: Wildebeest on the Serengeti plains
Figure 4: Escourt soil form - S.A. (Solonetz - WRB), with large
prisms visible
Figure 2: Thorn trees on the plains
Figure 5: Soil and vegetation degradation because of Masai
cattle overgrazing
Figure 3: Granite inselbergs
The soils in the Serengeti are characterized by extremely
unstable 'Solonetz' soils in the valley floors- the Estcourt soil
form in South Africa. The gigantic prisms are striking (Figure 4).
These soils are naturally extremely susceptible to degradation
due to human activities, such as overgrazing by Masai cattle
Figure 6: Soil degradation because of recreational off-road
driving (ORD).
Nature & Faune Volume 30, Issue No. 1
73
Recommendations and suggestions
It is very important to manage soils in Africa for agricultural,
rangeland and conservation purposes sustainable. In order to
do this, what is required is proper land use planning and in
which soil surveying and land suitability assessments should
play a major role. Delineation of soils with regards to
appropriate sustainable land uses and management is also in
protected areas are very important, just like for agricultural and
other land uses. ORD has been proven to be an ecologically
non-sustainable practise and should, if possible, not be
allowed on any land. If it is not possible to totally stop ORD, the
following recommendation should be followed:
Ÿ
Eliminate bare soil: manage the protected area in such
way as to never allow overgrazing or unnecessary ORD;
Ÿ
Controlled traffic: fewer vehicle passes caused less
compaction than more vehicle passes on the same
tracks, but most compaction occurred during the first
pass. Thus, driving in the same tracks more than once is
less damaging than driving once on different tracks.
'Controlled traffic' could solve this problem and should
be considered when developing management
strategies for ORD in wildlife protected areas;
Ÿ
Ÿ
Ÿ
Design/re-design better planned road networks
according to a soil sensitivity map: this could allow
excellent animal sightings, without the necessity to
drive off-road;
Lower tyre pressures should be considered when
driving off-road for any purpose. No driving on wet soil
should be considered, although it has been proven that
any vehicle driving off-road also cause soil compaction
on dry soils;
Ramsar pans, Vlei areas, Soils with Prismatutanic Bhorizons (so-called 'sodic' sites), Silt-loam soils and soils
with high fine sand + silt contents, Sandy soils with less
than 15% clay content, Barren areas with no grass
cover.
References
Bhandari, M.P. 1998. Assessing the impact of off-road driving
on the Masai Mara National Reserve and adjoining areas,
Kenya. Masters dissertation, International Institute for
Aerospace Survey and Earth Sciences (ITC), The
Netherlands.
Daneel, J.L. 1992. The impact of off-road vehicle traffic on the
gravel plains of the central Namib Desert, Namibia.
Unpublished MSc thesis. University of KwaZulu-Natal, South
Africa.
Laker, M.C. 2005. South Africa's soil resources and sustainable
development. Report for Dept Environ Affairs, South Africa.
Nortjé, G.P. 2014. Studies on the impacts of off-road driving
and the influence of tourists' consciousness and attitudes on
soil compaction and associated vegetation in the Makuleke
Contractual Park, Kruger National Park. Unpublished PhD
Thesis, Centre for Wildlife Management, University of Pretoria.
Nortjé, G.P.; van Hoven, W. and Laker, M.C. 2012. Factors
affecting the impact of off-road driving on soils in an area in the
Kruger National Park, South Africa. Environmental
Management 50/6:1164-1176.
Onyeanusi, A.E. 1986. Measurement of impact of tourist offroad driving on grass-lands in Masai Mara National Reserve,
Kenya: a simulation approach. Environmental Conservation,
13/4, 325-329.
The following areas should be avoided at all costs:
Nature & Faune Volume 30, Issue No. 1
74
A meta- analysis of climate change mitigation
potential of trees/forest, afforestation and
woody perennials through soil carbon
sequestration in Africa
Oladele O. Idowu1 and Ademola K. Braimoh2
Summary
This paper presents the results of a meta- analysis of climate
change mitigation potentials of trees/forest, afforestation and
woody perennials through soil carbon sequestration in Africa.
A review of the scientific literature on soil carbon sequestration
in Africa was carried out to assess the greenhouse gas
mitigation potential of different agricultural land management
activities using on-line scholarly and scientific databases as
well as more general search engines such as Google.
Estimates of the meta-analysis of soil carbon sequestration
rates were converted to net climate mitigation benefits
(abatement rates) by converting the C sequestration rates to
carbon dioxide equivalent and adjusting for emissions
associated with the land management technologies. The
results show that woody perennials have the highest climate
change mitigation potential with 4.99and 7.53tCO2eha-1 yr-1
respectively. This is followed by the trees/forest 6.69tCO2eha-1
yr-1.
Introduction
Africa, the second largest continent, has a wide diversity of
climates, ecosystems and soil conditions (FAO, 2005).
Farming systems in Africa have been evolving towards landuse intensification in response to population growth and the
scarcity of land suitable for long-fallow shifting cultivation.
Input intensification will be increasingly important in densely
populated areas. Evidence suggests that heavy investments
in soil fertility restoration will be required to create the
conditions for profitable and sustainable intensification
(Tittonell and Giller, 2013). According to UNEP's report on
Global Assessment of Human-Induced Soil Degradation
(GLASOD) some 494 million ha soil has been degraded in
Africa, due mainly to deforestation, overgrazing, agricultural
mismanagement, and over exploitation (Oldeman et al.,
1991). Overgrazing (49%) and agricultural mismanagement
(24%), together 73% (nearly three quarters) are the main
causes of soil degradation in Africa. Water erosion (46%) and
wind erosion (38%), together 84%, are the main types of soil
degradation in Africa. These degraded systems should be
managed judiciously and appropriately to reduce carbon
emissions and increase carbon sinks in vegetation and soil,
thus contributing to global climate change mitigation
(WBBGU, 1998). The Green House Gas (GHG) mitigation
potential of Sustainable Land Management (SLM) in
agricultural lands is very large (Liniger, et al 2011, Kaczan,
Arslan and Lipper 2013, Branca, McCarthy, Lipper and
Jolejole 2011), but if not managed judiciously and
appropriately can have major negative impacts that may
outweigh the benefits from carbon sequestration. In humid
tropical zones of Africa, retaining shade and understory trees
in cacao, for example, can provide vast carbon stores. Mature
cacao agroforestry systems in Cameroon store 565 tons of
CO2eq per hectare in the soil. Even in semi-arid lands,
agroforestry systems such as intercropping and silvo-pastoral
systems, with 50 trees per hectare, can store 110 to 147 tons of
CO2eq per hectare in the soil alone (Liniger, et al 2011). Forest
and plantation ecosystems management practices can play a
significant role in climate change mitigation by sequestering
carbon through photosynthesis (Strassburg et al., 2009;
Guariguata et al., 2008); However, in South Africa the main
impact of forest plantations, planted in the higher rainfall
upper parts of catchments, is to drastically reduce the amount
of runoff. In some cases perennial rivers become seasonal
rivers. This has serious implications for communities, towns,
farmers, industries, conservation areas in drier areas
downstream which/who are dependent on the runoff from
these areas. Afforestation also increases the soil erosion
hazard and leads to soil physical degradation in the form of
soil compaction (Department of Environmental Affairs and
Tourism 2006). The focus of this paper is on soil carbon
sequestered from different land management practices
associated with trees/forest, afforestation and woody
perennials. This is predicated on the fact that the IPCC (2007)
stated that a large proportion of the mitigation potential of
agriculture (excluding bio-energy) arises from soil carbon
sequestration, which has strong synergies with sustainable
agriculture and generally reduces vulnerability to climate
change. Soil carbon sequestration, according to the IPCC's
scientific advisors on land use, represents 89% of agriculture's
greenhouse gas mitigation potential. However, important
decisions on agricultural and climate policy are being made
without consideration for 89% of agriculture's greenhouse
gas mitigation potential (Soil Association 2009). FAO (2009)
reported that overlaying FAO Carbon-Gap and Hunger Maps,
which respectively show (i) soils lacking carbon (“carbongaps”) and (ii) the geographic incidence of hunger, reveals
that countries or regions with large food insecure populations
often also have large “carbon-gaps,” which result in low-yield
production and may increase climate vulnerability. A number
of agricultural management practices, including those
employed in organic and conservation agriculture capture
carbon from the atmosphere and store it in agricultural soils.
These practices involve increasing the organic matter in soils,
of which carbon is a main component. This, in turn, increases
fertility, water retention and the structure of soils, leading to
better yields and greater resilience.
1
Oladele, O. Idowu, Department of Agricultural Economics and
Extension. North West University Mafikeng Campus Mmabatho 2735.
Private Bag X 2046 South Africa.
Tel +27183892746 Fax +27183892748
Email: [email protected], [email protected]
2
Ademola K. Braimoh, Senior Natural Resources Management
Specialist, Agriculture and Rural Development Department (ARD)
The World Bank, 1818 H Street, NW, Washington DC 20433 USA.
Telephone: + 1 202 473 1640
E-mail: [email protected]
Nature & Faune Volume 30, Issue No. 1
75
Soil Science Society of America (SSSA, 2001) recognizes that
C is sequestered in soils in two ways: direct and indirect “Direct
soil C sequestration occurs by inorganic chemical reactions
that convert CO2 into soil inorganic C compounds such as
calcium and magnesium carbonates.” Indirect plant C
sequestration occurs as plants photosynthesize atmospheric
CO2 into plant biomass. Some of this plant biomass is
indirectly sequestered as SOC during decomposition
processes. The amount of C sequestered at a site reflects the
long-term balance between C uptake and release
mechanisms. Because those flux rates are large, changes
such as shifts in land cover and/or land-use practices that
affect pools and fluxes of SOC have large implications for the
C cycle and the earth's climate system. Different ways and
mechanisms to mitigate climate change include either
reducing GHG emissions or by capture or sequestration of C
in aboveground biomass or soils. Soil C sequestration - often
with a focus on agricultural soils - has been repeatedly
proposed as a promising way out of the dilemma (Lal, 2002,
2011). The argument quite often relies on the magnitude of C
stored in soils as well as the vast land area coverage of soils.
Agricultural soils occupy 37% of the earth's surface. The C
found in the upper 1m of soils is estimated to about
2000e2500 Gt, whereas about 60% of this is organic (SOC)
and about 40% inorganic (Sommer and De Pauw, 2011). Thus,
the amount of C in soils is for instance approximately three
times higher than the amount of C bound in the aboveground
biomass, and at least 230 times higher than the 2009-global
anthropogenic CO2 emissions. So, the argument is that small
positive changes in the global SOC pool could have a major
impact, or in other words, soils could be major sinks of the
GHG carbon dioxide. This argument is captured within the
carbon wedge framework of Pacala and Socolow (2004) in
which 'adoption of conservation tillage in all agricultural soils
worldwide', is included as a component of the carbon wedge
'natural sinks'.
Soil is central to most SLM technologies because it is the basic
resource for land use. It supports all the terrestrial ecosystems
that cycle much of the atmospheric and terrestrial carbon. It
also provides the biogeochemical linkage between other
major carbon reservoirs, namely the biosphere, atmosphere,
and hydrosphere. Soil carbon has a strong correlation with soil
quality, defined as the ability of soils to function in natural and
managed ecosystems. Soil carbon influences five major
functions of the soil (Larson and Pierce 1991), namely the
ability to accept, hold, and release nutrients; accept, hold, and
release water both for plants and for surface and groundwater
recharge; promote and sustain root growth; maintain suitable
biotic habitat; and respond to management and resist
degradation. Increasing soil organic carbon can reverse soil
fertility deterioration, the fundamental cause of declining crop
productivity in developing countries.
Sustainable land management provides carbon benefits
through three key processes, namely carbon conservation,
reduced emissions, and carbon sequestration. Many natural
land systems such as native forests, grasslands, and wetlands
have relatively high carbon stocks. Conserving this terrestrial
carbon pool accumulated over millennia should be a major
priority, as it offers the greatest least-cost opportunity for
climate mitigation and ecosystem resilience. Zero tolerance
for soil erosion is indispensable for soil carbon conservation.
Removal of the vegetation cover aggravates losses by soil
erosion and increases the rate of decomposition due to
changes in soil moisture and temperature regimes. Because
soil organic matter is concentrated on the soil surface,
accelerated soil erosion leads to progressive depletion of soil
carbon. Bush (tree) encroachment into savannah and
grassland areas can increase carbon sequestration, but
enhances soil erosion, especially sheet erosion of the fertile
topsoil with the highest SOM levels in the profile. The latter
may outweigh the former (Eldridge, et al 2011).
Methods
A review of the scientific literature on soil carbon
sequestration in Africa was carried out to assess the
greenhouse gas mitigation potential of trees/forest,
afforestation and woody perennials (such as coffee / cocoa
plantations, fruit orchards, and trees) activities using on-line
scholarly and scientific databases as well as more general
search engines such as Google. Due to paucity of such
research in Africa, all possible retrievable publications in
scientific journals and reports were considered. Most of the
review covers carbon sequestration and modeled values or
estimates as published. Estimates of soil carbon sequestration
rates were converted to net climate mitigation benefits
(abatement rates) by converting the C sequestration rates to
carbon dioxide equivalent and adjusting for emissions
associated with the land management technologies (Eagle, et
al 2010). The analysis considered the fact that most studies
reported concentrations of carbon in soil samples (Cc in g kgl). These were converted to volumes and then areas to
'
1
calculate stocks (Cs in kg- ha- ) and sequestration rates (kg
ha-' yr-l) using bulk density (BD, in g crrr-) and sample soil
depth (0, in cm)
Cs = BD x Cc x D x 10,000
In a few studies, value was given in terms of percent soil
organic matter. In these cases, concentrations of Cc (g kg-I)
were calculated as
Cc = 0.58 x OM% x 10
In some cases, only a single value, either initial or average
across treatments, was provided for bulk density. In these
cases, that value was assumed to apply to all treatments. If no
bulk density information was provided in a paper (or other
reports about the same study cited by that paper), then bulk
density was estimated using known pedotransfer functions
(that is, simple regression equations) developed for that
region or extracted from the International Soil Reference
Information Center–derived soil properties database
(www.isric.org).
.
Results and discussion
Table 1 presents the summary of observed rates of soil carbon
sequestration for trees/forest, afforestation and woody
Nature & Faune Volume 30, Issue No. 1
76
perennials covered in this review. From Table 1, the practice of keeping trees on the field and the use of forest based farming
(Taungya system) sequestered an average of 1204 kg C ha-1 yr-1. Agroforestry has the potential to sequester significant amounts
of carbon for 2 reasons. First, the area currently in crops and pastoral systems is large. Second, although the density of carbon
storage is low in comparison with forests, the woody biomass of agroforestry systems could provide a source of local fuel. This
fuel would reduce pressure on the remaining forests in the area and, at the same time, provide a substitute for fossil fuel. These
effects are important because the most effective way to use land for stabilization of atmospheric carbon is through the
combination of reforestation and substitution of wood fuel for fossil fuel (Hall et al. 1991). Takimoto et al (2008) reported that F.
albida parklands, stored more C than improved agroforestry systems (live fence and fodder bank) or abandoned land. Similarly
Garrity (2010) indicated that the carbon sequestration potential of agroforestry systems varies greatly from under 100Mt to over
2000Mt of carbon dioxide equivalent per year particularly the use of Faidherbia albida, in Malawi and Niger. The biophysical and
spatial potential for carbon sequestration in Africa is high but the socio-political conditions related to land usage, ownership and
permitted land management practices are not, constituting a serious dilemma for carbon storage on the continent—and a
similar dilemma for biofuel projects. The prevailing land tenure practices in Africa will influence how afforestation and
reforestation will improve soil carbon sequestration. Kauppi and Sedjo, (2001) recommended the development and
implementation of Western notions of property rights, along with improved governance, local participation, and sustainable
development in order to overcome the limitations of land tenure in afforestation and reforestation land management practices.
Afforestation recorded a mean carbon sequestration of 1163kg C ha-1 yr-1; while for grazing land and cropping intensity had 799
and 896 carbon sequestration kg C ha-1 yr-1 respectively. Lal, (2004) noted that afforestation, the establishment of tree plantations
has a large potential for SOC sequestration in the tropics. Deans et al. (1999) reported that in dry savannahs SOC accumulation
under 18-year plantation of acacia senegal in northern Senegal at the rate of 0.03%/yr under the tree canopy and 0.02%/yr in the
open ground, corresponding to SOC sequestration rates of 420 and 280 kg C/ha/yr for a soil bulk density of 1.4 Mg/m3. Johnson
(1992) reported a > 35% increase in soil C following the afforestation and reforestation of cultivated soils.
In this review, 44 estimates on the use of woody perennials such as cacao plantation in Ghana and Cameroon, coffee plantation
in Burkina Faso, indigenous fruit trees in South Africa, oil palm plantation in Côte d'Ivoire, exotic tree species in Ethiopia, rubber
plantation in Nigeria and Ghana, cashew and teak plantation in Nigeria were covered. The average carbon sequestered from
-1
-1
woody perennials was 2303 kg C ha yr (Table 1). Ofori-Frimpong et al (2010) stated that cacao planted at low plant density and
under shade stores more carbon per unit area of soil than an equivalent area of cacao planted at high density without shade. In
addition to C sequestration in biomass and soil, tropical plantations are needed for timber, and more importantly, as fuel wood for
cooking. In western Nigeria, Ekanade et al. (1991) reported that the SOC pool under forest was 29 g/kg and that under cacao was
19 g/kg. Similar observations were made by Adejuwon and Ekanade (1988) in Oyo state, Nigeria. Also in southern Nigeria,
Ogunkunle and Eghaghara (1992) observed that the SOC concentration under 10-year old cacao plantation was 25 g/kg
compared with 35 g/kg under forest. In Nigeria, Aweto (1987) reported that the SOC concentration was 14 g/kg under primary
forest and 12 g/kg under a 18-year old rubber plantation. The SOC concentration under rubber increased over time. In Kade,
Ghana, Duah- Yentumi et al. (1998) reported that the SOC concentration of a soil under 40-year old rubber plantation was lower
than that under virgin forest or 20-year old cacao. Both rubber and cacao received neither fertilizer nor manure. The high
variability in the minimum and maximum amount of carbon sequestered by trees/forest, afforestation and woody perennials land
management practices could be attributed to the intervening variables and different interaction such as soil conditions,
vegetation cover, temperature, amount of precipitation, soil types among others in the sites where data were collected
Table 1: Summary of observed rates of soil carbon sequestration by trees/forest, afforestation and woody perennials*
Carbon sequestration Kg C ha -1yr -1
Practices
Mean
Lower 95%
CI of mean
Upper 95%
CI of mean
Min
Max
Number of
estimates
Trees/forest
1204
798
1610
273
1732
125
Afforestation
1163
619
1706
97
5880
37
Woody perennials
1359
755
1964
147
9135
44
*The mean score of soil carbon sequestered in afforestation land management practices was used for computation
The carbon sequestered was calculated in terms of tCO2eha-1 yr-1, which can expressed as a climate change mitigation benefit.
Table 2 presents the different values for each of Trees/forest, Afforestation and Woody perennials based on the mean amount of
carbon sequestered. Woody perennials have the highest Climate Change mitigation potential with 4.99 and 7.53 tCO2eha-1 yr-1
respectively. This is followed by the trees/forest 6.69 tCO2eha-1 yr-1. These practices will among other considerations for other
factors be interpreted cautiously as effective for climate change mitigation.
Nature & Faune Volume 30, Issue No. 1
77
Table 2: Climate Change mitigation benefits of trees/forest, afforestation and woody perennials
Practices
Mitigation potential
tCO2eha-1 yr -1
Land
Emissionsa
N20 and CH4
Process
Emissions a
Net Impact
t C02e ha-1
yr -1
t C02e ha-1
yr -1
t C02e ha-1
yr -1
Trees/forest
4.42
0.76
1.51
6.69
Afforestation
4.27
1.41
1.87
7.55
Woody perennials
4.99
0.76
1.78
7.53
a All values in this column are from
(Eagle et al., 2010)
Conclusion
References
This review has revealed that there is high potential to
sequester additional carbon through trees/forest,
afforestation and woody perennials. Most of the review covers
carbon sequestration and modeled values or estimates as
published. Estimates of soil carbon sequestration rates were
converted to net climate mitigation benefits (abatement rates)
by converting the C sequestration rates to carbon dioxide
equivalent and adjusting for emissions associated with the
land management technologies (Eagle, et al 2010). The
analysis considered the fact that most studies reported soil
carbon in different units. In some cases, only a single value,
either initial or average across treatments, was provided for
bulk density. In these cases, that value was assumed to apply
to all treatments. If no bulk density information was provided in
a paper (or other reports about the same study cited by that
paper), then bulk density was estimated using known
pedotransfer functions (that is, simple regression equations)
developed for that region or extracted from the International
Soil Reference Information Center–derived soil properties
database. The most prominent practice is woody perennials
(cocoa, oil palm and rubber plantations). The performance of
these practices depends on soil properties and climatic
conditions, and the degree of soil degradation at the time of
intervention. African countries are unlikely to engage in soil
carbon sequestration unless there are clear local economic
and societal benefits. Therefore, it is essential to estimate all
potential costs and benefits related to the various
management options. Large-scale adoptions of ecologically
sound land use practices are likely to be the most cost
effective and environmentally friendly option to increase soil
carbon sequestration in Africa (Tieszen 2000). There is need
for more awareness of the use of trees, forest, afforestation and
other woody perennials for climate change mitigation other
than the prevalent socio-economic uses.
Adejuwon, J.O., Ekanade, O.1988. A comparison of soil
properties under different land use types in a part of the
Nigerian cocoa belt. Catena 15: 319-331.
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Nature & Faune Volume 30, Issue No. 1
80
Sustaining soil natural capital through
climate-smart farmland management
Ernest L. Molua1, Marian S. delos Angeles2 and Jonas
Mbwangue3
Summary
Sustainable soil management is essential for food security and
agricultural sector growth. Increased degradation and
declining fertility in the advent of increasing climate variability
and climate change is impacting negatively on farm
performance in sub-Saharan Africa. This paper reviews the
economics of soil management in the World Bank's
Sustainable Natural Capital programme pilot sites in
Cameroon and unveils perspectives in developing soil fertility
solutions through sustainable l and management
programmes. While noting that healthy soil is fundamental for
sustained agricultural productivity, a comprehensive
framework is proposed for sustainably managing soil natural
capital under an exogenous driver of climate change. This will
facilitate rolling-out farmland soil techniques that are climatesmart, and simultaneously enhance productivity increases
and soil ecosystem resilience.
1. Introduction
Most countries in Sub-Saharan Africa (SSA) largely depend
upon their natural resources for their basic livelihoods and
economic development. Healthy soil is wealth for agro
ecosystems, being important in crop production through
supporting the fundamental physical, chemical, and
biological processes that must take place in order for plants to
grow; as well as regulating water flow between infiltration,
root-zone storage, deep percolation, and runoff (Dominati et
al 2010; Barrios, 2007). However, two major factors, namely (i)
land-use change associated with population dynamics, and
(ii) global climate change, threaten the longer term
sustainability of the soil natural resource base. Soil is a natural
capital essential for food security, agriculture sector growth
and sustainable land management (FAO, 2001). However, the
increased degradation and declining fertility of SSA soils
contribute to food insecurity and poverty (Dale, 2007; FAO,
2001). The World Bank, FAO and partner agencies have
supported the implementation of national Soil Fertility
Initiative action programmes to tackle the problem. Furthering
this effort, in 2007 the World Bank initiated the Sustaining
Natural Capital (SNC) capacity building program, under the
auspices of the World Bank Institute4. Cameroon was
amongst one of ten target countries in SSA, which also
included Burkina Faso, Burundi, Chad, Ghana, Guinea Bissau,
Kenya, Liberia, Nigeria and Senegal.
The efforts to improve soil fertility management are
challenged by increasing climate variability and climate
change which are already having an impact on agriculture
and food security as a result of increased prevalence of
extreme events and increased unpredictability of weather
patterns (FAO, 2009; Lobell et al 2008). The impact of climate
change on agriculture and agriculture's contribution to
greenhouse gases present an opportunity for renewed
C l i m a t e - S m a r t A g r i c u l t u re ( C S A ) p r a c t i c e s t h a t
simultaneously promote adaptation and mitigation. CSA, as
defined and presented by FAO at the Hague Conference on
Agriculture, Food Security and Climate Change in 2010,
contributes to the achievement of sustainable development
goals. However, missing from recent studies in CSA and SNC
with respect to soil fertility management is adequate
recognition of the role of economics in soil productivity at
farm, national and global levels (Turner and Daily, 2008; Ekins
et al 2003). This paper attempts to address this shortfall by
reviewing the returns to soil fertility management as precursor
for CSA.
2. Materials and methods
Data is drawn from research survey with participants in the
World Bank's SNC pilot sites, in the West and Northern regions
of Cameroon. Two hundred and fifteen farms were studied in
six communities within these three regions: North region
(Fada, Gamba and Mayo Lebri), Adamawa region (Njoundé)
and West region (Lagui and Kouptamo). These regions
experience different variations of climatic regimes, particularly
the effect of differing topography on their microclimates. The
sahelian North region where rainfall averages 500–1000 mm
per year is drier than the Adamawa region (900 to 1,500 mm
per year) and the West region (1,000 to 2,000 mm per year)
Specific assessments were undertaken to identify suitable
agricultural production technologies and practices which
address the complex interrelated challenges of food security,
development and climate change, and identify integrated
options that create synergies and benefits as well as identify
barriers to adoption, especially among farmers, and
recommend a framework for policies, strategies, actions and
incentives.
1
Ernest L. Molua, Department of Agricultural Economics and
Agribusiness, Faculty of Agriculture & Veterinary Medicine,
University of Buea, Cameroon,
P. O. Box 63 Buea, Cameroon.
Tel: (+237) 699 49 43 93; Fax: (+237) 243 32 22 72;
E-mail: [email protected]
ALSO: Centre for Independent Development Research;
P. O. Box 58 Buea, Southwest Region, Cameroon
Tel: +237 243 008 782; Fax: +237 243 323 014,
Email: [email protected]
2
Marianne S. delos Angeles.
Resources, Environment and Economics Center for Studies, Inc. ,
Quezon City, Philippines. 41 Dodge St, Filinvest Homes 2 Batasan Hills,
Quezon City, Philippines 1226
Telephone: +63 2 931 5468.
Email: [email protected]/[email protected]
3
Jonas Mbwangue, Sabin Vaccine Institute, 2000 Pennsylvania Avenue,
Suite 7100 Washington, DC . 20006 United States of America
Email: [email protected]
4
For more information about the SNC program, visit:
http://www.worldbank.org/wbi/environment/snc
Nature & Faune Volume 30, Issue No. 1
81
3. Results and discussion
Most of the small-scale producers studied were already
coping with degraded nutrient poor soils. They report having
limited assets and risk-taking capacity to access and use
modern technologies and financial services. Adoption of soil
management options to manage moisture-related stress
were reported by 16.7%, 31.7% and 12.3% of farm households
in the North, Adamawa and West regions, respectively,. Other
measures include various indigenous crop management
measures and socio-cultural practices, such as planting in
mixed and/or intercropping systems, as part of a scheme of
crop rotation or in agroforestry systems. Soil nitrogen and
other nutrients are recognized as essential to increase yields.
Farmers rely on composting manure and crop residues, or
using legumes for natural nitrogen fixation. There are,
however, conspicuous differences between the choices in
drier northern Cameroon relative to the humid western part of
the country. The agroecologically less favoured communities
in the sahelian North region use a variety of risk minimization
strategies based more on biological sources of nutrients,
resilient crop varieties or species, and integrated land and
water management. In the North region, methods and
practices that increase organic nutrient inputs (e.g. compost
and manure) are fundamental and compliment farmers'
investment in synthetic fertilizers which, due to cost and
access, are rarely available to them. Farmers in the West
region put more emphasis on inorganic soil fertility
management with the possibility of shifting to new farmland
sites as soil fertility declines. In some farm plots in the
Adamawa region, nutrient stocks and flows of soil fertility are
managed through a range of other strategies that promote
nutrient recapitalization by combining organic and inorganic
nutrient sources, e.g. applying inorganic fertilizers, using
organic manures and legumes to fix atmospheric nitrogen.
This is reinforced, in the humid West region, with production
practices that emphasize soil productivity through integrated
nutrient and water management, e.g. no-till production,
conservation tillage, or mixed cropping that combines food
crops with cover crop legumes and/or tree and shrub species.
Specifically, managing soil physical and biochemical
properties include a range of farm-level private autonomous
measures such as stone terracing, soil bunds and
construction of live fences. In all the three regions, traditional
slash and burn farmland preparation by low-income farmers
and the application of organic and inorganic fertilizers are
significant activities in their soil management repertoire.
The farmers were found to have considerable knowledge of
the rainfed ecosystems they operate, making informed
decisions based on experience regarding the choice of
cropping patterns and various management options.
However, the cultivars grown are often not adapted to the
climatic conditions since they are not indigenous but cultivars
developed for the enhancement of other traits rather than
their climatic relevance. Hence, while there is considerable
traditional knowledge of rainfall and temperature variability,
farmers are still sceptical about the short- and medium-term
benefits of the new crops/cultivars that are introduced. More
than 60% perceive changes in local climate. To cope with
climate change, specific management practices are taken
into account: the types of crop, grazing and forest systems, the
diversity and current status of soils (e.g. sand/loam/clay soils,
peat soils, sodic soils, shallow soils, nutrient depleted soils,
etc), terrain (e.g. steep/flat lands, wetlands) and climatic
conditions (e.g. short rainy seasons, erratic rains, high
temperatures, storms). Farmers expressed a need for a climate
information portfolio to enhance their productivity with the
following information: date of onset of rainy season, quality of
rainy season (rainfall amount), date of end of rainy season,
frequency and timing of adverse weather events e.g.
floods/dry spells within the season, temporal and spatial
distribution of rainfall, interpretation of weather forecasts in
terms of which crops and varieties to plant and when to plant.
Hansen et al (2008) reiterate the feasibility of such climate
forecasts improving farm outputs.
Farmers were then grouped and evaluated on their average
ex-post economic returns to climate-smart soil management
practices. In the North region, the average farm income for
SNC practicing farmers is estimated at 215,000 FCFA (US$
430) per hectare, in the Adamawa region it averaged 167,000
FCFA per (US$ 334) hectare and 124,000 FCFA (US$248) per
hectare in the West region. The return-on-investment (ROI)
computed as percentage ratio of farm profit to soil
enhancement costs was 137%, 122% and 115% for farmers in
North, Adamawa and West regions, respectively. This
indicated that the farmers were likely to realise 37%, 22% and
15% above the capital invested in soil management. The
internal rate of return (IRR) which captures the marginal
efficiency of investment for such farmland investments were
17% minimum and 28% maximum for the North region, 14%
minimum and 23% maximum for the Adamawa region and
11% minimum and 19% maximum for the West region. The
Benefit Cost Ratios (BCRs) at 10% discount rate were 3.8, 2.5
and 1.6 for farmers in the North, Adamawa and West regions,
respectively. Consistently, private farmland investments with
respect to SNC recommended organic soil productivity
improvements observe higher returns in the drier regions of
the country relative to regions with increasing investments in
inorganic soil enhancements. Though location specificity
may be driving these differences, the general conclusion may
be that of overall attractiveness of adopting low cost
improved soil management measures in climatic risky
locations. However, rolling-out such effort will require
proactive and effective government support at the
production and distribution stages of agricultural production.
In a forum for the Cameroon Parliamentarians' sub-group on
environment to raise awareness on issues related to SNC and
Climate Change Adaptation, it was unanimous that farmers'
capacity to make the required adjustments depends on the
existence of policies and investments to support their access
to credit, insurance, as well as on proper economic incentives.
Policy is important to shape the incentives and enabling
environment to expand the opportunities available to such
farmers. For example, inputs of information and technical
expertise can facilitate changes in farm practices which
Nature & Faune Volume 30, Issue No. 1
82
improve the management of soil resources. The law-makers were unanimous tat the profitability of farm enterprises could
motivate farm decisions, sustainable natural resource management and generate feedback effects on the natural and human
resource attributes. If the sustainable resource management practices are not profitable the impacts may be to reject them,
leading to degradation of natural capital, expressed as declining soil quality (Dale, 2007). On the other hand, if they are profitable,
it will give positive feedback about sustainable natural resource management that reinforces households' resource base and
improve on their perception of the plausibility of regarding them as acceptable farm practices. Policies that create enabling
incentives are therefore primordial in shaping farmers' decisions. However, the survey reveals that the adoption of CSA options is
also constrained by a lack of tenure security, which may affect farmers' incentives to adopt because of the time delay in enjoying
the benefits from CSA and farmers' limited access to finance and insurance.
Figure1 below highlights a comprehensive framework for sustainably managing soil natural capital under the exogenous driver
of climate change. The framework consists of five main interconnected components: (a) soil natural capital, characterised by
standard soil properties; (b) exogenous drivers of soil change; (c) direct and indirect benefits from soil e.g. provisioning,
regulating and cultural ecosystem services; (d) private farmland management choices and (e) policy linkages to enhance soil
ecosystem services. It is a holistic approach linking soil ecosystem services (Daily et al 1997) to soil natural capital (Costanza and
Daly, 1992). Through policy linkages, the promotion of research, technology development and extension, farmers could be
provided with more tools to manage soil properly and enhance its ecosystem services - beneficial flows arising from natural
capital stocks (Porter et al 2009; Swinton et al 2007). Policy-makers may borrow from a set of tools or instruments, such as rural
credit programmes, input and output pricing policies, including input subsidies, property rights, extension services as well as the
implementation of safety net programmes, they can apply to change the incentives and enhance capacity of farmers in their
private investments on sustainable soil management. The policy environment would have to provide for market access (for
inputs and outputs), competitive input costs and attractive producer prices to incentivise adaptation and adoption of soil
productivity management measures.
Land use change
Soil Natural Capital
(Soil quality)
Direct Benefits
(provisioning services,
cultural services)
Indirect Benefits
(regulating services)
Policy Linkages &
M arket Incentives
Farmland Soil management
Climate change
Figure 1: Framework for sustainable management of soil natural capital
Source: authors' conceptualisation
4.Recommendations and conclusion
Enhancing agricultural performance requires agricultural
production systems to be productive in the face of climate risk.
The World Bank SNC program highlights evidence of the
benefits of sustainable land management choices that are
climate-smart, in terms of productivity increases and
resilience. To achieve agricultural development goals,
adaptation to climate risk must be accomplished without
depletion of the natural resource base, especially the soil
resource. Management practices that increase soil organic
carbon content from year to year through organic matter
management will bring win-win benefits. In the pilot survey in
Cameroon, good soil productive management was shown to
contribute to farm income for climate change perceiving
farmers. However, there is still need for in-depth study of the
market, policy and institutional factors that would shape and
structure farmer incentives and investment decisions in
rolling-out SNC approaches in CSA enterprises.
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Nature & Faune Volume 30, Issue No. 1
84
Agricultural intensification by small-scale
farmers in hydromorphic wetlands as a tool to
counteract climate change effects: a case
study in Xai -Xai district in Mozambique
Paulo Chaguala1 and Laurinda Nobela2
Summary
Climate Change phenomena is a threat for rural communities
living basically with agriculture particularly smallholder
farmers lacking financial means and knowledge on good soil
management practices of lowlands. The availability of water in
lowlands and easy way of irrigation through capillary
ascension with a well defined dry period make it possible to
have two or more growing seasons a year, rice crop in rain
season and other crops in dry season. The study was carried
out in Xai -Xai district located in southern part of Gaza province,
Mozambique in a semi-arid area threatened by changing in
climate, is crossed by Limpopo river, the major soil types are
arenosoils in the upper land and hydromorphic soil in low land.
Smallholder farmers in the surrounding communities were
used to grow their crops in the upper lands avoiding low lands
before experiencing continuous crop failure as a result of
climate change due to the type of predominant native
vegetation associated with poor soil drainage what make land
preparation difficult. The lack of knowledge on management
of hydromorphic soils by the smallholder farmers was another
reason of not exploring this land. The study objective was to
understand how crop production should be intensified under
this ecosystem and promote better soil, water and crop
management practices. Crops like rice, in rain season and
maize, onion, common beans and cabbage in dry season were
cultivated. By doing so, farmers were able to produce self
sufficient food and raising family income all over the year,
meanwhile their skills on use and management of these type of
soils were improved. Crop yield of maize in the lowland is more
than three times high (1500 to 3000 kg/ha) compared to upper
land (200 to 800kg/ha). The intensification reduced food
insecurity in the community and creates a source of income.
Farmer's ability to use soil resources in hydromorphic in a
sustainable way was improved.
Introduction
Xai Xai district in Mozambique has a large area of
hydromorphic soils in seasonally flooded wetlands locally
known as machongos, with medium to high potential for crop
production (rice, beans, maize, potatoes and vegetables)
along the Limpopo river. Such wetlands cover large areas also
in other parts of Africa, where they are known as vleis (South
Africa and Zimbabwe), dambos (Zambia), Mbugas (East
Africa) and fadamas (West Africa) (Daka, 2001). The annual
average rainfall in Xai Xai district is 1135.9 mm and with an
average temperature of 22.3°C (Kassan and Velthuizen,
1981). The nature of the soil types and predominant native
vegetation associated with poor soil drainage make land
preparation difficult. Thus most farmers were cultivating only
small areas to grow sweet potatoes and vegetables for home
consumption during the dry (non-flood) season. However, the
constant crop failure experienced in the uplands due to
climatic variations changed the farmers' attitude. They started
to invest more effort in the use of the low lands. They asked for
help from extension services and researchers regarding
improved utilization and management of these soils. It was in
this context that demonstration experiments with rice, maize
and cabbage were conducted at the Poiombo Farmers
Association community in Xai-Xai district (24° 55' 47.5'' S; 33°
42' 33.3'' E). The main objective of the experiments was to
demonstrate integrated soil fertility management (ISFM )
practices in managing and cropping in seasonally flooded
hydromophic soils. A specific objective was to develop a
nitrogen fertilization and management package for rice
production in that specific type of environment.
Material and methods
Site description
The land was permanently wet and agricultural use in these
soils was impossible before a drainage system was installed
After the establishment of drainage channels it was possible
to regulate water depth. Hence limitations due to salinity,
sodicity or acidity were minimized, making thess soils
workable for agricultural practice all year round. The soil is a
typical peat soil, formed by accumulation of organic materials,
with a water table fluctuating between the surface and 40 cm
as controlled by channel systems. Crop irrigation is basically
through capillary rise of water from a water table.
1
Paulo Chaguala.
IIAM-DARN, Directorate for agriculture and natural resources,
Soil fertility Division, Av. das FPLM Nr.2698
P. O. Box 3658, Maputo, Mozambique.
Email: [email protected]
2
Laurinda Nobela.
Eng3 Agrónoma, MSc. (Agric) Soil Science, Agricultural Research
Institute of Mozambique (IIAM) Soil Fertility Researcher, Av. FPLM 2698,
P. O. Box 3658, Maputo, Mozambique.
E-mail:[email protected]
Tel.: (258) 82 7823 640 /84 7062 570
3
Centimol (cmol) (+)/kg.
Centimol (cmol) is a standard unit for
expressing the concentration of cations in a comparable way
Nature & Faune Volume 30, Issue No. 1
85
Table 1. Properties of the soil at the experimental site
3
Extractable bases (cmol +/kg )
(Ammonium acetate)
Soil
depth
(cm)
pH
pH
H2O
KCl
EC 1:2.5 H
mS/cm cmol+
/kg
Al
cmol+
/kg
Total N % Avail P
(Kjeldhal) mg/kg
OM %
(BrayI)
(loss
ignition)
Ca
Mg
K
Na
0-20
4.3
3.7
2.16
0.9
1.15
0.84
25.1
29.6
2.19
4.94
0.72
1.76
20-40
5.2
4.1
0.75
1.2
0
0.03
31.1
26.6
2.41
4.34
0.84
1.62
The soil is strongly acidic, with pH (Water) ranging from 4,3 to
5,2 (Table 1). The electrical conductivity (EC) varied from 0,75
to 2,16 mS/cm and thus only sensitive crops would be
affected negatively by salinity, Total nitrogen is high in the top
soil, but low in the subsoil. The soil's phosphorus content is
optimal, varying from 25,1 to 31,1 mg/kg (Bray 1). Soil organic
matter was very high (more than 25%) as is normal when
dealing with peaty soils. The Ca/Mg ratios are very low (0.44
and 0.55) not favorable for calcium nutrition. At these ratios
Mg will also cause dispersion of soil colloids, thus
destabilising soil structure. The Mg/K ratios are high (6,86 and
5.17) as are the (Ca+Mg)/K ratios (9.90 and 8.04). These are,
however, still acceptable for potassium absorption.
Methodology
2013, after starting of the rain season. The planting density
was 166 667 plants/ha.
Experiment on conservation agriculture: soil nutrient
use efficiency for maize intercropped with leguminous
crops, under till and no-till systems
The first objective was to demonstrate the advantage of the
use of total herbicide (glyphosate, commonly called
roundup) in land preparation compared with conventional
tillage; and evaluate the contribution of a conservation
agriculture system to soil nutrient availability and crop yield.
The second objective was crop diversification with maize as a
staple food and beans as diet improvement and for income
generation.
The trial was planted in the cool and dry season of 2013 and
the experimental layout was a split plot design with land
preparation (tilled and no tilled) as main plot and fertilizer
application as sub-plot (3 levels of nitrogen 0, 40 and 80 kg
N/ha) with a basic phosphorus application of 18 kg P /ha; with
three replications. Matuba variety was used for maize and
PAN 148 for phaseolus vulgaris; maize was planted at spacing
of 80cm x 40cm and the beans were planted intra maize rows.
The fertilizer application was localized per hole where N
fertilizer was only applied for maize while P fertilizer was for
both crops. The second phase of the experiment was planted
in the cool dry season of 2014. The highest level of N fertilizer
(80 kg/ha) was omitted as no significant difference was
observed between it and the lower level of N (40kg/ha) during
the first season.
For the rice experiment the experimental design was a split
plot with three levels of nitrogen (0, 80 and 100 kg ha-1) as
main plot and four rice cultivars (Makassane, M'ziva, IR 64 and
Limpopo) as sub-plot, using three replicates. The 80 kg N/ha
application rate was calculated based on soil analyses and
crop requirement (Frank Bernard method). The 100 kg N/ha
application rate was extracted from the general fertilizer
recommendation of annual crops of Mozambique
0
(Comunicação N 88, INIA). To ensure phosphorus won't be a
limiting factor for nitrogen absorption and to ensure soil P
maintenance 6.2 kg/ha P were applied in all treatments except
in the control simulating farmers' practice. According to
research results the potential productivity of the selected
cultivars are 7-7.8 t/ha for Makassane, 3.5-4 t/ha for M'ziva and
5-6 t/ha for both Limpopo and IR64. All four selected cultivars
are long season cultivars, with growing periods ranging from
120 days for IR64 and Limpopo to 128 days for M'ziva and 130
days for Makassane.
Effects of mineral fertilizers on cabbage yield in the
Machongos
Due to the grassland nature of natural vegetation
predominant in this type of ecosystem for land clearing a nonselective herbicide was sprayed instead of the traditional way
of burning. It was to demonstrate to the community that
burning is not a good practice to clear an organic soil, since it
can cause drastic harm to the soil and environment. The
experiment was planted during the last week of November
The objective was to evaluate the effect of minimum
application rates of nitrogen on cabbage yields in this type of
soil. An on- farm experiment was established the during cool
dry season after the rains in a split plot design with 2 levels of
land preparation (till and no-till) as main plot and fertilizer
application as sub-plot with 4 levels of nitrogen (0, 20, 40 and
80kg N/ha) with 3 replicates. The variety Gloria F1 was
Nature & Faune Volume 30, Issue No. 1
86
cabbage. The experiment was planted at the spacing of 60cm x 40 cm and the fertilizer application was localized by row.
Obtained yield results were statistically analyzed using Statistx 9 package.
Results and discussion
Rice experiment
Where no fertilizer was applied the average yield of all cultivars ranged between 1.8 to 2.2 ton/ha and there were no statistically
significant differences (Figure 1). The cultivars reacted significantly different to application of different levels of nitrogen. IR64
and Limpopo showed very high yield increases in response to N application. Their responses were of the same order and not
statistically different. Both these cultivars reached their genetically potential yields of 5-6 t/ha at the two highest N application
rates. Makassane and Mziva showed relatively poor responses compared the other two cultivars to N fertilization, giving
statistically significantly poorer response. At the highest N application rate the yield of Mziva did nearly double and it reached its
genetic potential of 3.5 to 4 t/ha. Makassane was the big disappointment, reaching a yield of less than 3 t/ha, while having a
genetic potential of 7-7.8 t/ha. It is possibly not adapted to strongly acid soil conditions, such as prevailed at the experimental site.
It shows the importance of selecting adapted cultivars for specific conditions. The application rate of 80 kg/ha administrated
based on Frank Bernard calculations revealed to be agronomically efficient since the increase to 100kg N/hayield increase was
low and not statistically significant.
Figure 1. Average rice grain yields
Results for the conservation agriculture experiment with maize
For all treatment combinations maize yield was superior under the no-till system in the first year of the trial (2013), but the yields
were extremely low (Figure 2). The beneficial effect of no-till could be explained by the rapid evaporation on tilled plots
associated to low level of water in the channels and it took too long to raise the soil moisture by capillarity. Under no-till yield was
approximately doubled compared to control (means maize sole crop without fertilizer) for all fertilized plots while in the intercrop
without fertilizer the yield increase was 205 kg/ha (about 50%). thus, intercropping maize with beans had a positive effect. In the
tilled plots fertilizers had very little effect, while intercropping with beans had a small negative effect. The latter was probably due
to the higher water demand by the larger number of plants (maize + beans) in these water stressed plots.
In the second season of the trial (2014) the trends changed drastically (Figure 3).Maize yields were still low, but much higher than
during the previous season. Under no-till N fertilizer alone and beans without fertilizer gave about equal yield increases, with the
combination of beans and fertilizer being slightly inferior to these. Under till the N fertilizer alone performed poorly. The big
difference compared with the previous season was that the tilled plots with beans alone outyielded the no-till plots and
especially that the tilled plots having both beans and N fertilizer far outyielded all other treatments. The main reason for the
differences between the seasons was that, unlike in the previous rainy season the rains were good during this season and thus
the channels maintained high water levels. the average maize yield for the control treatment (no fertilizer application or beans)
was 823 and 971 kg/ha for no-till and tilled respectively, and for intercropped plus fertilized plots 1122 and 1686 kg/ha for no-till
and till systems respectively.
Nature & Faune Volume 30, Issue No. 1
87
Figure 2. Maize grain yield 2013
Figure3. Maize grain yield 2014)
Results for the conservation agriculture and nitrogen experiment with cabbage
Figure 4 represents cabbage response to N-fertilizer under till and no-till systems. In the tilled plots yields increased sharply above
the control at the lowest N application rate (20 kg N/ha) and then levelled off. In the no-till plots the yield was significantly lower
than in the tilled plots at the lowest N level, but then rose sharply with each further increase in N application. Consequently at 40
kg N/ha there was no difference between the tilled and no-till plots, while at an application of 80 kg N/ha the yields in the no-till
plots were significantly higher than in the tilled plots. So, for poor small-scale farmers a combination of till and low N application
(20 kg N/ha) would by far be the most feasible combination.
Nature & Faune Volume 30, Issue No. 1
88
Figure4: Cabbage response to N-fertilizer
Conclusion and recommendations
References
Agricultural intensification in hydromorfic soils can help in
building or strengthening rural communities' ability and skills
to overcome climate variability and climate change threats by
providing food all year round and improving family diet, as
well as creating a source of income through cultivation of
vegetable crops. It is highly recommended to grow maize and
vegetables during the dry season after growing rice during the
rainy season.
Beernaert, F., 1991. Manual de avaliação de terra. Nota Interna
DTA/INIA
Using leguminous crops intercropped with maize and the use
of minimum application rates of N results in a positive and
relatively cheap contribution to crop production for smallscale farmers. Increased crop production will require a reliable
market to sell the surplus. This calls the attention for the need
to develop community storage and agro-processing
methods.
Daka, A.E. 2001. Development of a technological package for
sustainable use of dambos by small-scale farmers. PhD.
Thesis, Univ. Pretoria, Pretoria, South Africa. 225 pages. Also
available free on the internet at www.up.ac.za
Gertus, P. , 1997. Recomendações de Adubação Azotada e
fosfórica de culturas anuais alimentares e algodao em
Moçambique. Comunicação N0 88, Serie Terra e Agua, INIA
Kassan, A.H. and Van Velthuizen, H.T., 1981. Climatic
databank and length of growing period Land Resources
Consultants FAO/Moz 75
For reliable conclusions and development of appropriate
p ro d u c t i o n p a c k a g e s a n e c o n o m i c a n a l y s e s i s
recommended.
Nature & Faune Volume 30, Issue No. 1
89
Soil fertility and climate benefits of
conservation agriculture adoption in the
highlands of Tanzania
Janie Rioux1 and Marta Gomez San Juan2
Summary
The restoration and maintenance of soil fertility is essential for
agricultural productivity and food security in rainfed low input
agriculture. Conservation Agriculture (CA) is one set of
practices that can reduce soil erosion and restore soil fertility,
thus improving yield, and contributing to climate change
adaptation and mitigation. This paper presents the effects of
CA on maize yield and greenhouse gas (GHG) fluxes in the
highlands of Tanzania. The results showed that some CA
practices (reduced tillage plus mulch and soil nitrogen
remediation with leguminous trees or N fertilizer) have the
potential to substantially increase maize yields without
increasing GHG emissions, giving more favourable ratios
yield: GHG emission. A high number of farmers reported the
adoption of individual CA practices, ranging from 83% for
minimum tillage to 86% for mulching. However, when looking
at the management of their three main plots, the rate of
adoption of the promoted CA package (reduced tillage plus
mulch and intercropping) was low: 45% for one practice and
only 6% for practicing two CA sub-practices at a time, and no
one practiced the full package of three CA practices. This
shows that whereas scientists set complete packages, farmers
choose and try the individual components of a package. The
main factors determining adoption were wealth and food
security status, land tenure, land availability, labour, perceived
payoffs and access to information and training. The paper
concludes that increasing yield can be achieved in synergy
with reducing GHG emissions, but that the barriers to adoption
need to be addressed. Moreover, incentive mechanisms
should also be put in place to promote the adoption and upscaling of sustainable soil management practices like
conservation agriculture.
Introduction
Conservation agriculture (CA) practices are widely promoted
as part of sustainable soil management and climate-smart
agriculture in Sub-Saharan Africa. The benefits of these
practices on yield are caused by improved soil structure as
well as increased soil fertility, carbon content, and water
retention (Baker et al., 2007; Palm et al., 2014; Powlson et al.,
2014). However, the effects of CA on greenhouse gas (GHG)
emissions are uncertain in most African farming systems.
Moreover, the barriers to the implementation of CA practices
are complex due to their site-specific characteristics.
Therefore, the objective of the study was to test the impacts of
conservation agriculture on yield and GHG emissions, and
analyse the adoption rate and barriers of different CA
practices.
Methods
From 2011 to 2014, the FAO Mitigation of Climate Change in
Agriculture (MICCA) Programme implemented climate-smart
agriculture (CSA) in two pilot projects in Kenya and Tanzania.
The MICCA Pilot Projects promoted the development of a
selection of CSA practices for smallholder farmers based on
expert and participatory assessments. In the Uluguru
Mountains of Tanzania, the menu included conservation
agriculture (CA) practices, agroforestry, soil and water
conservation, and energy-saving cooking stoves to improve
yield and livelihoods as well as to reduce erosion, burning, and
deforestation. Alongside implementation, the selected
practices were evaluated in terms of their food production,
adaptation and mitigation benefits. Moreover the adoption
determinants were analysed to inform CSA up-scaling and
future extension programmes.
The total area under analysis was 16 812 ha and included 18
326 people. The annual temperature ranges between 22 and
-1
33 °C and the rainfall between 1 500 and 1 800 mm yr , with
the long rain period from March to June and the short rains
from late October to early December. The data were gathered
over twenty-one months, from October 2012 to June 2014,
along four growing seasons and two fallow seasons.
Firstly, a study was conducted to assess the maize yield and
GHG emissions from different sub-practices of CA in a 630 m2
experimental plot in the village of Kolero. The experiment
consisted of the rainfed cultivation of fifteen plots: three
replicates of five different treatments, two that were practiced
in the area (1 and 2) and three that were promoted by MICCA
extension activities (3, 4 and 5): 1) conventional cultivation
with hand hoe tillage and random planting; 2) reduced tillage
plus mulch in-between rows; 3) reduced tillage plus mulch
and Lablab leguminous cover crop; 4) reduced tillage plus
mulch intercropped with leguminous Gliricidia sepium trees;
and 5) reduced tillage plus mulch and mineral fertilizer (75 kg
of N/ha). Reduced tillage plots were prepared by first double
digging the soil before the rainy season of 2012, as a first step
in order to prepare the land for the further adoption of reduced
tillage. They were stick planted with maize Tan250 and the
cover crop was sown ten days prior to the planting of the
maize. Also, G. sepium trees were planted seven months
earlier and their foliage biomass was added to the soil after
pruning (2 to 3 times per growing season).
1
Janie Rioux, Natural Resource Climate Change Officer, Organization:
Food and Agriculture Organization of the United Nations (FAO), Climate,
Energy and Tenure Division (NRC), Viale Terme di Caracalla, 00153
Rome, Italy.
Email: [email protected]
Tel: +390657055282
2
Marta Gomez San Juan, Agriculture and Climate Change Consultant.
Organization: Food and Agriculture Organization of the United Nations
(FAO), Climate, Energy and Tenure Division (NRC), Viale Terme di
Caracalla, 00153 Rome, Italy.
Email: [email protected]
Tel: +39 06 570 53839
3
www.fao.org/climatechange/micca/pilots/en/
Nature & Faune Volume 30, Issue No. 1
90
Ÿ
Ÿ
confidence level and 7% confidence interval. The sample was
proportionate among locations, as the main strata for
sampling, and ultimately balanced by gender. Data was
analyzed with the Statistical Package for Social Scientists
(SPSS 20) software.
Maize yield was determined by the estimation of dry
weight per plot, based on the ratio of dry-to-fresh
weights (dried in an oven at 70°C). Both, the final maize
-1
grain and stover yields were expressed in Mg ha . For
the G. sepium intercropping, the N input from the
green manure of foliage biomass left on the soil was
measured at each pruning time. The test consisted of
oven drying and nutrient analysis, and the total N was
calculated as a function of dry matter mass and N
concentration.
Households were the unit of sampling for the questionnaires.
Data were collected on household and farm characteristics,
participation in MICCA project activities, CSA practices
(adoption rate, constraints and incentives), and benefits on
food security and livelihoods. The sampling had already taken
into consideration the participation in trainings and rated the
number of farmers who received trainings to those who
participated in initial awareness raising.
GHG flux measurements were carried out with static
chamber techniques. Chambers were 27 x 37.2 x 10
cm and were placed one week prior to the first
measurement and kept in-situ over the whole season.
Each sampling plot had two chambers, one within a
row between two plants of maize and one between
two rows. During the samplings, the chambers were
sealed for 30 minutes and every 10 minutes the gas on
the headspace was removed using a 60 mL syringe.
ICRAF analysed the sample content with gas
chromatography and converted them on a mass per
volume basis. The SAS system was used to analyse the
normality of the yield and GHG data, at a 5% level of
significance.
Results
Results from the field experiment
The yields, GHG emissions and GHG emissions per yield unit
for different sub-practices of the CA package and
conventional tillage are presented in Table 1.
Kimaro et al. (2015) reported that increases in maize yield were
statistically significant with the treatments including G.
sepium, and fertilizer. Significant differences (p<0.05) in maize
yield were found between conventional cultivation and
cultivation using the treatments of the G. sepium and fertilizer,
for three of the four seasons analysed. No significant
differences were found between G.sepium and fertilizer
practices and between the ones including lab lab and
mulching.
Secondly, structured household interviews (sample size
n=169 with 51% women) were conducted alongside focus
group discussions (n=5) of 6-10 participants each. This was
needed to gather quantitative and qualitative information on
the determinants and outcomes of CSA adoption in 8 villages
in the Uluguru Mountains where the MICCA pilot project was
implemented. A proportionate random sampling was used to
select respondents from the different villages, among the
project participants.
However, regarding the annual emissions, the differences
were insignificant across treatments (p>0.05). When looking
at the GHG emissions intensity (GHGi), i.e. GHG emissions per
-1
unit of yield in Mg CO2eq Mg maize , the G. sepium and
fertilizer practices show more potential, in addition to the fact
that they are the two practices that produce a greater yield
increase of 54% and 43%, respectively.
The random sample of the project participants was computed
as the ratio of the number of farmers who received trainings to
those who participated in initial awareness raising with a 95%
Table 1. Effects of different practices on annual maize yield and annual GHG emissions and GHG emissions intensity
4.5 (22%*)
Reduced
tillage plus
mulch and
Lablab
4.6 (24%*)
Reduced
tillage plus
mulch and G.
sepium
5.7 (54%*)
Reduced
tillage plus
mulch and N
fertilizer
5.3 (43%*)
4.6
5
5.1
5
4.7
1.2
1.1
1.1
0.8
0.8
Conventional
tillage and random
planting
Reduced
tillage plus
mulch
Maize yield (Mg ha-1)
3.7
Soil GHG emissions (Mg
CO2e ha-1)
GHGi (Mg CO 2e grain Mg-1)
Parameters (yearly-basis)
(Source: Kimaro et al., 2015)
* = Percentage increase above the yield with conventional tillage
Results of the farmer survey
The promoted package of CA included minimum tillage, mulching and cover crops/intercropping. A high number of farmers
reported practising single conservation agriculture practices, as can be seen in the Figure 1 below. However, for their three main
Nature & Faune Volume 30, Issue No. 1
91
plots (i.e. bigger size and from which they obtain the majority of their production), the adoption rate was lower, and even more for
combined conservation agriculture practices. Indeed, when looking at the management of their three main plots, the rate of
adoption of the promoted CA package was low: 45% for one practice and only 6% for practicing two CA sub-practices at a time.
No farmer practised the full package of 3 CA sub-practices.
Figure 1: Percentage of farmers practicing individual conservation agriculture sub-practices (FAO, unpublished data)
Main adoption determinants reported by farmers surveyed in the study were wealth and food security status, land tenure, land
availability, labour, perceived payoffs and access to information and training, many of them also mentioned during focus group
discussions. For example, wealthier households were practicing crop rotation because they own more land, and mulching for
growing vegetables, which requires inputs, tools and access to markets. On the other hand, farmers who rent land also adopt
mulching, as this is a temporary, cheap and easy to try practice and it also helps to fight soil erosion on slopes. Insecure land
tenure was mentioned as a barrier to the adoption of conservation agriculture.
Land availability was another commonly cited barrier, as farmers having limited access to land find it risky to test new practices.
Labour (availability and/or cost) was also a constraint for testing and implementing new practices. The perception of high
productivity payoffs in terms of increased yield is a key factor in the adoption of mulching and cover crop (Table 2). In FGDs,
farmers see the potential for improving productivity, especially on the hillslopes. The absence of proper access to information
was also a barrier in the adoption of CA practices. The establishment and promotion of Farmer Field Schools was a successful
factor in adoption (Figure 2). Micro-credit groups can also help farmers, especially women and youth, to adopt new practices.
Table 2. Barriers and incentives in the adoption of CA practices in the Kolero area
Barriers and Incentives
Mulching
Perceived as having the lowest productivity payoff of all CA practices, but as being one of
the two most affordable practices. The main reasons for adoption and continued use given
by around a third of farmers was the promotion by change agents, and the immediate
benefits from adoption. Specific training increases adoption.
Cover
crop/
intercropping
Perceived as being one of the two most affordable CA practices. The main reason for
adoption and continued use given by about 40% of interviewees is the promotion by change
agents. Around a quarter of interviewees also recognized immediate benefits from the
adoption of cover crops. Very few people disadopted cover crops.
Minimum
tillage
Perceived as having the highest productivity payoff of all CA practices. Specific training and
participation in Farmer Field Schools and demonstrations increase adoption. Main reason for
adoption is promotion by change agents. The main reasons for disadoption among the few
that did so were their perception of low pay-offs and better alternative practices available.
Nature & Faune Volume 30, Issue No. 1
92
Figure 2: Farmers practicing conservation agriculture (no tillage, mulching, cover crops/ intercropping)
Discussion and conclusions
The results from the MICCA Pilot Project showed that no
conflicts exist between increased maize production and
reduced GHG emissions through CA in this area of Tanzania.
CA has several advantages for soils and crops that makes it a
promising solution for sustainable soil management.
However, the package of CA practices has multiple barriers to
adoption. Farmers in Kolero tend not to adopt the full bundle
of CA practices. The main benefit perceived by farmers is
increased food availability, mainly through increased food
production, which is relevant as 65 % households are food
insecure in the area. However, it is important to note the
implication of the results in Figure 1 and the finding that only
6% of farmers adopted two CA practices in their main plots,
and that 0% are practicing three CA practices out of the
complete CA package. It shows that despite scientists seeing
practices as a package, farmers see and choose the individual
components.
It is thus essential to better understand both the incentives
and barriers to enhancing the adoption of the different
components in CA. Adoption is highly influenced by training
and farmer-to-farmer learning, hence farmer groups should
be promoted and sustained, and reward mechanisms put in
place for participants and trainers. Indeed, properly designed
extension activities as well as technical support to motivate
farmers towards the adoption of new practices and
technologies are essential. Farmer groups, involvement of
local level decision makers, and micro-credit schemes are
necessary to implement and up-scale sustainable land
management. It is important to link the promotion of specific
sustainable soil management and climate-smart practices
and technologies with sustainable extension services and
incentives (e.g. income generating activities, stable markets,
group learning, access to seeds of high-yielding or earlymaturing crops, and access to loans). The scaling-up of
promising sustainable soil management practices in different
farming systems is key to inform the design of future extension
programmes and investment plans.
References
Baker, John M., Tyson E. Ochsner, Rodney T. Venterea,
Timothy J. Griffis. “Tillage and soil carbon
sequestration—What do we really know?” Agriculture,
Ecosystems & Environment 118 (2007): 1–5.
Kimaro, A., Mpanda, M., Rioux, J., Aynekulu, E., Shaba, S.,
Thiong'o, M., Mutuo, P., Abwanda, S., Shepherd, K., Neufeldt,
H., Rosenstock, T. Is conservation agriculture 'climate-smart'
for maize farmers in the highlands of Tanzania? Nutrient
Cycles in Agroecosystems (2015)
Palm, Cheryl, Humberto Blanco-Canqui, Fabrice DeClerck,
Lydiah Gaterea, and Peter Graced. “Conservation agriculture
and ecosystem services: An overview”. Agriculture,
Ecosystems & Environment 187 (2014): 87–105.
Powlson, David S., Clare M. Stirling, M. L. Jat, Bruno G. Gerard,
Cheryl A. Palm, Pedro A. Sanchez, and Kenneth G. Cassman.
“Limited potential of no-till agriculture for climate change
mitigation”. Nature Climate Change 4 (2014): 678–683.
Nature & Faune Volume 30, Issue No. 1
93
Observations from the field: impacts of
conservation programming on community
livelihood strategies and local governance
structures in the eastern arc mountain range,
Tanzania
Dana M. Baker1
Summary
This research investigates the impact of conservation
programming on livelihood strategies and local governance
structures across selected sites in Tanzania. The research
presented is part of a larger global study, conducted in
collaboration with researchers at Yale's School of Forestry and
Environmental Studies, examining the factors that foster
replication, mainstreaming, and up scaling of conservation
and development projects across five countries.
Results in Tanzania show that conservation and development
interventions have various degrees of success and impact.
Within the scope of this study four key mechanisms that
positively influence conservation programming and
livelihood strategies will be discussed. These include: 1) the
negotiation and establishment of local level policies, 2) the
adoption of accountability and transparency mechanisms, 3)
the shift away from collective forms of governance to allow
stakeholders to profit on an individual basis, and 4) the
promotion of market integration and utilization. Yet, even with a
strong policy framework and international funding
surrounding natural resource management and development
programming there remain great challenges that impede the
sustainable use of Tanzania's natural resources.
Introduction
Over the last decade, community based approaches to
conservation and natural resource management have been
widely criticized for failing to deliver tangible benefits for either
the natural resource or the human community (Leach et al.
1999; Sheppard et al., 2010). This perception of failure has led
many to question the validity of an integrated approach to
conservation and development (Blaikie, 2006). Yet, the
interdependence of biodiversity conservation and poverty
alleviation mean neither can be effectively pursued in
isolation. Today, both remain central to the policy agendas of
developing states (Agrawal & Redford, 2006), despite the fact
there is little evidence, or pragmatic experience, on the impact
of conservation policies implemented around protected
areas (PAs)(Castillo et al., 2006; Clements et al., 2014).
Currently, policy choices are limited by an absence of
information regarding the impact of programming on local
livelihoods (Agrawal & Redford, 2006). This research seeks to
fill current gaps in literature by investigating the impact of
community conservation interventions on livelihood
strategies and local governance structures in Tanzania. Case
studies offer the opportunity for comparison and analysis of
the strengths of individual programs to successfully
implement conservation and development interventions.
Materials and methods
The area of study, namely the Eastern Arc Mountain Range in
Tanzania, encompasses some of the most important forest
blocks in Africa (Burgess et al., 2000). It is widely recognised
by international conservation organisations as a global centre
for flora and fauna endemism (Global Environment Facility,
2006). In addition to increased protection efforts by the
central government over the last two decades, a number of
interventions have sought to involve local communities more
directly in the management of forest resources (Ministry of
Natural Resources, 2001). Many such interventions are
focused directly on increasing the production of smallholder
farms adjacent to PAs through soil fertility management, agroforestry programming and small-scale irrigation schemes. Yet,
other interventions focus on diversifying livelihood strategies
to reduce the overall pressure on the region's natural
resources.
A multi-sited approach was used to conduct a comparative
analysis of the political, social, and environmental contexts of
conservation programming in 14 selected sites across
Tanzania located in three geographic areas of focus:
Kilimanjaro National Park, the Eastern Arc Mountain Range,
and Jozani National Park in Zanzibar. The scope of this paper
is on the findings from projects evaluated in the Eastern Arc
Mountain range, in which five of the sites were located. Study
site selection was determined by several variables, including
the focal area of the conservation intervention, time since
project completion, and proximity to a nature reserve. The
specific data and information collected at each site varied
based on the goal of an individual intervention. However,
indicators can be organized into four broad categories: 1.
Changes in socio-economic status 2. Capacity development
according to individual and institutional scales 3. Education
and awareness on issues of natural resource management,
and 4. Institutional and policy development.
Results and discussion
Conservation and development interventions across the
Eastern Arc Mountains are strengthening the link between
livelihoods, natural capital and poverty— a link that remains a
fundamental challenge to Tanzania's forest conservation
efforts. Four mechanisms were found to influence the
outcome of conservation interventions: First, the negotiation
and establishment of local level policies succeeded in
defining and enforcing the sustainable management of
natural resources within participating communities. Second,
the adoption of accountability and transparency mechanisms
enabled the design and the support of strong local
1
Fox Graduate Research Fellow,
University of Ghana, Institute of Environment and Sanitation Studies
P. O. Box LG25, Legon, Ghana, West Africa.
Email: [email protected],
Tel.: +14152355027
Nature & Faune Volume 30, Issue No. 1
94
institutions. Third, the shift away from a reliance on farmer groups allows farmers to produce and profit on an individual basis,
increasing the motivation to enforce sustainable land management practices. And last, the promotion of market integration and
utilization influenced positive conservation behavior by diversifying livelihood options for smallholder farmers.
The negotiation and establishment of local level policies helped secure water rights and land tenure across the mountain range
(Table 1). For example, new village level by-laws in communities outside Chome Nature Reserve state that farmers receiving
water from a newly built irrigation system must terrace their land and use agroforestry techniques. If a farmer does not agree to
implement such practices, they will not receive irrigation water from the new system. Such a policy reinforces the sustainability of
conservation programming by increasing the capacity of village governments to create and enforce sustainable behaviors.
Three years after the implementation of this policy, participating farmers report a 200% increase in crop yield (Source: SAIPRO
Agro Forestry Officer Monitoring Records, December 2012).
Table 1. Project name, implementing institution and summary of observed local level policy change with observed impact
Project evaluated in the Eastern Arc
Mountains: Name and Implementing
Organization
1.
Improving livelihoods of Nilo Nature
Reserve adjacent to local communities
through implementation of nonconsumptive activities.
Local Level Policy Change
(Yes/No)
Yes: Nilo Nature eRserve recently
upgraded from forest reserve to
nature reserve
changing local
access rights and policy.
3.
Sustainable Conservation of Chome
Nature Reserve through mepowermen t
and active ptiacr aitpio n of adjacent
communities.
Yes: Chome Nature Reserve was
recently upgraded to nature reserve
changing local access rights and
policy.
Implementing oragniz aotin: Tanzanian
Forest Conservation Group
Project designed and implemented
new land manag
ement plans and
policies.
Chome: Soil
conservation
and
environment management on the
highlands of Same District.
Implementing organization: SAIPRO
4.
Amani Butterfly Farming Project.
Implementing organization:Tanzania
Forest Conservation Group.
5.
Support to community involvement in
conserving biodiversity of Amani Natur e
Reserve, East Usambara Mountains.
Implementing organization: Amani Nature
Reserve
Conservation programming built relationships
with local community grouptshrough farmer
field scho osl, agro -forestry, and beekeeping
projects.
The elevat ed status of the reersve
has
restricted access to local communities
increasing pressure and land
degradation in
outside communities, stressing rela tionships
between stakeholders.
Implementing organization: Nilo Nature
Reserve
2.
Observed Impact
Yes: onfla
yrms
using soil
conservation techniques will get
water irrigated from new irgriation
system. Farms must have terraces
made by Dec. 2015.
No. Projecftocu ed
s
on market
integration and strengthening local
level institutions to ensure
transparency and accountability.
No policy change.
Project designed and implemented new landuse policies by formallymappin g local
resources. P lans strengthe ned the ability and
capacity of village governments to stop
encroachment and pumping of local springs
and water sources.
The elevat ed status of the
reserve has
restricted access to local communities
increasing pressure and land
degradation in
outside communities, stressing relati onsh ips
between stakeholders.
200% nicrea se in crop yield reported by
participating farmers. Strengthening of village
level authorities to enforce policy.
Project made 90,000 USD profit (2014).
Community development fund used to build tap
stands and expand electricity into partic ipati ng
villages. Community Development Fund and
revenue sharing scheme fundamental to
success, as is individual's ability to make profit.
Won Equator prize (2008). Project focused on
building demonstration plots and farmer field
schools to showcase bepsrtactic s, e agro forestry techniques, and beekeeping. Allowed
reserve management to build relationships with
community.
Engaging village governments to successfully create and apply local level policy, as seen in the villages surrounding Chome
and Nilo Nature Reserves, highlights the importance of decentralization in rule setting for conservation program success. Other
research supports the notion that the decentralization of authority is an important factor in improving program success, provided
that strong local institutions are present (Agrawal & Redford, 2006; Garnett et. al., 2007). Ostrom and Hayes (2005) note the role of
Nature & Faune Volume 30, Issue No. 1
95
decentralized decision-making for the success of PA's in a global review of forest conditions inside and outside reserves. Their
results show that forest conditions are related more closely to local involvement in setting rules on forest use than in any central
system of park designation.
The importance of building strong local institutions for the successful implementation of conservation programing is evident in
the communities surrounding Amani Nature Reserve. One enterprise development project, beginning in 2003, has grown from
an initial training of 10 farmers to include over 150 individual farmers. The project provides subsistence smallholder farmers with
a source of income that has minimal impact on the natural environment. Program activities have diversified livelihood strategies,
decreasing reliance on farming as a sole livelihood activity. Two mechanisms contribute to the projects' success. First, a clear
revenue sharing framework was established from the outset, whereby 28% of total sales are used for administration costs of the
project, 7% goes into a Community Development Fund, and 65% is returned to individual farmers who are paid up-front
according to each individual farmer's output. Individual farmers can see the direct financial impact from their effort—the more
time and effort an individual puts into their enterprise, the more money they make at the end of each month. Second, the
establishment of an elected committee that determines the groups' politics, finances, and marketing strengthens accountability,
program transparency, and trust between stakeholders. The elected committee additionally controls all stages of the valuechain, from producers to buyers, reducing reliance on intermediaries, thus increasing profits for all involved.
Many conservation and development interventions continue to rely on farmer groups and collective governance models, where
revenues generated are equally distributed throughout the group, despite some individuals not contributing and others putting
in more time and effort. Despite advantages to this collective model– such as lower capital investment, as well as lower
maintenance and labor costs, it is clear that farmers' individual productivity, and consequently the productivity of the entire
community, is seriously impaired by such arrangements. Problematic group dynamics were solved in both cases discussed
above through the creation of mandates allowing farmers to produce on an individual basis.
The role of market integration and utilization influencing conservation behavior is supported by the work of Stem et al. (2005).
They found that when a viable enterprise is linked to biodiversity of a protected area and generates benefits for individuals within
a community of stakeholders, stakeholders will act to counter the threats to the resource (Stem et al., 2005). However, known
conservation benefits from enterprise development could also be result of a learning process that strengthens local institutions
improving enforcement of the use of biodiversity, as well as the management of natural resources anda ecosystem services.
Conclusion
Projects evaluated here illustrate a diverse set of institutional arrangements between village level governments, national level
stakeholders, and international organizations. The study reports that the successful implementation of biodiversity conservation
and development interventions have to do with how communities are approached, the presence of strong local level
institutions, and the development and implementation of mechanisms that ensure transparency and accountability of project
funds. An interesting element that warrants further exploration is the move away from traditional approaches of collective
governance and farmers groups to allow farmers to produce and profit on an individual basis. Yet, even with a strong policy
framework and international funding surrounding natural resource management there are mounting challenges that impede
the sustainable use of Tanzania's natural resources. This paper
Photo 1. Communities outside Chome Nature Reserve have experienced a 200% increase in crop yield after the construction of
new irrigation channels and through the implementation of agroforestry and soil conservation techniques.
Photo credit: Dana Baker
Nature & Faune Volume 30, Issue No. 1
96
Photo 2. A butterfly farmer stands next to his butterfly cage in a community outside Amani Nature Reserve. The project started in
2003 with 10 trained farmers and has now grown to over 150 participating individuals across 6 villages. Strong project
leadership, transparency and accountability, and an established external market have significantly contributed to ongoing
program success. Photo credit: Dana Baker
Photo 3. Small-holder farms bordering Chome Nature Reserve in Tanzania demarking a clear boundary between forest and
agricultural lands. Photo credit: Dana Baker
References
Agrawal, A., & Redford, K. (2006). Poverty, Development, And Biodiversity Conservation: Shooting in the Dark? Wildlife
Conservation Society Working Paper, (26), 150.
Blaikie, P. (2006). Is Small Really Beautiful ? Community-based Natural Resource Management in Malawi and Botswana. World
Development, 34(11), 19421957. doi:10.1016/j.worlddev.2005.11.023
Burgess, N., Lovett, J., Mhagama, S., & Biodiversity, U. M. (2000). Biodiversity Conservation and Sustainable Forest Mangement of
the Eastern Arc Mountains. Draft Paper for the GEF Eastern Arc Strategy, 120.
Castillo, O., Clark, C., Coppolillo, P., Kretser, H., Mcnab, R., Noss, A., … Castillo, B. O. (2006). Casting for Conservation actors : people
partnerships and wildlife Casting for Conservation actors : People , Partnerships and Wildlife. Wildlife Conservation Society
Working Paper (28), November 2006, 1-98.
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Clements, T., Suon, S., Wilkie, D. S., & Milner-Gulland, E. J.
(2014). Impacts of Protected Areas on Local Livelihoods in
C a m b o d i a . Wo r l d D e v e l o p m e n t , 6 4 , S 1 2 5 S 1 3 4 .
doi:10.1016/j.worlddev.2014.03.008
Garnett, S. T., Sayer, J., & Toit, J. (2007). Improving the
Effectiveness of Interventions to Balance Conservation and
Development : a Conceptual Framework. Ecology and
Society, 12 (1), 2. Retrieved from
http://ibcperu.org/doc/isis/8563.pdf
Global Environment Facility. (2006). Conservation and
Management of the Eastern Arc Mountain Forests , Tanzania :
GEF-UNDP Eastern Arc Mountains Strategy Discussion
Document: July, 2006 (Vol.1).
Hayes, T., & Ostrom, E. (2005). Conserving the worlds forests:
Are protected areas the only way? Indiana Law Review, 38(3),
595.
Leach, M., Mearns, R., & Scoones, I. (1999). Environmental
entitlements: Dynamics and institutions in community-based
natural resource management. World Development, 27(2),
225247. doi:10.1016/S0305-750X(98)00141-7
Ministry of Natural Resources and Tourism. (2001). Action
Research into Poverty Impacts of Participatory Forest
Management: Selected Case Studies from the Eastern Arc
Mountains area of Tanzania. Global Environment Facility
Socio-economic Monitoring Programme, 1-149
Sheppard, D. J., Moehrenschlager, A., Mcpherson, J. M., &
Mason, J. J. (2010). Ten years of adaptive communitygoverned conservation: evaluating biodiversity protection
and poverty alleviation in a West African hippopotamus
reserve. Environmental Conservation, 37(03), 270282.
doi:10.1017/S037689291000041X
Stem, C., Margoluis, R., Salafsky, N., & Brown, M. (2005).
Monitoring and evaluation in conservation: a review of trends
and appraoches. Conservation Biology, 19(2), 295309.
Wilkie, D. (2007). Translinks Livelihood Surveys: A tool for
conservation design, action and monitoring. Wildlife
Conservation Society, 1-15.
Nature & Faune Volume 30, Issue No. 1
98
Analysis of sustainable livelihoods
diversification of marine fishing communities
in Benin
1
2
Katrien Holvoet , Denis Gnakpenou , and Rita Agboh
Noameshie3
Summary:
Marine fishing communities in Benin seek to diversify their
basic income because fishing is no longer providing enough
income to fully meet the household needs. Farmlands close to
communities can serve as new sources of income. Therefore,
market gardening has started gaining ground on sandy soils of
the beach and on the ferruginous, slightly saline soils in the
flood plains. To respond to the need for a sustainable
management of soils and water, AfricaRice, International
Fertilizer Development Center (IFDC) and the “Strategic
Response to HIV/AIDS for fishing communities in Africa4”
programme of the FAO are providing training and support for
the youth in efficient and sustainable use of lands and water.
The aim of this paper is to document how partners can use the
dynamics of the youth in fishing communities as innovators for
the introduction of efficient use of irrigation water combined
with aquaculture and improved varieties to obtain a high
income from rice farming and chilli production.
Two action-research protocols have been developed: one in
collaboration with the Africa Rice Centre (AfricaRice), aimed at
comparing rice varieties and the second in collaboration with
the IFDC, aimed at comparing market gardening techniques
and the combination of irrigation with the use of aquaculture
tanks.
The results of rice variety tests have helped to identify high
yielding rice varieties that can produce more than 5 tons/ha of
lowland rice and 3 tons//ha of rain-fed rice. On the other hand,
a comparison of irrigation systems for the production of NIKLY
variety of chili has shown that production was higher with drip
irrigation combined with the use of fish production tanks. The
yield of this double production reached 10.691 kg/ha for fresh
chilli fruits and a total of 56.5 kg of Clarias fish for one season.
Introduction:
Because of the unpredictability of fishing seasons and a
decrease in fish catches due to the impacts of climate change,
marine fishing communities in Benin have a growing interest
in diversifying their livelihoods. Simultaneously, these
communities are also grappling with the decrease in
agricultural production due to the salinity of underground
water used for irrigation. However, potentials in the
agricultural and aquaculture sector, technical innovations in
irrigation and sustainable soil management are unknown to
the participants in the fishing sector.
A study in mainly fishing communities, as documented in
5
2008 , revealed that these communities enjoy a relatively
satisfactory food diversity and security. However, households
who depend mainly on market gardening for their livelihoods
have better food security than fishing households, and more
frequently consume leafy vegetables.
There are strong gender issues encountered in the ongoing
livelihoods diversification within the fishing sector, which
have to do, among other things, with the allocation of
gardening work to women without them having any power on
the use of the revenues thereof. The majority of men prefer
keeping to their fishing activities, therefore diversifying
revenues with other activities becomes women's affair6.
Supporting fishing communities to enable them to diversify
their activities in terms of market gardening and rice-fish
production is essential to boost their food security and
diversity.
Materials and methods
Two studies were conducted:
1. Rice production study: It was decided to test rice
production in the Hio area (Ouidah commune) where rice has
never been produced before. Therefore, in 2008, the youth of
these households were involved in rice cultivar tests in order
to identify ideotypes and cultivars that are most adapted to
the types of soils through an assessment of their agromorphological characteristics, resistance to diseases and
insects, water table fluctuations, and salinity tolerance. A total
of 44 rice cultivars, including 12 rain-fed cultivars and 32
lowland cultivars were tested.
1
Katrien Holvoet Coordinator of the OPEC Fund for International
Development (OFID) funded and FAO executed Strategic Response to
HIV/AIDS for fishing communities in Africa Programme.
Email: [email protected]
2
Denis Gnakpenou, International Fertilizer Development Center (IFDC),
10 BP 1200 Cotonou, Benin.
Tel: (229) 21 30 59 90 / (229) 21 30 76 20 Fax: (229) 21 30 59 91
[email protected] [email protected]
3
Rita Agboh-Noameshie.
Interim Program Leader, Policy, Innovation Systems and Impact
Assessment Africa Rice Bénin, 01BP2031 Cotonou Republic of Benin
E-mail: a.agboh-noameshie @ cgiar.org
4
The programme formerly funded by SIDA, is now financed by the OPEC
Fund for International Development (OFID).
5
Food security and nutritional situation in 4 mainly fishing communities
in Benin; Maylis Razes, Marie Claude Dop ; Katrien Holvoet and Pierre
Coffi Galo ; FAO Fishing and HIV/AIDS Programme in Africa; 2010
6
Study on the irrigation systems used in market gardening in Southern
Benin and their impact on the competitiveness of the sector ;
Chrysogone K. Kassegne ; Denis Gnakpenou , IFAD 2014
7
Toward Sustainable Clusters in Agribusiness through Learning in
Entrepreneurship (2SCALE) is a project funded by the DGIS and
executed by IFDC
8
The NIKLY variety is produced by East West Seed International (EWIT), a
partner of 2SCALE
9
The products used are licensed in Benin and authorised for market
garden crops such as Pacha 25 EC and Acarius 18 EC
10
Confirmed by other producers who received fingerlings from the
same fish farmer at the same time with similar results
11
The daily average gain increased from 0.96g to 4.31g and 4.2 g
Nature & Faune Volume 30, Issue No. 1
99
The participation of the women started at the field
observations of the rice varieties till the final step on
organoleptic appreciation of the best performing varieties.
Women gave feedback to the community as shown in Plates 1
and 2.
research. Its fruits resemble those of the local cultivar which is
8
already appreciated in the market. The fruits of NIKLY are
relatively long and can quickly fill the basket used as a
measurement unit in the area.
The efficiency (irrigation duration, moisture depth in the soil,
water volume) and the cost effectiveness (cost of fuel for the
water pump, water volume) of the following irrigation systems
were compared
a. Micro spray irrigation
b. Irrigation with flexible pipes, the most widespread
technique in the area
c. Drip irrigation with water from an 8 m deep borehole
d. Drip irrigation with irrigation water from aquaculture
tanks used for the production of cat fish (Clarias
gariepinus). This system is being promoted by the
Fishery Production Directorate of Benin (Plates 3
and 4).
Plate 1: Rice: actors' assessment
Plate 3: Action-research chili
Plate 2: Female youth giving feedback to the community
on the rice trial
2. Chili pepper production study: In Grand-Popo, IFDC
through their programme 2SCALE7 has since 2012 been
conducting learning activities for beneficiaries in the chili
pepper production sector and identified chili pepper cultivars
that are (i) performing best, (ii) are adapted to the ecological
environment, and (ii) have an easy access to the market. They
introduced techniques for soil fertility management, nursery
establishment and management, nursery bed preparation,
nematode management, the use of anti-insect netting, best
practices for transplanting, harvesting, drying, storage and
processing chili into powder and the use of best irrigation
practices.
The youth of the Ayiguinou Association received training in
sustainable management practices and chose the NIKLY
cultivar, which is a hybrid and hotter cultivar, for the action-
Plate 4: Combination of market gardening with
aquaculture tanks
The water input for the aquaculture tank where Clarias are
produced, comes from the same source as the water for the
drip irrigation of crops. The Clarias were fed with provender
Nature & Faune Volume 30, Issue No. 1
100
(17% protein content) twice a day. Clarias are very resistant to stress caused by lack of oxygen, and has a growth (average daily
gain) of 5 to 8 g/day, making it possible to have fish of commercial size within 4 to 5 months.
The youth of the association received training in the use of aquaculture tanks for the production of Clarias gariepinus before the
start of the action-research. 165 fingerlings of 15 g were stocked a week before the transplanting of the chili and the start of the
drip irrigation. The water level in the aquaculture tank did not drop more than 15 to 20 cm, being topped up as the irrigation
proceeded.
The drip irrigation system consisted of round pipes of 16 mm diameter using internal tricklers distanced 20 cm from one another.
The pipes were placed at a distance of 40 cm apart on the beds, making two lines per bed. The system included three water
reservoirs: one 2 m3 reservoir which is directly connected to the water source and two 1.5 m3 reservoirs fed by the first reservoir.
One of the 1.5 m3 reservoirs served as aquaculture tank, supplying water to the drip irrigation system.
One week before the chili was transplanted, each bed of 3 m x 15 m received 50 kg of cow dung (about 11 t/ha). Two weeks after
the transplanting, each bed received 2.66 kg of NPK (about 600 kg/ha), and one week later, urea was applied at a dose of 200
9
kg/ha. Phytosanitary treatments were carried out in a systematic manner. Since the period of action-research coincided with the
dry season during which the risk of fungal infection is low, only insecticides were used.
Results and Discussion
Rice production study: The highest yields were recorded by lowland rice cultivars, such as IR 4630-22-2, WAS175-B-21-4 and
IR 69588-4RP-3-3, with yields higher than 5 tons per hectare, followed by rain-fed cultivars such as NERICA 4, NERICA 6 and
NERICA 15, with yields higher than 3 tons per hectare.
Chili pepper production study: The micro spray system gave a higher yield (9 562 kg/ha) as compared to the drip system (7 880
kg/ha) and the flexible pipe (6 866 kg/ha). When water from the fish production system was used for the drip irrigation system, the
yield increased to 10 691 kg/ha. This is 36% higher than the yield with drip using borehole water, but only 12% higher than with
micro spray irrigation. These yields are those recorded after 7 successive harvests over a period of 7 weeks. These results are
supported by the effect of the various irrigation systems on the average length and size of the fruits. The fruits harvested where
fish production water was used were longer (12 cm) and bigger in size (1.10 cm diameter) while those for which flexible pipes
were used were the smallest (10 cm and 1 cm length and diameter respectively).
Table 1 Chili yield and fruit size under different irrigation systems
Irrigation system
Micro spray
Drip with borehole water
Flexitubes
Drip with aquaculture
water
Yield
(kg/ha)
9 562
7 880
6 866
10 691
Chili yield parameters
Fruit size (cm)
Length
12
11
10
12
Diameter
1.1
1.0
1.0
1.1
Water consumption was lowest with the drip irrigation with 150 L per day being used. Micro spray used 286 L and the flexitubes
600 L per day. The combination of aquaculture and drip irrigation gave the lowest water consumption (140 L per day). The fuel
consumption for the pump was not recorded but more fuel is used with the flexitubes and with the micro spray. Because of the
larger quantities of water used by the micro spray and flexitube systems than by the drip system, the former two give lower water
use efficiencies (in terms of kg of chilli produced per m3 water applied) (Table 2). Thus when comparing micro spray with drip
irrigation using borehole water, the micro spray system would be best if available land was the most limiting factor and the drip
system if available water was the most limiting factor.
Nature & Faune Volume 30, Issue No. 1
101
Table 2. Chili yields, water used and water use efficiency under different irrifation systems
Irrigation system
Micro spray
Drip with borehole water
Flexitubes
Drip with aquaculture
water
Yield
(kg/ha)
Water used
(L/ha)
Water use efficiency
(kg/M3)
9 562
7 880
6 866
10 691
63.500 L/ha/day
33.300 L/ha/day
133.300 L/ha/day
31.300 L/ha/day
1.368
2.151
0.468
3.105
The higher yields obtained with the drip irrigation from
aquaculture water (see Table 2) can be explained by extra
organic matter and nutrients that are provided to the plants
from the fish tank waste waters can be explained by the better
retention of nutrients in the sandy soils due to the influence of
the organic matter and less leaching of nutrients from these
sandy soils that have low organic matter. Treatments with
higher water use (as in micro spray and flexitubes) cause
higher leaching of nutrients. This explains as well the more
efficient use of irrigation water.
The aquaculture tank used for irrigation helps to achieve the
best results for chili production and at the same time to have
56.5 Kg of fish (weight after 4 months).However, this low
aquaculture result is due to the bad quality10 of the
fingerlings11 and a 14% loss of them.
Acceptance and adoption of research outcomes: The rice
varieties with the highest yields were used in a degustation
and found suitable by the community. The research
outcomes of the chili-fish production led to requests by other
youths to receive a training in fish production and hatchery
management.
Conclusions and recommendations
The male and female youth in marine fishing communities are
facing the challenges of reduced catches and are eager to
establish sustainable alterative or complementary income
generating activities but they face major constraints Youth are
mobile and migrate and have often higher education levels
than their parents and are eager to explore new opportunities:
they were the first to bring the micro spray technology to
Grand Popo and understood from the cost-benefit analysis of
crop systems that there is a need to combine better
agricultural practices and water management. Factors
hampering or preventing the youth to be innovators are part
of the gender concerns (youth and women) such as their
access to financial capital to pay for the investments and their
access to land.
The future interventions should focus on a dialogue on
gender concerns and on both cash crops (chilly pepper) and
food crop (rice) that can be combined with aquaculture and
would be a complementary activity that would as well be
contributing to the strong position women have in fish
processing and marketing in the marine fishing communities.
Diversification in the chilli peppers and market gardening is
also improving the access to other vegetable production
such as leaf vegetables, tomatoes and local traditional
vegetables which are part of the rotation in the market
gardening. The practice could contribute to the nutrition
security at the household level and contribute to reducing the
chronic malnutrition of children under five years old in marine
fishing communities.
Promotion of rice-fish and vegetable-fish production in the
marine fishing communities should be strengthened. Water
efficient and environmental sound production systems are
available and should be taught and should result in increased
income and access to vegetables and fish as a protein source.
Diversification initiatives take into account a reduction in the
workload of women, equality in the management of income
and the provision of technologies to help (i) combine
aquaculture with agricultural production, (ii) reduce watering
time, (iii) practice a sustainable water management and, (iv)
use inputs (fertilisers and pesticides) efficiently.
Bibliography:
Chrysogone K. Kassegne ; Denis Gnakpenou , IFAD 2014 ;
Study on the irrigation systems used in market gardening in
Southern Benin and their impact on the competitiveness of
the sector ; internal report
Razes Maylis; Marie Claude Dop ; Katrien Holvoet and Pierre
Coffi Galo; 2010 ; Food security and nutritional situation in 4
mainly fishing communities in Benin; FAO Fishing and
HIV/AIDS Programme in Africa; working paper
Nature & Faune Volume 30, Issue No. 1
102
COUNTRY FOCUS: REPUBLIC OF CABO VERDE
Watershed management technologies to
boost the resilience of Cabo Verde to climate
change, and to mitigate the effects of
desertification
Jacques de Pina Tavares1
Summary
Desertification, due to recurrent droughts and soil
degradation, constitutes the major cause of the degradation of
the ecological fabric, and poverty in Cabo Verde. In order to
boost the resilience of the archipelago and ensure quality life
for its people in the midst of this phenomenon, a whole soil and
water conservation arsenal has been tested on the major
watersheds and watercourses of agricultural lands.
Reforestation, hydraulic structures, drip irrigation, improved
species and the involvement of communities are key steps to
reclaim these lands in the Sahel region. This approach has
resulted in more than 20% of the territory being reforested,
10,000 ha of farmland reclaimed and used, a strong
mobilisation of surface waters with the building of several
hydro-agricultural dams on the main agricultural islands, and
finally a significant improvement in the productivity of irrigated
lands. Certainly, spectacular results have been recorded over
the past 40 years, but this initiative is still ongoing as rain-fed
agriculture, which mobilises 90% of cultivated lands and the
majority of soil and water conservation technologies, is still
lagging behind irrigated agriculture, precipitations are
unreliable and soil erosion is still wreaking havoc in
ecosystems.
1. Introduction
The Cabo Verde archipelago is a small island state in the Sahel
2
region. It has a surface area of 4,033 km , and is located about
500 km from the Senegal-Mauritania coasts. The country is
made up of 10 islands and several volcanic islets (Figure 1). It
th
was uninhabited until it was discovered in the 15 century
(1462) by the Portuguese. Currently the population is about
500,000. The climate varies from sub-tropical arid to semi-arid.
The average annual precipitation is about 230 mm, with
significant disparities among the islands (13 mm in Sal as
compared to 323 mm in Santiago). There are no permanent
water sources in Cabo Verde. The volcanic soils on slopes
and tablelands, mostly used for rain-fed agriculture, are
underdeveloped, poor in organic matter (< 2%) but rather rich
in mineral nutrients. However, those on valley floors are very
deep and rich in organic matter.
1
Jacques de Pina Tavares.
Rural development researcher at the National Institute for Agrarian
Research and Development (INIDA) BP 84 Praia, Cabo Verde.
Email: [email protected]
Tel.: +238 271 11 27 and + 238 989 28 40 .
Fax: + 238 271 11 33
Figure 1: Geographical location of Cabo Verde
The degradation of the ecological fabric of the archipelago
through desertification started almost a century after it was
discovered and populated, resulting in a dire shortage of
water and fertile arable lands. This has an adverse effect on
food security, biodiversity, and has worsened the vulnerability
of the population. To remedy this situation, a whole arsenal of
measures and soil and water conservation structures have
been introduced and tested. These interventions have been
modelled with watershed areas depending on the complexity
of the topography and the diversity of bioclimatic zones. This
study aims to sum up these protection measures and assess
their impacts.
2. Reforestation
Successive and recurrent droughts, coupled with
anthropogenic pressure on natural resources, have led to a
considerable decrease in the vegetative cover. When Cabo
Verde became independent in 1975, only about 5,000 ha of
land were afforested as compared to 89,000 ha currently
(Figure 2 ), thanks to the momentous efforts made by the state
with the support of the international community and the
strong mobilisation of the civil society. The main woody
species planted are: prosopis sp. (61 %) and acacia sp. (6.3 %).
Figure 2: Trend in afforested areas over time (ha)
Nature & Faune Volume 30, Issue No. 1
103
3. Live vegetative barriers
Live vegetative barriers are used on a range of the most arid to the most humid slopes, along elevation contours, from the top to
the base of slopes. Their biophysical and socioeconomic impacts are considerable and numerous (Table 1 ).
Table 1: Plant species used as live barriers and their effects on the soil
Effects on soil qualities
Plant species
Aloe vera
Leucaena leucocephala
Cajanus cajan
Furcraea gigantea
Prosopis juliflora
Soil
fertility
Fair ly high
Very high
Very high
Fairly high
Very high
Fodder
Maize
Water
Sedimentation*
production production infiltration
(cm.yr-1)
None
High
Excellent
2.75
Very high
Very high
Good
1.85
Fairly high
Very high
Good
1.70
None
Fairly high
Good
Fairly high
Low
Good
-
*The sedimentation corresponds to the retained soil behind the live vegetative barriers.
4. Main watershed management and torrent control structures
To ensure the establishment of arborized species, stabilise watershed soils and improve the yield of rain-fed crops, several
techniques have been employed (Table 2 ). The main objectives are to harness rainwater, to replenish groundwater and reduce
the destructive force of surface run-off. .
Table2: Main land management techniques
Impacts
Technique
Ecosystem
where used
Soil
Runoff
stabilization reduction
Installation Durability and scale
of impact
cost
Contour ridges
Slopes
Low
Good
Acceptable
Long term /high
Half-moons
Slopes
Low
Good
Acceptable
Long term/moderate
Contour stone walls
Slopes
Good
Fairly good
High
Medium term/high
Bench terraces
Slopes
Very good
Good
Very high
Long term/Moderate
Check-dams
Watercourse
Very good
Very good
Very high
Short term/high
Dry stone flood barriers
Watercourse
Very good
Very good
High
Short term/high
Gabion flood barriers
Watercourse
Very good
Very good
High
Dry stone walls
Watercourse
Good
Low
High
Short term/moderate
Medium
term/moderate
5. Main water storage technologies
On average, 78 % of water consumed in Cabo Verde comes from groundwater, and the remaining 22% is desalinated sea water.
Some of the islands, such as Sal and São Vicente, are largely served with desalinated sea water at the rates of 100 and 58%
respectively (Table 3). Rainwater is also harnessed by means of rainwater cisterns where rainwater is directly harvested from the
roofs of houses. This technique is widespread on the Fogo Island. There is also another form of harvesting and channelling
rainwater locally known as “espelho de captação”. This system is made up of three elements: an impluvium made with bricks and
cement on a slope which is used to harvest the water, then this water is channelled to a downstream reservoir through a channel.
Nature & Faune Volume 30, Issue No. 1
104
Table3 : Proportions of various sources of water used on different islands
Proportion of water used from different sources (%)
Island
Santo Antão
São Vicente
São Nicolau
Sal
Boa Vista
Maio
Santiago
Fogo
Brava
Underground
Desalinated
Treated
wastewater
Surface
runoff
98
29
100
0
88
100
87
100
100
2
58
0
100
12
0
10
0
0
0
13
0
<1
0
0
<1
0
0
0
0
0
0
0
0
3
0
0
Source: Adapted from PENAS (2013)
6. Impacts of land management and water mobilisation technologies
The stabilization of watershed soils and torrent control in watercourses has helped to create, rehabilitate and reclaim close to
8,000 ha of rain-fed farmland and more than 2,000 ha of irrigated farmland (Error! Reference source not found.). This way of
adding value to land plays an important role in the food security of rural families because about 45% of the population live in rural
areas.
Figure3: Increase in cultivated land areas from 1995 to 2013 (ha)
This increase in cultivated area, together with the improved water conservation measures, has helped to significantly improve in
less than 13 years the production of fruit from 10,000 tons to more than 16,000 tons, vegetables by more than 300% and market
garden products from 5,651 to 44,180 tons (Figure 4). Grape production has increased nearly fourfold in ten years, from 104 tons
in 2004 to 385 tons in 2014 (Ministry of Rural Development Report , 2015). These results have enabled the people of the
archipelago to have these products throughout the year on the market, which was not possible in the early 1990s.
Nature & Faune Volume 30, Issue No. 1
105
P (tons)
Figure4: Increase in the production on irrigated lands between 1991 and 2013 (tons)
More than 90 % of irrigation water is from underground sources, notably springs, wells, boreholes and galleries in the proportions
of 43.7, 25.8, 17.9 and 3.6 % respectively (RGA, 2004). To reduce the pressure on these sources, a strong surface water
mobilisation policy has been put in place since the early 2000s, capturing 78% of the investment programme (MDR, 2015b).
According to the hydrological balance, about 87 % of these waters (180.106 m3 per year) run off into the sea where they are lost
through evaporation. From 2006 to 2015, more than ten hydro-agricultural dams capable of mobilising about 250. 106 m3 water
for irrigating more than 400 ha of land were built. At the same time, other technologies such as drip irrigation and crop cultivars
more adapted to arid conditions were approved for usage (INIDA, 2014). Glasshouse crops, improved animal races, and plant
protection solutions that are simpler and more accessible to farmers have also been approved for use. However, the heavy
dependence on rain-fed agriculture and current rainfall patterns have slowed down results achieved (Figure 5) even though the
many soil and water conservation technologies have been developed.
Figure5: Variation in maize production over (tons). Adapted from Ministry of Rural Development Report, 2015
7. Conclusions
The tremendous water conservation and land reclamation efforts made by Cabo Verde since its independence in 1975 have
produced very encouraging results in the recovery of the ecological fabric of these Mars-like islands. Droughts had taken a huge
toll on the population by decimating more than half of it. Those who fled the country found refuge in other countries in Africa, the
United States and Europe. Today, although droughts still persist, their adverse effects are almost non-existent. After centuries of
unwavering fight against harsh and complex weather conditions, Cabo Verde has recently been able to find some solutions or
technologies needed to deal with the scarcity of arable land and water, and ensure the well-being of the people. However, the
country is still grappling with the quest for cultivated lands, and the problems of soil erosion, scarcity of rains, the pressure on
underground waters, the salinity of some ground waters, and fodder scarcity.
Nature & Faune Volume 30, Issue No. 1
106
Bibliography
Ferreira, A., Tavares, J., Baptista I., Coelho, C., Reis, A., Varela, L.,
Bentub, J., 2012. Efficiency of overland flow and erosion
mitigation techniques at Ribeira Seca watershed, Santiago
Island, Cabo Verde. In Overland Flow and Surface Runoff.
Hydrology Science and Engineering. Ed. Tommy S.W.Wong
(113-135).
INIDA, 2014. Report of the activities carried out in the
framework of the program: The applied agricultural research
and knowledge transfer, pp 7.
MDR (Ministry of Rural Development), 2015a. Estimation
report of agricultural and livestock production. Direction of
statistics and information management, pp. 26.
MDR, 2015 b. Mobilization and Water Management. Edition n°
6 – July 2015.
PENAS, 2013. Environmental and Social National Strategic
Plan. Ministry of Finance and Planning, pp, 69.
RGA, 2004. Census of Agriculture. Ministry of Environment,
Agriculture and Fisheries. CD Rom. Cabo Verde.
Nature & Faune Volume 30, Issue No. 1
107
FAO ACTIVITIES AND RESULTS
Key messages on soils from the Forestry
Department of Food and Agriculture
Organization of the United Nations
1. Climate change: what forests and forest soils do
Carbon emissions are a major contributor to climate change.
The world´s forests, in one of their many roles, act as a
significant carbon store. 650 billion tonnes of carbon, or
nearly one third of the total in terrestrial ecosystems, are
captured in forests. Forest soils also store a quantity of carbon
equalling that of the global forest biomass, about 45 percent
each. An additional ten percent of carbon is found in forest
dead wood and litter. In total, forests store as much carbon as
the atmosphere.
2. Sustainable soil management needs sustainable forest
management, including restoration
The planet needs sustainably managed forests to control soil
erosion and to conserve soil. Tree roots stabilize ridge, hill and
mountain slopes and provide the soil with the necessary
mechanical structural support to prevent shallow
movements of land mass: landslides rarely occur in areas with
high forest cover.
Sound forest management practices, including measures to
introduce or maintain forest cover on erosion-prone soils and
run-off pathways, will help control or reduce the risk of soil
erosion and shallow landslides. Forest restoration in dryland
areas is vital for soil protection.
3. Major ecosystem benefits of forests and soils: clean
water and watershed management
By reducing soil erosion and the risk of landslides and
avalanches, sustainably managed forests contribute
significantly to the systems providing and maintaining the
planet's supplies of clean water, while also ensuring a
balanced water cycle. Forests are also a key component of
watershed management – an integrated approach of using
natural resources in a geographical area drained by a water
course. Watershed management is a very sound way to
protect and rehabilitate areas prone to soil degradation and
erosion in upland areas. Forest and soil characteristics are
among the key parameters assessed in watershed
management planning. Moreover, measures to restore and
enhance soil fertility, e.g. through reforestation, have many
benefits and are therefore an integral part of any watershed
management plan.
4. Soil conservation in semi-arid and arid areas starts with
forests and trees
By helping to prevent soil erosion, forests act as a crucial
protector of soil resources, for example in preventing or
reducing salinization. The challenge in arid-zone forests is
therefore to optimize the trade-offs, between water yield and
soil protection.
5. Forests can reduce mountain soils' sensitivity to
degradation
Steep slopes and thin soil make mountain ecosystems
extremely vulnerable to erosion. Mountain soils are often
degraded and invariably do not provide enough nutrients for
plants to grow well. FAO estimates that around 45 percent of
the world's mountain area is not or only marginally suitable for
agriculture. The degradation of mountain soil and vegetation
cover may happen gradually or rapidly but often takes many
years to repair; in some cases it is irreversible.
The challenges that mountain farmers must overcome are
many: short vegetation periods, steep slopes, shallow soils
and the occurrence of landslides. To survive, they have had to
develop different ways of averting or spreading risks,
employing complex and diversified farming systems on
croplands, pastures and forests. They know that they must
make use of different soil types at different altitudes and at
different times of the year.
Source
:
http://forestry.fao.msgfocus.com/files/amf_fao/project_59/A
pril_2015/Soils_Key_messages_revisions_Thomas20April_
Final_clean_.pdf
Contact:
Maria De Cristofaro, Communications Officer
Nature & Faune Volume 30, Issue No. 1
108
Promoting sustainable soil management in
sub-saharan Africa through the African Soil
Partnership
Liesl Wiese1, Craig Chibanda2, Victor Chude3, Ronald
Vargas4 and Lucrezia Caon5
Summary
In Sub-Saharan Africa, soil degradation leads to a massive
annual loss of productive soils and is the root cause of
declining agricultural productivity. If soil degradation is
allowed to continue, it will have severe negative impacts on
the economies of individual countries and the welfare of
millions of rural households dependent on agriculture for their
livelihoods. The Global Soil Partnership (GSP) was established
in 2012 to promote sustainable soil management (SSM) at all
levels. Regional Soil Partnerships were established in order to
facilitate regional actions and to ensure that the partnership
process becomes country driven. The Steering Committee of
the African Soil Partnership (AfSP) identified priorities for SSM
promotion and implementation under the five Pillars of Action
of the GSP. The International Year of Soils has triggered various
actions at regional and national levels, for instance regional
and national workshops were organized as well as many other
social and educational activities. The implementation of the
GSP plans of action will focus on SSM in the region for the
purpose of fighting hunger and poverty, adapt and mitigate to
climate change and ensure the provision of other ecosystem
services by soils (e.g. clean water). However, soil degradation
remains an issue in the region, which is in need of further
support from the GSP and the international community.
Investments in SSM and soil and land rehabilitation are seen as
the only solutions to improve soil health and therefore the
welfare of millions of people.
adoption of sustainable soil management (SSM) among
smallholder farmers is the lack of information and knowledge
(FAO, 2011). Up to date there are not reliable data on the
extent and rate of soil degradation in SSA (Tully et al., 2015),
however it has been estimated that an area of five to eight
million hectares of formerly productive land goes out of
cultivation annually due to degradation globally (TerrAfrica,
2007). In order to reverse soil degradation it is important to
develop indicators to estimate and monitor the status of soil
health and promote SSM (Tully et al., 2015). The objective of
this paper is to discuss the progressive adoption of SSM in
SSA through the African Soil Partnership (AfSP) and the way
forward to curb soil degradation in the region.
The Global Soil Partnership
The Global Soil Partnership (GSP) was established and
formally endorsed by FAO member countries in 2012 to
create a unified and recognized voice for promoting SSM at all
levels. Therefore, the establishment of the GSP relies on the
need to have an international governance body advocating
for SSM in global change dialogues and decision making
processes. In order to achieve its objectives, the GSP
addresses 5 pillars of action: (1) promote sustainable
management of soil resources for soil protection,
conservation and sustainable productivity, (2) encourage
investment, technical cooperation, policy, education
awareness and extension in soil, (3) promote targeted soil
research and development focusing on identified gaps and
priorities and synergies with rel ated productive,
environmental and social development actions, (4) enhance
the quantity and quality of soil data and information, and (5)
harmonization of methods, measurements and indicators for
the sustainable management and protection of soil resources.
Introduction
To feed its growing population, Sub-Saharan Africa (SSA) is
intensifying and expanding its agricultural production (Tully
et al., 2015). However, the region has the lowest agriculture
and livestock yields of the world due to soil degradation (IFAD,
2009). Soil degradation is defined as “the diminishing
capacity of the soil to provide ecosystem goods and services
as desired by its stakeholders” (FAO and ITPS, 2015). It
manifests in various forms such as the loss of organic matter
and adverse change in salinity, acidity or alkalinity (Tully et al.,
2015). Soil degradation is specifically recognized by both
policy makers and soil specialists as one of the root causes of
declining agricultural productivity in the region where 75
percent of the population depended on subsistence farming
at the end of last century (Lal, 1990; Tully et al., 2015; UNEP,
1982). Should this trend be allowed to continue, the effect on
the economies of individual countries and the welfare of
millions of rural households dependent on agriculture for their
livelihoods will be severe (FAO, 1999).
One of the main obstacles to reducing land degradation,
improving agricultural productivity and facilitating the
1
Liesl Wiese. Consultant/Soil Science Researcher,
Email: [email protected]
2
Craig Chibanda. Family Farming Knowledge Platform, Consultant Regional Focal Point for Africa, Office of Partnerships, Advocacy and
Capacity Development (OPC), FAO Regional Office for Africa, Food and
Agriculture Organization of the United Nations,
P. O. Box GP 1628 Accra, Ghana.
E-mail: [email protected]
Tel: +233 (0)302610930 Ext. 42127
3
Victor Chude. Soil fertility specialist,
Head: Agriculture Productivity Enhancement, National Programme for
Food Security, Federal Ministry of Agriculture, Nigeria
Email: [email protected]; and [email protected]
4
Ronald Vargas. Technical Officer,
Food and Agriculture Organization of the United Nations, Viale delle
Terme di Caracalla, Rome, 00153, Italy.
Email: [email protected]
5
Lucrezia Caon. Consultant, (Corresponding author)
Food and Agriculture Organization of the United Nations, Viale delle
Terme di Caracalla, Rome, 00153, Italy.
Email: [email protected];
Tel.: +39 06 57053836
Nature & Faune Volume 30, Issue No. 1
109
In order to facilitate regional actions, Regional Soil
Partnerships were established among interested and active
stakeholders with the aim of building on existing regional
networks or collaborative processes, linking national and
local networks, partners, projects and activities to ensure that
the partnership process becomes country driven (FAO,
2015a).
One of the core activities of the GSP has been the revision of
t h e Wo r l d S o i l C h a r t e r ( W S C ) o f 1 9 8 1 b y t h e
Intergovernmental Technical Panel on Soils (ITPS) (FAO,
2015b). The need to revise the WSC was identified to adjust
the focus of the document from land use planning and land
evaluation (FAO, 1982) to key concepts such as the
framework of ecosystem services provided by soil. The
revised version of the WSC was endorsed during the 39th FAO
Conference in 2015 as a vehicle to promote and
institutionalize sustainable soil management at all levels (FAO,
2015c). 2015 is important to soils especially because it was
declared the International Year of Soils (IYS) by the 68th UN
General Assembly (A/RES/68/232) for the purpose of serving
as platform for raising awareness of the importance of soils for
food security and essential eco-system functions under the
GSP framework (FAO, 2015d). According to FAO (2015d), the
objectives of the IYS are (i) to create full awareness by civil
society and decision makers about the fundamental roles of
soils for human's life, (ii) to achieve full recognition of the
prominent contributions of soils to food security, climate
change adaptation and mitigation, essential ecosystem
services, poverty alleviation and sustainable development,
(iii) to promote effective policies and actions for the
sustainable management and protection of soil resources, (iv)
to sensitize decision-makers about the need for robust
investment in sustainable soil management activities aiming
at healthy soils for different land users and population groups,
(v) to catalyze initiatives in connection with the SDG process
and Post-2015 agenda, and (vi) to advocate rapid
enhancement of capacities and systems for soil information
collection and monitoring at all levels (global, regional and
national).
At the United Nations Sustainable Development Summit on
25 September 2015, world leaders adopted the 2030 Agenda
for Sustainable Development and therefore endorsed a set of
17 Sustainable Development Goals (SDGs) to end poverty,
fight inequality and injustice, and tackle climate change by
2030 (UNDP, 2015). For the first time in history, soils were
included and explicitly mentioned in the development
agenda:
Ÿ
Goal 2, target 2.4: “by 2030, ensure sustainable food
production systems and implement resilient agricultural
practices that increase productivity and production,
that help maintain ecosystems, that strengthen capacity
for adaptation to climate change, extreme weather,
drought, flooding and other disasters and that
progressively improve land and soil quality”;
Ÿ
Goal 3, target 3.9: “by 2030, substantially reduce the
number of deaths and illnesses from hazardous
chemicals and air, water and soil pollution and
contamination”;
Ÿ
Goal 15, target 15.3: “by 2030, combat desertification,
restore degraded land and soil, including land affected
by desertification, drought and floods, and strive to
achieve a land-degradation-neutral world” (UNDP,
2015).
This is considered a great achievement in the way forward
toward the broad adoption of sustainable soil management.
The African Soil Partnership
It was decided to establish eight regional soil partnerships
under the umbrella of the GSP with the task of provide
guidance on regional goals and priorities (FAO, 2015f). North
African countries (Algeria, Egypt, Libya, Morocco, Sudan and
Tunisia) respond to the Near East and North Africa Soil
Partnership. Thus, the African Soil Partnership includes only
countries in Sub-Saharan Africa.
The African Soil Partnership (AfSP) was launched in Western
and Central Africa in March 2013 (Accra, Ghana), and in
Eastern and Southern Africa in April 2013 (Nairobi, Kenya).
The AfSP was then consolidated at the first African Soil
Partnership (AfSP) Workshop in May 2015 (Elmina, Ghana).
During the Elmina workshop the AfSP Steering Committee
was established for guiding AfSP implementation and the
Elmina Communiqué was compiled in order to consolidate
the institutional mechanism of the AfSP, list the intentions of
the Partnership in terms of addressing sustainable soil
management and related issues in the region, and commit to
completing the Implementation Plan for the region (FAO,
2015e).
The AfSP and a range of national and regional partners of the
GSP are currently developing a regional Implementation Plan
for the purpose of setting the priorities and medium term
outcomes and activities for the SSA region. Priorities for SSM
in the SSA region are developed under the umbrella of the five
Pillars of Action of the GSP and rely on the definition of SSM as
proposed by the revised WSC (FAO, 2015c). Therefore,
priority is given to (i) assess and document soil degradation
status and trends, the potential for agriculture for major agroecological zones, land use systems and existing SSM
practices, (ii) develop a monitoring system to measure
progress of implementation of SSM practices and systems, (iii)
upscale proven successful SSM practices, (iv) establish and
strengthen National Soil Science Societies in all
countries/sub-regions, (v) revitalize the African Soil Science
Society and its website for active information sharing, (vi)
create Sustainable Soil Management partner platforms, (vii)
develop regional exchange programmes for tertiary soil
science training, along with an associated bursary scheme,
(viii) repackage soil information for extension programmes,
(ix) propose region-specific policies and strategies that
countries can adopt, (x) develop a website/page for research
Nature & Faune Volume 30, Issue No. 1
110
and development priorities, (xi) assess and prioritize soilrelated research gaps, (xii) set up regional working groups for
specific research themes with clear terms of reference, (xiii)
establish African Soil Research for Development Platforms,
(xiv) document soil data sources and soil mapping covariates,
(xv) develop a comprehensive soil database and an online
interaction platform for digital soil mapping (DSM), (xvi)
conduct DSM training and capacity building, (xvii) produce
digital maps of soil texture as initial digital mapping products
for the region, (xviii) regularly update soil databases, (xix)
develop a common harmonization concept for soil
description and classification at regional level, (xx) GSP/FAO
to revitalize the regional soil correlation events that used to be
organized, (xxi) identify national, regional and international
reference laboratories for training, soil analyses and soil
sample exchange, and (xxii) develop a framework to indicate
how individual country or regional soil data can be shared
with others.
Conclusion
Sub-Saharan Africa is affected by different forms of soil
degradation that lead to a massive annual loss of productive
soils and are the root cause of declining agricultural
productivity in the region. If soil degradation is allowed to
continue, it will have severe negative impacts on the
economies of individual countries and the welfare of millions
of rural households dependent on agriculture for their
livelihoods. Through the establishment of the GSP and
therefore the activities promoted at national and local level by
the AfSP, much was done to sensitize the population on the
importance of preserving and improving soil health and on
the need to adopt sustainable soil management in order to
fight poverty and hunger. However, the many projects and
activities launched in the region since the establishment of
the partnership were not sufficient to tackle the numerous
problems affecting sub-Sahara African soils. Soil degradation
remains an issue in the region, which is in need of further
support from the GSP and the international community.
Investments in sustainable soil management and soil and
land rehabilitation are seen as the only solutions to improve
soil health and therefore the welfare of millions of people.
References
FAO, 1982. World Soil Charter
FAO, 1999. Integrated Soil Management for Sustainable
Agriculture and Food Security in Southern and East Africa.
Agritex AGL/MISC/23/99.
FAO, 2011. Sustainable Land Management in PracticeGuidelines and Best Practices for Sub-Saharan Africa. Liniger,
H.P., Studer, R.M., Hauert, C. and Gurtner, M. (eds.). ISBN 97892-5-000000-0
FAO and ITPS, 2015. Status of the World's Soil Resources.
Food and Agriculture Organization of the United Nations
(available on December 2015)
FAO, 2015a. The 5 pillars of action ()
FAO, 2015b. Intergovernmental Technical Panel on Soils
(ITPS) ( )
FAO, 2015c. Revised World Soil Charter ()
FAO, 2015d. International Year of Soils 2015- IYS 2015 ( )
nd
FAO, 2015e. Elmina Communiqué – Elmina (Ghana), 22 May
2015 - ()
FAO, 2015f. Regional Soil Partnerships
(http://www.fao.org/globalsoilpartnership/regionalpartnerships/en/)
IFAD, 2009. The Strategic Investment Program for Sustainable
Land Management in Sub-Saharan Africa ()
Lal, R., 1990. Soil erosion and land degradation: The global
risks. In R. Lal and B.A. Stewart (eds.), Soil degradation, New
York, Springer-Verlag, pp. 129-172.
TerrAfrica, 2007. Assessment of the barriers and bottlenecks
to scaling-up SLM investments throughout Sub Saharan
Africa. TerrAfrica SIP Activity 1.4.
Tully, K., Sullivan, C., Weil, R., Sanchez, P., 2015. The state of
soil degradation in sub-Saharan Africa: baselines, trajectories,
and solutions. Sustainability 7:6523-6552
UNDP, 2015. Sustainable Development Goals (SDGs) ()
UNEP, 1982. World's soil policy, Nairobi, Kenya: United
National Environment Programme.
Nature & Faune Volume 30, Issue No. 1
111
LINKS
Five reasons why soil is key to the planet's
sustainable future
1. Healthy soil feeds the world
Soil is where food begins. Composed of minerals, water, air
and organic matter, soil provides primary nutrient cycling for
plant and animal life and acts as a basis for feed, fuel, fibre and
medical products as well as for many critical ecosystem
services.
To explore further visit: http://www.fao.org/soils-2015/en/
2. Soil, like oil or natural gas, is a finite resource
Soil is non-renewable – its loss is not recoverable within a
human lifespan. It can take hundreds to thousands of years to
form one centimetre of soil from parent rock, but that
centimetre of soil can be lost in a single year through erosion.
Poor farming practices - extensive tilling, removal of organic
matter, excessive irrigation using poor quality water and
overuse of fertilizers, herbicides, and pesticides - deplete soil
nutrients faster than they are able to form, leading to loss of soil
fertility and degrading soils. Some experts say the number of
years of top soil left on the planet is comparable to estimates
for reserves of oil and natural gas. At least 16 percent of African
land has been affected by soil degradation. And globally,
50,000 square kilometres of soil, an area the size of Costa Rica,
is lost each year, according to the Global Soil Partnership. For
further information on Global Soil Partnership visit:
http://www.fao.org/globalsoilpartnership/en/
3. Soil can mitigate climate change
Soil makes up the greatest pool of terrestrial organic carbon,
more than double the amount stored in vegetation. As well as
helping to supply clean water, prevent desertification and
provide resilience to flood and drought, soil mitigates climate
change through carbon sequestration and reduction of
greenhouse gas emissions. "Soils of the world must be part of
any agenda to address climate change, as well as food and
water security,” says Rattan Lal, Director of Ohio State
University's Carbon Management and Sequestration Center"
For more about Carbon Management and Sequestration
Center visit: http://cmasc.osu.edu/pageview2/Home.htm
4. Soil is alive, teeming with life
A quarter of the planet's biological diversity exists in soil. There
are literally billions of microorganisms such as bacteria, fungi,
and protozoans in the soil, as well as thousands of insects,
mites and worms. More organisms are contained in one
tablespoon of healthy soil than there are people on the planet.
"It's only been recently that we've begun thinking about soil
biodiversity as a resource we need to know something about,"
says Diana Wall, Scientific Chair of the Global Soil Biodiversity
Initiative. “Without soil and their biodiversity, there is no
human life.” Further information about the Global Soil
Biodiversity Initiative on: https://globalsoilbiodiversity.org/
5. Investing in sustainable soil management makes
economic and environmental sense
Managing soil sustainably is cheaper than rehabilitating or
restoring soil functions. A FAO-led project focusing on land,
water and biological resources to reverse the process of land
degradation in the Kagera river basin between Burundi,
Rwanda, Uganda and Tanzania has improved the livelihoods
and food security of farmers around Lake Victoria. To access
State of the Art Report on Global and Regional Soil Information
f o l l o w
t h e
l i n k :
http://www.fao.org/fileadmin/user_upload/GSP/docs/report/
Soil_information_Report.pdf
Further information about soils can be found at:
h t t p : / / w w w. f a o . o r g / p o s t - 2 0 1 5 - m d g / n e w s / d e t a i l news/en/c/277113/
Nature & Faune Volume 30, Issue No. 1
112
NEWS
African Soil Partnership
A 3-day workshop on the Africa Soil Partnership (AFSP) jointly organised by the Global Soil Partnership and the FAO Regional
Office for Africa, took place from the 20-22 May 2015 at the Coconut Grove Beach Resort, Elmina. Ghana. The workshop was
attended by participants from 35 Subsaharan Africa countries. Opening the workshop Mr. Bukar Tijani (Assistant DirectorGeneral/Regional Representative for Africa, Regional Office for Africa, United Nations Food and Agriculture Organization)
challenged participants to perceive the workshop as a platform to give voice to the critical issues at stake. He added that from the
Abuja Declaration of 2006 a lot needs to be done - identifying existing gaps and sharing ideas on innovative ways to move
forward.
Participants meet at Elmina, Ghana to form the African Soil Partnership, May 20-22, 2015.(Photo courtsey David Young)
Mr Thiombiano the moderator for the workshop remarked that if the world is celebrating the International Year of the Soils, it is
because it is gradually coming to the realisation that indeed the soil is a vital resource without which life cannot continue. The
th
declaration of 5 December each year by the UN General Assembly as World Soil Day shows that increasingly the world is
coming to see the dynamic role that soils plays especially in the fight against climate change and maintaining a sustainable
environment. He added that there is a bright opportunity for soil scientists to make sure they take advantage of the current
platform to give soils the much needed recognition.
Mr Ronald Vargas from United Nations Food and Agriculture Organization headquarters in Rome emphasized the need for a
strong partnership for Africa. He explained that the mandate of the Global Soil Partnership is to improve governance of the limited
soil resources of the planet in order to guarantee healthy and productive soils for a food secure world, as well as support other
essential ecosystem services, in accordance with the sovereign right of each State over its natural resources. He stressed the
need for inclusive policies and governance, investment in sustainable soil management targeting soil research and capacity
building especially training younger people.
National presentations were made on the status, needs and priorities for sustainable soil management in sub-Saharan Africa
(SSA). Soil erosion, land degradation, poor capacity building, inadequate soil information and lack of harmonisation were
identified among the challenges facing soil resource management in SSA. The workshop also supported the finalisation of a
draft regional implementation plan. In all five working groups were formed to look at identifying activities that would fit into the
Five Pillars of Actions by the GSP.
The establishment of a steering committee and its terms of reference were seen as a great milestone for the partnership. Two
people were selected from each sub region and two others to represent the International Institute of Tropical Agriculture (IITA)
and the African Soil Science Society (ASSS). Professor Victor Chude was appointed as the chair of the committee. To facilitate
activities of the AFSP, FAO regional office for Africa volunteered to host the secretariat. Mr Brahene Sebastian
([email protected]) and Ms Liesl Wiese ([email protected] ) were appointed to be in charge of the secretariat.
Nature & Faune Volume 30, Issue No. 1
113
Nominated members of the Steering Committee of the Africa Soil Partnership (Photo courtsey David Young)
The issuing of the Elmina communiqué was seen as a very
important step in communicating to the world, Africa's
preparedness to take up the challenges that threaten soil
resources and also to encourage governments and other
stakeholders to honour their commitments to support SSA to
deal with the challenges of climate change which threaten
agriculture and livelihood.
Information on the workshop can be obtained from:
http://www.fao.org/globalsoilpartnership/highlights/detail/e
n/c/288450/
http://www.fao.org/globalsoilpartnership/regionalpartnerships/africa/en/
Food forests could help end hunger for nomads in arid
East Africa
Training Samburu pastoralists (northern Kenya) to grow
forests—food forests
F u l l
a r t i c l e
a t
l i n k ,
https://www.takepart.com/article/2015/08/25/pastoralistsdrought-food-forests
Some extract:
In drought-ravaged Samburu County, 80 percent of the
population lives below the poverty line. But it's on this semiarid
landscape that Aviram Rozin, founder of Sadhana Forest is
training Samburu pastoralists to grow forests—food forests.
Designed to emulate the layered ecology of a natural forest, a
food forest is made of seven layers hat range from tall trees to
short shrubs, each working in support of the others. In
Samburu County, these forests are planted with 18 species of
drought-resistant, fruit-bearing indigenous trees and shrubs,
including African oak, the fruits of which are said to be rich in
protein and iron, and moringa,known locally as “mother's
helper” thanks to its fruit, which helps stimulate milk
production in lactating mothers and reduces malnutrition
among infants. Sadhana Forest has trained more than 1,000
people in this low-tech approach to agriculture since it
launched its Kenya operation in May 2014.
As long as we value a dead tree more than a tree that's
alive we are in trouble.
Source: Paul Polman tweet @wemeanbusiness
Paul Polman @PaulPolman
[email protected]
Nature & Faune Volume 30, Issue No. 1
114
ANNOUNCEMENT
Reforestation conference Accra, Ghana
16 -17 March 2016
It's time for hands on to remove barriers and dramatically
boost reforestation
Reforestation and landscape restoration as means of
combating climate change are now high on the agenda of
many governments and organizations, especially in the wake
of COP21 in Paris. Close cooperation between businesses
and investors is needed to meet this challenge and to
develop plantation forestry into a stable and sustainable
business that will be beneficial to all involved. The
opportunities for all stakeholders are huge. A number of
projects are already in place, and initiatives such as AFR100
are demonstrating a strong commitment, but the pace and
scale of operations is still far too low to reverse forest loss.
The successful creation of new forests requires close, longterm commitment and cooperation between all parties. It is for
this reason that we have set up a working conference on
March 16 and 17, 2016 in Accra, Ghana. The conference is
part of the initiative 'Forests for the Future – New Forests for
Africa' which aims at large scale reforestation in Africa. As
finance is a key enabler the conference will have a strong
focus on the financial aspects of reforestation. We are proud to
announce that one of our keynote speaker will be the
Honorable Mr. Kofi Annan, Chairman of the Kofi Annan
Foundation.
The conference is on invitation only and based on the impact
attendees can and will have on reforestation in Africa. If you
believe you should be participating in the conference, please
send an e-mail with your personal details and reason for
attendance to: [email protected]
International Conference Centre, in Nairobi, Kenya from 1st to
5th February 2016. The theme selected for the Twentieth
Session and the Fourth African Forestry and Wildlife Week is
“Sustainable Management of Forests and Wildlife in Africa:
Enhancing Values, Benefits and Services”. The theme has
been purposely selected with AFWC bureau members to
highlight and implement the many facets of sustainable
management of forestry and wildlife, and to fully capture their
importance in sustaining the livelihood of millions of people,
and in contributing, in general, to sustainable development in
the region. The AFWW will be held simultaneously with the
Commission Session. Its purpose is to further draw the
attention of policy makers and the public to the contribution of
forests and wildlife to the national economy and the
improvement of the livelihoods of the populations and,
therefore, the need to give better recognition to forestry and
wildlife in the broader national development agenda. The
Week will include several exhibitions and side events.
International compost awareness week
1-7 May 2016
International Compost Awareness Week (ICAW) is the largest
and most comprehensive education initiative of the compost
industry. It is celebrated each year in the first full week of May.
For more details follow the link:
http://compostingcouncil.org/icaw/
FAO launches series of educational materials
on the role of healthy soils
For more information (program, etc.) visit:
http://newforestsforafrica.org
Twentieth Session of the African forestry and
wildlife commission, Nairobi, Kenya.
1 - 5 February 2016
At the kind invitation of the Government of the Republic of
Kenya, the Twentieth Session of the African Forestry and
Wildlife Commission (AFWC) and the Fourth African Forest
and Wildlife Week (AFWW) will be held at the Kenyatta
A new series of educational materials is teaching children the
importance of healthy soils for our food, environment,
livelihoods and well-being.
Nature & Faune Volume 30, Issue No. 1
115
Educational Material
Learn more about soils through our educational booklets for
children ages 5 to 14. An educator's guide is also available for
teachers.
DIG IT! The Secrets of Soil
Advanced
DIG IT! The Secrets of Soil
Beginner
DIG IT! The Secrets of Soil
Intermediate
DIG IT! The Secrets of Soil
TXT MSG FRM UNDR UR FT
Nature & Faune Volume 30, Issue No. 1
116
THEME AND DEADLINE FOR NEXT ISSUE
The next edition of Nature & Faune journal will feature short
articles linked to the theme of “Sustainable management of
forests and wildlife in Africa: enhancing values, benefits and
services”. This is consistent with the journal's mission to
profiling the natural resource management and its
contribution to sustaining livelihoods of people across Africa.
This edition of Nature & Faune journal is one of the
contributions of Food and Agriculture Organization of the
United Nations to highlight the multi-facets of sustainable
management of forestry and wildlife, and to fully capture their
importance in sustaining the livelihood of millions of people
and in contributing, in general, to sustainable development in
the region.
As the world's forests continue to shrink as populations
increase and forest land is converted to agriculture and other
uses, the rate of net global deforestation has slowed down by
more than 50 percent for the past 25 years. The good news is
that increasing amount of forest areas have come under
protection while more countries are improving forest
management. This is often done through legislation and
includes the measuring and monitoring of forest resources
and a greater involvement of local communities in planning
1
and in developing policies .
The year 2015 was critical and led to a new development era
with the adoption of the 2030 Agenda for sustainable
development. The post-2015 development agenda
reaffirmed the importance of forest through its Goal 15:
“Sustainably manage forests, combat desertification, halt and
reverse land degradation, halt biodiversity loss”. In September
2015, the XIV World Forestry Congress (WFC) produced the
Durban Declaration2. The Congress offered a new vision for
forests and forestry where (i) Forests are more than trees and
are fundamental for food security and improved livelihoods.
(ii) Integrated approaches to land use provide a way forward
for improving policies and practices (iii) and Forests are an
essential solution to climate change adaptation and
mitigation.
Africa has achieved a momentum and reminded the Congress
participants about the start of a journey towards “Africa 2063
3
Agenda” and further urged Africans to translate the principles
4
of “the Africa we want” into concrete and actionable
programmes in the forestry and natural resource
management sectors. It further called for multisectorial
integrated approaches of sustainable management of forest
resources, technological innovations and strengthening in
the forestry sector and for further investment and financing.
A new milestone has been set with the Paris Agreement,
adopted during the Cop21 of the United Nations Framework
Convention on Climate Change (UNFCCC) last December
2015. The recently concluded COP21 of the UNFCCC, further
recognized the role of conservation, sustainable
management of forests and enhancement of forest carbon
stocks; as well as alternative policy approaches, such as joint
mitigation and adaptation approaches for the integral and
sustainable management of forests; while reaffirming the
importance of non-carbon benefits associated with such
approaches; encouraging the coordination of support from,
inter alia, public and private, bilateral and multilateral sources.
To further measure and enhance the importance of forests, we
need to improve our understanding of the people who live in
and around forests, what kind of values, benefits and services
do they get to sustain their livelihoods, and what kind of
policies and regulations influence these interactions. The
editorial board is therefore inviting authors to submit articles
that address the broad contributions of forests, trees, wildlife
and naturals resources in general on topics such as value
addition of wood and non-wood forest products; forests and
wildlife for social and economic development; forest and
water resource management; forestry and climate change
adaptation and mitigation; illegal hunting and trade; forest and
wildlife policies; and forest and landscape restoration in Africa.
Deadline for submitting manuscripts for the next issue
is 30 April 2016.
1
http://www.fao.org/forest-resources-assessment/en/
2
http://www.fao.org/about/meetings/world-forestrycongress/outcome/en/
3
Africa 2063 Agenda is "A global strategy to optimize use of
Africa's resources for the benefits of all Africans"
4
The Africa We Want”. It reflects a vision for Africa based on
aspirations of African countries and their people,
articulated in “Agenda 2063 – the Future We Want for Africa” as
an “integrated, people-centered, prosperous Africa, at peace
with itself”. The Agenda 2063 also enhances the ideals of PanAfricanism. Visit: http://agenda2063.au.int/
Nature & Faune Volume 30, Issue No. 1
117
GUIDELINES FOR AUTHORS,
SUBSCRIPTION AND CORRESPONDENCE
For our subscribers, readers and contributors:
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Nature & Faune Volume 30, Issue No. 1
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Nature & Faune Volume 30, Issue No. 1
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Nature & Faune journal is a peer-reviewed open access international bilingual
(English and French) publication dedicated to the exchange of information
and practical experience in the field of wildlife and protected areas
management and conservation of natural resources on the African continent.
It has been in wide circulation since 1985. Nature & Faune journal is
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o
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