Soil and Agricultural Land Assessment Study

Table of Contents
Introduction .................................................................................................................................... 1
Planning Overview........................................................................................................................... 2
Agricultural Land Classification (ALC) .............................................................................................. 6
Agricultural Land Quality – West Sussex Coastal Plain ................................................................. 11
Agricultural Land Quality – Arun District....................................................................................... 15
Agricultural Land Quality – Strategic Development Sites ............................................................. 19
Impact and Mitigation Measures .................................................................................................. 40
Food Production and Security ....................................................................................................... 42
Green Infrastructure Study ........................................................................................................... 43
10. Limitations to the Study ................................................................................................................ 44
11. The Future ..................................................................................................................................... 45
12. Summary ....................................................................................................................................... 48
Glossary ................................................................................................................................................. 50
Appendix 1: Methodology for assessing land gross margins ................................................................ 51
Arun District covers an area of approximately 22,100 hectares in West Sussex, including
three main urban centres; Bognor Regis, Littlehampton and Arundel; and the South Downs
National Park. Arun is the most populous district of West Sussex, currently with just under
150,000 residents, a figure which is expected to rise by 26,000 by 2030 1.
If the population is to expand in line with predictions, there is a clear need for
simultaneous improvements to the employment sector, which is already lagging, and social
infrastructure. It is now crucial for strategic level planning for the future of Arun to
While there is a clearly identified local need for housing and employment sector growth in
the Arun District, the emerging dilemma is identifying the most appropriate areas for such
Much of the agricultural land in the West Sussex Coastal Plain is classified as “best and
most versatile” quality, which is considered to be the most productive land and which is
offered protection from development by national planning policy. When compared with
the average proportions of land of differing quality across England, Arun District has a
relatively high proportion of best and most versatile land.
However, the benefits of agricultural land are greater than food production alone, hence
decisions to use or protect agricultural land, whether categorised as best and most
versatile quality or not, are not necessarily simple. There are a range of interlinking factors
that influence the sensitivity of land, and methods which can potentially be implemented
to reduce this sensitivity and the subsequent impact of its loss.
The aims of this study are therefore to:
identify the distribution of best and most versatile quality agricultural land in Arun;
Evaluate the distribution of land quality at four sites identified for strategic housing
Assess the likely economic, food security and sustainability implications of the
potential loss of land at each site to development; and
Office of National Statistics (ONS), Subnational Population Projections, Local Authority Profiles: Demography Report,
updated 16/01/2013.
Use the findings to inform a comprehensive planning policy which best addresses the
balance between the need for growth and the need to protect the most valuable
agricultural land.
Planning Overview
Innovating for Sustainable Growth: A Bioeconomy for Europe (2012)
This strategic document recognises that in order to cope with the pressures of population
growth, rapid resource depletion, increasing environmental pressures and climate change,
Europe needs to radically change its approach to production, consumption, processing,
storage, recycling and disposal of biological resources. The purpose of the Strategy is to;
‘pave the way to a more innovative, resource efficient and competitive society that
reconciles food security with the sustainable use of renewable resources for industrial
purposes, while ensuring environmental protection.’
The approach to be taken will develop an extensive knowledge base, encompassing
information sources from cutting edge scientific research to tacit “on the ground”
knowledge. The information will be utilised to sustainably increase primary production for
both consumption and bioenergy, reduce demand on non-renewable energy resources,
increase the efficiency of the food processing industry and supply chains, and encourage
further development and investment in the bioeconomy sector.
National Planning Policy
The National Planning Policy Framework (NPPF), effective as of March 2012, sets out the
Government’s policies for sustainable development in England. The concept of sustainable
development recognises that growth and development are necessary, but that resources
for future generations should not be jeopardised for the benefit of the present generation.
Sustainable development is based upon three elements as defined in the NPPF:
“an economic role – contributing to building a strong, responsive and competitive
economy, by ensuring that sufficient land of the right type is available in the right
places and at the right time to support growth and innovation; and by identifying
a social role – supporting strong, vibrant and healthy communities, by providing the
supply of housing required to meet the needs of present and future generations; and
by creating a high quality built environment, with accessible local services that reflect
the community’s needs and support its health, social and cultural well-being; and
an environmental role – contributing to protecting and enhancing our natural, built
and historic environment; and, as part of this, helping to improve biodiversity, use
natural resources prudently, minimise waste and pollution, and mitigate and adapt
to climate change including moving to a low carbon economy.”
These elements should not be considered individually, but collectively, to ensure that an
holistic approach is taken to development to produce the most sustainable outcome.
Furthermore, there are 12 core land-use principles which underpin the presumption
toward sustainable development. Broadly speaking, these are that the planning system
empower local people to shape their surroundings;
seek to enhance and improve the places in which people live their lives;
identify and meet housing, business and other development needs of an area;
secure high quality design of land and buildings;
take account of the different roles and characters of different areas;
support the transition to a low carbon future;
conserve and enhance the natural environment;
encourage the re-use of previously developed land;
promote mixed use developments and recognise that open land performs many
conserve heritage assets;
actively manage patterns of growth to ensure the best possible use of public
transport, and walking and cycle routes; and
aim to improve health, social and cultural wellbeing.
The NPPF is intended to constitute the basis from which Local Plans are made. Local Plans
should favour development which is sustainable and should provide guidance as to how
this can best be achieved within a specific local context. It is stated within the NPPF that
development proposals which are in accordance with the relevant Local Plan should be
approved, and those which contradict the Local Plan shall be refused. It is therefore of
great importance that Local Plans are up-to-date and that they comprehensively
encompass all three pillars of sustainability.
The NPPF and Agriculture
Paragraph 109 of the NPPF states that:
‘The planning system should contribute to and enhance the natural and local environment
protecting and enhancing valued landscapes, geological conservation interests and
recognising the wider benefits of ecosystem services;
minimising the impacts on biodiversity and providing net gains in biodiversity where
possible, contributing to the Government’s commitment to halt the overall decline in
biodiversity, including by establishing coherent ecological networks that are more
resilient to current and future pressures;
preventing both new and existing development from contributing to or being put at
unacceptable risk from, or being adversely affected by unacceptable levels of soil, air,
water or noise pollution or land instability; and
remediating and mitigating despoiled, degraded, derelict, contaminated and unstable
land, where appropriate.’
Paragraph 112 goes on to advise that ‘local planning authorities should take into account
the economic and other benefits of the best and most versatile agricultural land’ when
making decisions on development, and that ‘where significant development of agricultural
land is demonstrated to be necessary, local planning authorities should seek to use areas
of poorer quality land in preference to that of a higher quality’.
For the purposes of agricultural land quality assessment, “best and most versatile quality”
land is that assessed as being of Grade 1, 2 or 3a, whilst poorer quality land is that of
Grades 3b, 4 and 5. Assessment is made according to the Ministry of Agriculture, Fisheries
and Food (MAFF) revised guidelines and criteria for grading the quality of agricultural land
Local Planning Policy
Arun Core Strategy Options for Growth Consultation 2009
The Arun Core Strategy Options for Growth Consultation 2009 document identified
objectives and policies for large, strategic residential, business and infrastructure
Three preferred options for growth were identified in the document:
Sustainable urban extensions to the towns of Bognor Regis and Littlehampton;
Development of an eco-town at Ford (SHLAA Site 71); and
Sustainable urban extension at Littlehampton, in addition to significant development
around the three villages of Eastergate, Westergate and Barnham, and in the Parish of
The sites identified in the Core Strategy Consultation document remain of high interest for
sustainable development options in Arun, and hence are evaluated in the main body of this
Arun’s Draft Local Plan 2012
The development aims for Arun are best summed up in Paragraph 7.6 of the Draft Local
Plan 2012:
“For Arun to remain sustainable into the future it will need to ensure that developments will
make a positive contribution towards ensuring that there is high quality, affordable housing
with excellent social infrastructure; there is a diverse and thriving economic base that
improves the vibrancy of the town centres; there is efficient and sustainable movement
within and beyond Arun and that it both enhances its environmental integrity and
maximises natural resource efficiency”
While there is an emphasis on the economic and social advantages of development,
inclusion of environmental integrity and natural resource efficiency ensures that all three
pillars of sustainability are addressed.
Arun’s Wider Context
Arun cannot be considered as a closed system, but rather as a wider unit encompassing
neighbouring districts, in particular Chichester. Arun District Council produced an Economy
and Employment context paper, used as a supporting document for a report by the EcoTowns Select Committee. Within the paper, Arun is described as:
“a daily exporter of labour, with almost three times the number of people commuting out,
rather than into, the District for employment.
A significant proportion of this out-
commuting is into neighbouring districts”.
Arun is tightly linked with Chichester, not only in terms of the local workforce, but also of
waste management and water resources, and hence any significant development schemes
must account for the potential for cross-boundary impacts.
Agricultural Land Classification (ALC)
The quality of agricultural land is assessed according to the MAFF revised ALC guidelines.
The ALC system provides the framework for classifying land in England and Wales
according to the extent to which physical and chemical factors interact to impose long
term limitations on the agricultural use of the land. The limitations may affect:
the range of crops which can be grown;
the achievable yields;
the consistency of crop yields; and
the cost of obtaining the crop yield.
The principal physical factors influencing agricultural production are climate, site and soil.
These factors together with interactions between them form the basis for classifying land
into one of five grades; Grade 1 land being of excellent quality and Grade 5 land of very
poor quality. Grade 3, which constitutes about half of the agricultural land in England and
Wales, is now divided into two subgrades designated 3a and 3b.
The grade or subgrade of land is determined by the most limiting factor present. When
classifying land the overall climate and site limitations should be considered first as these
can have an overriding influence on the grade. A summary of the ALC grades in terms of
the type of limitation which can occur is given in Table 1.
The agri-climatic factors considered are: average annual rainfall, accumulated
temperatures, field capacity days and moisture deficits. These data are derived from the
Meteorological Office's (1989) standard 5km grid point data set.
The average annual rainfall is measured in mm per year and in combination with localised
soil types and textures, affects for how long and to what extent a site may be waterlogged
in any given year, which in turn can impact on when heavy machinery may be used on the
Accumulated temperature refers to how many degrees above 0°C accumulate between
January and June. This indicates the heat energy input and soil drying capacity for a site,
which directly affect crop growth.
The number of Field Capacity Days indicates the number of days during which the soil
moisture deficit is zero. This state is achieved when excess water has drained from a soil
profile, typically two to three days following rainfall, and the soil pores contain both air and
water. The average number of days during which soil in lowland England is at Field
Capacity is 150, and this is considered to be favourable for providing opportunities for land
working. Fewer than average Field Capacity Days is considered increasingly favourable,
whilst longer regimes are less favourable for land working.
Soil moisture deficit is a variable which represents the balance between rainfall and
potential evapotranspiration. These values are used in ALC assessments to determine the
potential for two reference crops, wheat and potatoes, in a given soil to suffer from the
effects of droughtiness.
The site factors which are generally considered include aspect, gradient, microrelief and
flood risk. As well as affecting climatic parameters, these factors impact on the ease and
safety of machinery usage, as well as potential for harm to livestock and crops.
Finally, the soil characteristics affecting the ALC grading include the texture (which in turn
affect soil stability, moisture retention and drainage), depth of each soil horizon and the
stone content (which affects water holding capacity and the rate of wear on farm
The physical limitations which result from interactions between climate, site and soil are
soil wetness, droughtiness and susceptibility to erosion. Each soil can be allocated a
Wetness Class (WC) based on soil structure, evidence of waterlogging and the number of
Field Capacity Days; the topsoil texture then determines its ALC Grade. A poor soil
structure can create a slowly permeable layer within the soil profile which impedes
drainage. If the depth to the slowly permeable layer is shallow, excess rain- or floodwater
will be unable to drain away easily and waterlogging is more likely to occur. The depth to
this layer is therefore of importance, with a greater depth allowing better drainage. Well
draining soils have a high WC, e.g. WC I, while poorly draining soils have a lower WC, such
as WC IV.
Droughtiness is determined by comparing the available water capacity of the soil, with the
moisture deficit for the locality for two reference crops, winter wheat and potatoes. The
moisture deficit represents the balance between rainfall and evapotranspiration in a
locality. Subtracting the moisture deficit from the amount of water available in a soil gives
the moisture balance in mm. A more negative moisture balance results in a greater
restriction to the ALC grading of the land, for example a moisture balance for wheat of 50mm will restrict land to Subgrade 3b, while one of +30mm will be of Grade 1.
The agricultural land quality of England has been mapped provisionally, on a strategic scale
of 1:250,000. The national dataset is derived from a series of regional maps which were
originally based on reconnaissance surveys and published in 1977. As the maps were
created prior to the subdivision of Grade 3, which now has important policy implications,
they can be used only for general guidance and not for the assessment of individual land
parcels. The distribution of Provisional ALC grades across England is shown in Figure 1, and
the proportions are given in Table 2.
Table 1: Description of ALC grades
Land with no or very minor limitations to agricultural use. A very wide
Grade 1
range of agricultural and horticultural crops can be grown and commonly
includes top fruit, soft fruit, salad crops and winter harvested vegetables.
Yields are high and less variable than on land of lower quality.
Land with minor limitations which affect crop yield, cultivations or
harvesting. A wide range of agricultural and horticultural crops can
Grade 2
Very good
usually be grown but on some land in the grade there may be reduced
flexibility due to difficulties with the production of the more demanding
crops such as winter harvested vegetables and arable root crops. The
level of yield is generally high but may be lower or more variable than
Grade 1.
Land capable of consistently producing moderate to high yields of a
narrow range of arable crops, especially cereals, or moderate yields of a
wide range of crops including cereals, grass, oilseed rape, potatoes, sugar
beet and the less demanding horticultural crops.
Land capable of producing moderate yields of a narrow range of crops,
principally cereals and grass or lower yields of a wider range of crops or
high yields of grass which can be grazed or harvested over most of the
Land with severe limitations which significantly restrict the range of crops
and/or level of yields. It is mainly suited to grass with occasional arable
Grade 4
crops (e.g. cereals and forage crops) the yields of which are variable. In
moist climates, yields of grass may be moderate to high but there may be
difficulties in utilisation. The grade also includes very droughty arable
Grade 5
Very poor
Land with very severe limitations which restrict use to permanent pasture
or rough grazing, except for occasional pioneer forage crops.
Figure 1: Provisional ALC data for England (Defra, 2009)
Table 2: Estimated areas of each agricultural land quality grade in England
Grade 1
Grade 2
Grade 3
Grade 4
Grade 5
Agricultural Land Quality – West Sussex Coastal Plain
The West Sussex Coastal Plain extends from the fringes of Portsmouth in the west, to the
valley of the Adur to the east. The plain is split into five areas according to landscape
characteristics: the Lower Coastal Plain; the Upper Coastal Plain; the South Downs; the
Eocene Outcrops; and the Alluvial Valleys, shown in Figure 2.
Figure 2: Landscape characteristics of the West Sussex Coastal Plain (Harpenden, 1967)
These five character areas can be further distinguished by the broad associations of soil
types present in them, shown in Figure 3. The Lower Coastal Plain is dominated in the
west by naturally wet, loamy and clayey soils, which become freely draining to the north
and east. The Upper Coastal Plain is comprised of loamy soils which have naturally high
groundwater, but which become freely draining to the north.
The South Downs section is dominated by shallow, freely draining, lime rich soils.
Eocene Outcrops are associated with soils which are generally slowly permeable and
seasonally waterlogged, with loamy and clayey textures.
Finally, soils of the Alluvial Valleys are loamy and clayey in texture and, as expected, have
naturally high groundwater, which means they are wet
Figure 3: Broad soil types of the West Sussex Coastal Plain, according to general
characteristics (Cranfield University (NSRI), 2013)
The differing soil types mapped across the coastal plain, and their associated properties
(for example, drainage status and texture) are reflected in the provisional maps of
agricultural land quality (Figure 4). A significant proportion of land in the Lower Coastal
Plain is mapped as Grade 1 and is in association with the freely draining, slightly acidic soil
types mapped.
As the soils become wetter toward the coast, the land quality lowers to interspersed
Grades 2 and 3. There is some correlation between land of Grade 3 quality and the Alluvial
Valleys which traverse the section, although they are not strictly associated.
The poorest land quality of the West Sussex Coastal Plain is mapped to the north as the
land rises into the South Downs. The broad soil type is shallow and free draining which
suggests that soils suffer from droughtiness, resulting in provisional Grades of 3 and 4.
Most of the land over the Eocene Outcrops is classified as non-agricultural, being almost
entirely under woodland or scrub. Where pockets of agricultural land are mapped, they
are mostly of Grade 3.
Regional soil associations, provisional ALC map data, climatic data and published soil survey
information have been analysed together by Defra for the purpose of producing maps of
the “Likelihood of best and most versatile land”. These are strategic scale maps which
indicate where there is a high, moderate or low likelihood of the occurrence of best and
most versatile land. The high likelihood category refers to areas where more than 60% of
land is likely to be best and most versatile, the moderate likelihood category areas where
20 to 60% of the land is likely to be of best and most versatile quality, and the low
likelihood category indicates where less than 20% of land is likely to be of best and most
versatile quality. Mapping of the likelihood of best and most versatile land for the Arun
District is shown in Figure 5.
Land provisionally mapped as being of Grades 1 and 2 has automatically been placed in the
high likelihood category, and land with an overall climatic limitation automatically placed in
the low likelihood category.
Figure 4: Provisional ALC mapping of the West Sussex Coastal Plain (MAFF 1970)
Agricultural Land Quality – Arun District
The Arun District covers much of the east of the West Sussex Coastal Plain and
encompasses land provisionally mapped as Grades 1 to 4, as well as non-agricultural land.
The highest quality land is generally in the south west of the district, to the north of Bognor
Regis. The Grade 1 and 2 quality land areas are largely consistent with soils of the Hook
series, which develop in silty drift and may occasionally suffer from impeded drainage, but
are mostly well-drained.
The poorest quality agricultural land is mapped on the South Downs where the Icknield and
Coombe series are mapped. These soils are typically shallow with extremely calcareous,
silty clay loam topsoils. The main difference between the series is that Chalk bedrock is
typically reached within around 30cm of the soil surface across the Icknield series, which
also has much higher organic matter content than the slightly deeper Coombe series.
These factors are likely to culminate in a severe droughtiness limitation to Grades 4 and 3b,
although there is no detailed ALC data available to compare with this strategic data. In
addition to the shallow soils, land quality over the South Downs may also be restricted in
some places by gradient.
Figure 5: Likelihood of Best and Most Versatile Land in Arun District (Defra, 2002). This map is a crude visual indicator of likely
agricultural land quality: it is not a definitive data source and cannot be used to assess individual sites
The remainder of land provisionally mapped as being of Subgrade 3b quality tends to occur
in areas in which Park Gate soils are mapped. These soils are clayey or loamy in texture
and are typically seasonally waterlogged.
Agricultural Productivity – Arun, Adur and Worthing Districts
The latest Defra statistics (2010) on agricultural land use in Arun are combined with those
from the neighbouring districts of Adur and Worthing. In 2010, the total farmed area
across the three districts was 13,738 hectares, which included:
4,300ha cereal crops;
1,939ha other arable crops (excluding cereals);
331ha of fruit and vegetables; and
5,938ha grassland.
The distribution of four crop types across Arun District (outlined in blue) in 2010 are
represented in Figure 6, and can be seen in the context of West Sussex (outlined in red)
and the wider south east England region.
From these figures, it can be seen that cereal and oilseed rape crops do not make up as
substantial a contribution to the overall agricultural output of Arun district, as they do in
other areas of West Sussex and the south east. The difference may be attributed to the
potential for the relatively high quality land of Arun District to produce good yields of
higher value fruit and vegetable crops.
The productivity of crops in terms of economics across the Strategic Development Sites
been estimated using crop statistics for West Sussex, obtained from Defra and standard
gross margins for 2013 to produce an average annual gross margin (AAGM), expressed in
terms of per unit area and across the whole site. The full methodology for assessing the
AAGM of one hectare of land is given in Appendix 1. For the purpose of this assessment, it
is assumed that land of Grades 1 and 2 will consistently produce high crop yields, and that
land of Subgrades 3a and 3b will produce average crop yields. It is also assumed that fruit
and vegetable crops are grown only on high quality land.
Figure 6: Distribution of four key crops across Arun, West Sussex and the South East, 2010 (Defra, 2011)
Agricultural Land Quality – Strategic Development Sites
Figure 7 shows the provisional agricultural land quality mapped across the four strategic
development sites of, from west to east, the Bognor Regis Eco-Quarter (BREQ), the Three
Villages, the Ford Site and the Parish of Angmering.
Figure 7: Provisional ALC of four Strategic Development sites in Arun District (MAFF,
1970) Scale 1:100,000 at A4
Each section includes a series of maps from which an estimation of the distribution of land
quality throughout each site is made. The series start with a comparison between the
provisional ALC mapping, as above, and any detailed post-1988 ALC data available. As
stated in Paragraph 3.13, the provisional ALC is based on strategic data, which means that
large scale trends rather than detailed survey findings were mapped. Comparison with the
results from detailed surveys which have been undertaken according to the most up to
date guidance reveals any strengths or weaknesses in the correlation and therefore in the
accuracy of the provisional data.
The detailed ALC findings are then compared with the soil series’ mapped at the site. Soil
series mapping was based on observations of soil profiles in road cuttings, auger borings
and pits; site vegetation; geology; and land form. Due to the level of detail involved in
each assessment, much higher correlation is expected between detailed ALC grades and
the soil series mapped, which can then be used to form the basis of the site land quality
Bognor Regis Eco-Quarter (BREQ)
Site Context
The Bognor Regis Eco Quarter (BREQ) Site (SHLAA site 125) is on the north western
boundary of Bognor Regis.
The Site covers approximately 134ha of flat, low lying
agricultural land, and is largely contained by existing infrastructure.
There are several ditches in the north of the Site which connect to the Aldingbourne Rife
approximately 1km to the east.
Climatic data have been interpolated from the Meteorological Office’s standard 5km grid
point data set (Meteorological Office, 1989). Climate at the BREQ Site is warm and
moderately moist. The number of Field Capacity Days is about average for lowland
England and is favourable for providing opportunities for land working. Moisture deficits
are large indicating that soils of some types may be slightly more susceptible to
Table 3: Local climatic factors for the BREQ
BREQ North
BREQ South
Accumulated Temperature >0°C
1545 day°
1545 day°
Field Capacity Day Regime
151 days
152 days
Average Moisture Deficit, wheat
Average Moisture Deficit, potatoes
Average Annual Rainfall
Geology and Soil
There are two geological units underlying the BREQ Site. To the south, the bedrock is clay
and to the north, the bedrock is chalk.
The differing geology gives rise to soils possessing different properties. To the south of the
survey area overlying the clay are soils of the Park Gate series, which are seasonally
waterlogged, silty clay loam profiles.
Overlying the chalk bedrock to the north, and making some intrusions into the BREQ site
from the east, are soils of the Hook series, which have very similar characteristics to the
Park Gate soils, but which are only occasionally waterlogged.
Land Use
The assessment of land use has been estimated from aerial photography of the Site taken
in June 2012. Various fruit and vegetable crops are grown in the northernmost 36ha of the
Site, and the balance is under grass and cereals.
The areas and proportions of each crop area are given below in Table 4, alongside the
areas across the districts of Arun, Adur and Worthing (combined data for 2010) for
comparison. Of particular note is the high proportion of land used for growing fruit and
vegetables compared with the proportion across the three districts.
Table 4: Agricultural Land Use, BREQ
Arun, Adur and Worthing
Area (ha)
Area (%)
Area (ha)
Area (%)
Total Farmed
Arable, Cereals
Arable, excl.
Fruit and
Land Quality
Provisional ALC mapping of the Site shows it to comprise a majority of Grade 2 land, with a
small portion of Grade 1, excellent quality land, in the north east.
The “Likelihood of Best and Most Versatile Land” map for West Sussex shows that over
60% of land at the BREQ Site would be expected to be of best and most versatile quality.
Detailed post-1988 ALC surveys have been undertaken at two locations within the Site.
The largest surveyed parcel of around 30ha is in the south over the clay geology and wet
Park Gate soils. Land was assessed mostly as Subgrade 3a quality, with around 6.5ha of
Subgrade 3b quality land. This corresponds with the location of the wheat crop.
The second surveyed area forms a strip of around 6.5ha to the north of the study area
where the chalk geology and better draining soils are mapped. The area is assessed as
being of Grades 1 and 2, and corresponds with the areas of horticultural and row crops.
The total areas of the different ALC grades derived from detailed surveys, as well as
regional and national averages, are given below in Table 5.
Table 5: Detailed Agricultural Land Classification data for the BREQ Site
Area (ha)
% of Detailed
National Average (%)
Arun District
Average (%)
It can be seen in Figure 8 that the provisional ALC mapping (8a) and the detailed ALC
survey results (8b) are not highly consistent. However, there is good correlation between
the detailed ALC mapping and the soil series mapping (c) and as such, the boundary
between the soil and geology types is considered likely to represent the approximate
boundary between the highest quality land of Grades 1 and 2 in the north of the Site, and
lower quality land of Subgrades 3a and 3b in the balance of the area. Extrapolation of this
data across the BREQ site has enabled an estimation of the likely distribution of land
quality to made, as shown in the fourth frame (d).
The BREQ site is likely to constitute a majority of best and most versatile quality land, with
pockets of Subgrade 3b quality land also present.
Figure 8: (a) Provisional ALC map data (b) Detailed ALC survey data (c) Soil series mapping
23 and (d) Estimation of land quality distribution
Economic Productivity
Based on the predicted land quality distribution, it is estimated that around 36ha is high
yielding land. The AAGM of one hectare of high yielding land has been calculated at £750,
and therefore the AAGM at the BREQ site is in the region of £27,000.
The remaining 98ha of the agricultural land of Subgrades 3a and 3b is considered to be
capable of producing average crop yields.
One hectare of average yields of crops,
excluding fruit and vegetables, has an AAGM of around £490 per year. The AAGM of these
crops on 98ha at the BREQ site is therefore estimated at around £48,000.
In total, agriculture at the BREQ site is estimated to have an AAGM of around £75,000 per
Impact of Development
Most of the site is predicted to be of best and most versatile quality, with the exception of
some Subgrade 3b quality land. In the national planning context, loss of Subgrade 3b land
is not considered to be of as high significance as loss of best and most versatile land.
Therefore, national planning policy states that Subgrade 3b should be used in preference of
Grades 1, 2 and 3a.
The loss of the two northernmost fields would have the most significant impact in terms of
loss of agricultural land and economic productivity, as they are of Grade 1 and 2 quality
and have the most potential to support high value horticultural and field crops. As much of
the remainder of the area is also of best and most versatile quality of Subgrade 3a, the
resulting impact of development of the BREQ site is likely to be considered a major
negative effect.
Barnham, Eastergate and Westergate (Three Villages)
Site Context
The Site is approximately 3km north of Bognor Regis and is largely enclosed by an arc
formed by the villages of Barnham, Eastergate and Westergate. The Site is dissected from
east to west by a railway line and in total is estimated at around 160ha.
The Site is generally warm and moist, but the number of Field Capacity Days is slightly
larger than the national average and is considered to be slightly unfavourable for providing
opportunities for land working. This has an overriding impact on land grading when used
to assess the quality according to the ALC guidelines.
Table6: Local climatic factors, Three Villages
Three Villages, East
Three Villages, West
Accumulated Temperature >0°C
1537 day°
1537 day°
Field Capacity Day Regime
158 days
157 days
Average Moisture Deficit, wheat
Average Moisture Deficit, potatoes
Average Annual Rainfall
Geology and Soil
The Three Villages study area sits predominantly over London Clay geology which, around
the northern outskirts of the site, is overlain by superficial river terrace deposits of sand,
silt and clay.
The Park Gate soil series occupies a majority of the site and comprises silty clay loam soils
which are typically moderately permeable and hence are susceptible to seasonal
waterlogging. Along the northern perimeter of the area, the Hook soil series is mapped.
This is similar to the Park Gate series but is slightly better draining.
Water channels adjoining the Lidsey Rife flow around the eastern and western perimeter
of the Three Villages Site, and bring with them a range of soils of the Calcetto, Wickham
(previously Titchfield), Lyminster and Gade series.
Calcetto soils are loamy and often sandy but are imperfectly drained and seasonally
waterlogged. The Wickham series comprises fine loamy and clayey soil textures and are
seasonally waterlogged. Soils of the Gade Complex are developed in deep freshwater
alluvium to the west of the Site, and comprise moderately- to poorly drained, silty textured
A small area of the Lyminster series is mapped. Lyminster series soils are typically sandy
and well drained.
Land Use
Land in the Three Villages study area is agricultural, comprising around two thirds arable
and the remainder under grass. Aerial photography shows rotations on the arable land to
include cereals and oilseed rape.
Land Quality
Provisional ALC mapping for the Three Villages Site shows the area to be of Grade 2, good
quality agricultural land. The “Likelihood of Best and Most Versatile Land” map for West
Sussex (Figure 5) shows the whole of the Site to be within an area where over 60% of the
land is expected to be of best and most versatile quality.
Detailed ALC surveys have been undertaken around the northern perimeter of the Site,
totalling almost 50ha. This data shows approximately 75% of the land to be of best and
most versatile quality and 25% of Subgrade 3b quality, with a noticeably large proportion
of Grade 2 quality land compared with the average across the district and the nation. The
areas of each grade derived from the detailed ALC data available are given in Table 7,
alongside regional and national averages.
Table 7: Detailed ALC data for the Three Villages area
Area (ha)
% of Detailed
National Average (%)
Arun District
Average (%)
Detailed survey of the western side of the Three Villages site covers an area in which the
most soil series are mapped. The areas of Grade 2 quality land are consistent with soils of
the Hook series. The limitations to Subgrade 3a and 3b were either due to droughtiness
caused by a high local stone content, or soil wetness, a variation which reflects the
variation in soils present around the water channels.
Around the eastern side of the Site is land of Grades 2, 3a and 3b quality. Again, this
variety can be attributed to the variable soils associated with the water channels which
extend into the area from the south.
There is some correlation between the provisional ALC mapping and the detailed ALC
survey results (Figure 9 a and b). Significant differences occur in the north where a large
area of provisionally mapped Grade 1 land was not recorded in the detailed survey results,
but instead found to be of Grade 2. The area of provisional Grade 3 to the west was also
found in the detailed survey to comprise Grades 2, 3a and 3b. The pattern of the
occurrences of these grades correlates well with the differing soil series associated with
the water courses and as such, the estimation of the distribution of land quality across the
Three Villages site area has been based on the mapped soil series (Figure 9 c and d).
The result is that most of the site is anticipated to comprise best and most versatile
agricultural land of Grades 2 and 3a, with Subgrade 3b expected where the water courses
intrude into the site.
Figure 9: a) Provisional ALC data, b) Detailed ALC survey mapping, c) Soil series mapping, d) Predicted land quality distribution
Economic Productivity
For the purpose of this study, it is assumed that land of Grades 1 and 2 will enable crops to
produce high yields, and land of Subgrades 3a and 3b will produce average yields. It has
been estimated that the Three Villages site will contain approximately 32ha of Grade 2
land, and the remaining 128ha of Subgrades 3a and 3b.
The calculated AAGM of highly productive land is £750 per hectare, which equates to a
potential AAGM of around £24,000 for the Grade 2 quality land.
The estimated value of land producing average yields is £490 per hectare. Given that there
are around 128ha of such land, the potential productivity expressed as an AAGM equates
to around £62,700.
In total, the agricultural land at the Three Villages site is anticipated to have an AAGM of
£86,700 per year.
Impact of Development
Loss of the land around the northern periphery of the Three Villages site would have the
greatest impact in terms of loss of land quality, economic productivity, and social factors,
such as the visual impact on existing settlements. The land of Subgrade 3b quality sits
within a floodplain and therefore the impact of the loss in agricultural and productivity
contexts may be less severe than the better quality land surrounding it, although it could
be more valuable in ecological and biological contexts.
Regardless of the portion of Subgrade 3b land, the amount of best and most versatile
quality land which would be lost to development at the site would be considered in
planning terms to be a permanent negative effect of major significance.
Ford Site
Site Context
The Site at Ford (SHLAA site 71) sits to the north west of Littlehampton and extends to
around 400ha in total. The Site is largely contained by suburban land uses, including the
villages of Yapton, Climping and Ford.
Within the Site is a former airfield which ceased functioning in the 1980s. It is now
predominantly agricultural, but also the location of a sewage works and the Ford Airfield
Industrial Estate which sits just outside the site boundary. The Site is dissected in the north
by a rail line and Ford Lane, which both run roughly east to west.
The climate at the Site is generally warm and moist, leading to relatively large moisture
deficits in crops. The number of Field Capacity Days at the Site is slightly above average for
lowland England. This is considered to be slightly unfavourable for providing opportunities
for working on the land.
Table 8: Local climatic factors, Ford Airfield
Ford North
Ford South
Accumulated Temperature >0°C
1536 day°
1542 day°
Field Capacity Day Regime
157 days
152 days
Average Moisture Deficit, wheat
Average Moisture Deficit, potatoes
Average Annual Rainfall
Geology and Soil
The bedrock geology at the Ford Site is chalk. In the north and north east of the Site,
superficial marine and beach deposits of sand and gravel are mapped. Across the
remainder of the Site are river terrace deposits of sand, silt and clay.
Soils of the Hook and Hamble series are over most of the Site, both of which are deep, silty
and stoneless. The difference between Hook and Hamble soils is drainage, with the former
susceptible to occasional waterlogging, whilst the latter is well drained throughout the
Extending south of the Site, areas of the silty, imperfectly drained Park Gate series are
present in association with the Ryebank Rife. Around the northern and eastern edges of
the Site are Lyminster series soils. The Lyminster series is developed in marine deposits
and as such is sandy and well drained. The final series mapped is associated with the River
Arun, which marks part of the eastern boundary to the site, comprising the more clayey
Arundel series soils which are seasonally waterlogged by groundwater.
Land Use
Most of the site is in arable agricultural use. Non-agricultural land at the Site includes a
farmstead and the Ford Lane Industrial Site along Ford Lane to the north, the sewage
works, the Ford Depot and the old airport runways.
Land Quality
Provisional ALC mapping of the Ford site (Figure 10a) shows variable land quality, from
Grade 1 over a large central portion, to Grade 4 to the east adjacent to the River Arun.
Defra’s mapping of the Likelihood of best and most versatile land in West Sussex (Figure 5)
is consistent with the provisional mapping in that it shows a high likelihood of best and
most versatile quality land over most of the Ford study area, the exception being to the
east where the likelihood is considered moderate (equating to 20 to 60% of land expected
to be best and most versatile).
Detailed post-1988 ALC data is available for three areas within the Ford Site, totalling
around 64ha, and shown in Figure 10b. The cumulative area was predominantly found to
be of Grade 2 quality, with the remainder comprising 2.5ha of Subgrade 3a quality land, as
shown in Table 9 below. As also seen in Table 9, the proportion of Grade 2 land is
significantly higher than both the regional and national average.
Table 9: Detailed ALC areas of the Ford Airfield site
National Average (%)
% of Detailed
Arun District
Average (%)
Given the climatic conditions at Ford, areas in which soil profiles are typical of the Hook
and Hamble series (shown in Figure 10c) will be assessed as Grade 1 or 2. The small
portion of Subgrade 3a quality land is mapped over the boundary between soils of the well
drained Hook series and those of the imperfectly drained Park Gate series in the south of
the Site.
Where the Park Gate soil series continues to be mapped, aerial photography
shows evidence of crop stress.
There are clear consistencies between the soil series present and the detailed ALC findings,
and hence the predicted land quality mapping (Figure 10d) is based on the soil series
Economic Productivity
Using Figure 10d, it is estimated that around half of the site area at Ford will be high
yielding, and half would produce average yields.
The Ford study area is approximately 400ha in total and therefore 200ha of high yielding
land are present. High yields have been calculated to be worth approximately £750 per
hectare, equating to an AAGM of £150,000 from the most productive areas at the Ford
Average yielding land has been calculated at a value of £490 per hectare. When multiplied
across the remaining 200ha at the site, this equates to an AAGM of approximately £98,000.
In total, agricultural productivity at the site is estimated at around £248,000 per year.
Impact of Development
The area of productive land at Ford is vast and hence the impact of development on
agriculture and land quality will understandably be major. Development will also have a
massive impact on the economic income of Arun District, with the potential loss of almost
a quarter of a million pounds per year from the Ford site alone.
Figure 10: a) Provisional ALC data, b) Detailed ALC survey mapping, c) Soil series mapping and d) Predicted land quality distribution
Parish of Angmering
Site Context
The Parish of Angmering site lies in the east of the Arun District and is dissected east to
west by the A27. The area under consideration (and hereby referred to as the site of the
Parish of Angmering) comprises the portion of the parish south of the road, where land use
is predominantly sub-urban, and which excludes the northernmost portion of the parish
which sits within the South Downs National Park. The most significant features are the
village of Angmering and two golf clubs in the south west of the parish. The study area of
the Parish of Angmering site has been estimated at around 825ha, just under half of which
is in agricultural use. Although this assessment relates to the whole Parish of Angmering
site, in reality only portions of it would be allocated for development. This assessment
therefore represents a “worst case scenario”.
The Parish of Angmering is generally warm and moist, but the number of Field Capacity
Days is greater than the national average and is considered to be slightly unfavourable for
providing opportunities for land working. Furthermore, crop moisture deficits are also
relatively large, making irrigation necessary to produce reliable, high quality crops. These
factors have an overriding impact when assessing the quality of agricultural land according
to the ALC guidelines.
Table 10: Local climatic factors for Angmering
Angmering North
Angmering South
Accumulated Temperature >0°C
1540 day°
1534 day°
Field Capacity Day Regime
158 days
157 days
Average Moisture Deficit, wheat
Average Moisture Deficit, potatoes
Average Annual Rainfall
Geology and Soil
The principal geology of the Site is Chalk, much of which is overlain by alluvial deposits of
clay, silt, sand and gravel.
There are several soil series mapped in the parish of Angmering. The predominant soil is of
the Hamble series which is deep, silty and well-drained, and covers most of the south of
the parish. The Black Ditch brings intrusions of the clayey, alluvial Arundel and loamy
marine Lyminster series soils from the west.
Most of the soils in the north of the Site belong to the Wickham, Swanmore or Park Gate
series, which are all non-calcareous, poorly draining, fine loamy and clayey soils.
A valley running southward from the hills to the north of the parish brings silty and chalky
soils of the Charity and Strettington series. These are similar to the Hamble soils of the
south, although the Strettington soils are slightly more clayey and hence they become
seasonally waterlogged.
The variation in soil properties across the parish will result in variations in land quality.
Land Use
Around 454ha of the Parish of Angmering study area are non-agricultural, and include
residential, recreational and commercial land uses. Most of the remaining land, amounting
to around 370ha, is in productive arable or horticultural use, with a significantly larger
proportion of the land dedicated to fruits and vegetables (around 90ha) when compared
with the wider district context. Approximate proportions of land under each use are given
below in Table 11. As a significant area within the Parish of Angmering study boundary is
evidently in a crop rotation comprising cereals, grass and oilseed rape, the two arable
categories have been combined in the table for this section.
Table 11: Agricultural land use in Angmering
Arun, Adur and Worthing
Area (ha)
Area (%)
Area (ha)
Area (%)
Total Farmed
Arable, Cereals
Arable, excl.
Fruit and
Land Quality
Provisional ALC mapping for the Parish of Angmering (Figure 11a) generally shows Grade 1
quality land to the south and Grade 3 to the north. Furthermore, the “Likelihood of Best
and Most Versatile Land” mapping for West Sussex (Figure 5) shows that over 60% of land
in the south of Angmering is likely to be of best and most versatile quality. In contrast, less
than 20% of land in the north of Angmering is considered likely to be of best and most
versatile quality.
Detailed ALC surveys have been undertaken across around 90ha of Angmering parish, the
results of which are consistent with the strategic data, shown in Figure 11b. To the north
and east of Angmering, land quality has been assessed mostly as Subgrade 3b quality, with
portions of Subgrade 3a and Grade 2 land also present. Land quality is seen to improve to
the south west of the village.
Around the northern perimeter of the village of Angmering, land quality is limited by soil
wetness to Subgrades 3a or 3b. The better quality 3a is associated with the Park Gate soil
series, and the slightly lower quality 3b with the wetter Wickham series. Soil series
mapping is shown in Figure 10c.
To the east of the village, the areas of Subgrade 3b land are limited by both soil wetness
and stone content. The soils possess the silty textures of the Hamble series and the flinty
drift of the Wickham series which are mapped in the east of Angmering. Where there exist
pockets of the Hamble series in amongst the wetter soils, best and most versatile quality
land of Grades 2 and 3a is found.
As well as additional land of Grades 2 to 3b, data for the south west of the Site show a
significant area of excellent quality agricultural land of Grade 1, although the surveyed area
has since become occupied by a golf course. The Grade 1 soils were typically assessed as
silt loam textured topsoils overlying medium silty clay loam subsoils, typical of the mapped
Hamble series. These characteristics result in soil which is well draining but has a relatively
high retention capacity for moisture and nutrients.
The areas of Subgrades 3a and 3b mapped in the south comprise silty clay loam or sandy
silt loam topsoils, overlying silty clay or fine sandy clay, respectively. These soils are
consistent with the route of the Black Ditch, and the characteristics of the soil series
The areas of each grade derived from the detailed ALC data available are given in Table 12.
The proportions of land of Grades 2 and 3a quality are relatively low compared with
regional and national averages, although this is more than compensated for by the
significant proportion of Grade 1 land.
Table 12: Detailed ALC areas of Angmering
Area (ha)
% of Detailed
National Average (%)
Arun District
Average (%)
Aerial photography of the Parish of Angmering shows evidence of the changing land quality
from north to south. In the northern third, where other data sources suggest soils to be
wetter and land to be of lower quality, aerial photography shows vegetation cover to be
Given the correlation between predicted and actual patterns of land quality, it is
considered likely that where the well drained, silty Hamble soils are mapped across the
large unsurveyed area to the west of the Parish of Angmering, as well as to the south east,
land will comprise mostly Grades 1 and 2. Lower quality land of Subgrades 3a and 3b is
expected in association with the network of ditches, which will bring intrusions wetter soils
into the west. Increasing amounts of land of Subgrades 3a and 3b are expected to the
north of the Parish of Angmering, starting between Decoy Pond and Arundel Road. This
predicted land quality distribution across the Parish of Angmering is shown in Figure 11d.
Figure 11: a) Provisional ALC data, b) Detailed ALC survey mapping, c) Soil series mapping and d) Predicted land quality distribution
Economic Productivity
Of the 370ha of agricultural land in the Parish of Angmering study area, approximately
40%, or 150ha, is predicted to be of Grades 1 and 2 and so has been categorised as high
yielding. High yielding land has an estimated AAGM of £750 per hectare. As such, the high
quality land of the Parish of Angmering is estimated to have an AAGM of £112,500 per
The horticultural enterprise to the east of the A280 contributes around 85ha to this high
quality land. This area alone therefore accounts for around £63,750, more than half, of the
total AAGM for the Parish of Angmering.
The remaining 60% of the site, around 220ha, is considered to be capable of producing
average crop yields. Average yielding land is estimated to generate £490 per hectare of
crops, and hence the land of Subgrades 3a and 3b in the Parish of Angmering are estimated
to have an AAGM of £107,800.
The potential total AAGM of agriculture in this study area is therefore £220,300 per year.
Impact of Development
Land is anticipated to comprise mostly best and versatile quality. The highest quality, of
Grade 1, is mapped extensively to the south west of the Parish of Angmering, which if lost
permanently to development would be a significant negative impact. However, since
having had a detailed ALC survey, this area has become occupied by a golf course, but
while currently in non-agricultural use, there remains the potential to return the land to
production. With the best quality land preserved by the golf courses, the overall impact of
development around the study area is reduced.
Loss of the south east of the study area to development would have a significant negative
impact, primarily because around 90ha of the land is planted with high value fruit and
vegetable crops. Associated with the largest area of 85ha of these high value crops are a
farm shop, tea rooms and pick-your-own opportunities which increase the importance of
the land not just for local economy, but also local food supply. Loss to development would
consequently raise a need to import fruit and vegetables from neighbouring districts,
regions or areas further afield.
Site Comparison
The statistics applicable to each Strategic Development Site are compared below in Table
13. The data shows that, taking into consideration the estimated agricultural potential of
all of the Sites, the Ford Site is likely to be the most economically productive, in terms of
both the total site area and on a per hectare basis as it contains the highest estimated
proportion of land of Grades 1 and 2. The least economically productive site on a per
hectare basis is that of the Three Villages as it is considered most likely to contain the
highest proportion of land of Subgrades 3a and 3b.
Table 13: Site comparison table
Three Villages
Total Agricultural Area
Parish of
Grade 1 and 2 Land
Grade 3a and 3b Land
Site AAGM (£)
Site AAGM (£/ha)
Impact and Mitigation Measures
The primary impacts of developments on agricultural interests arise through loss of
productive agricultural land; loss of or damage to the soil resource; and the impact on the
farm business as a whole.
Following best practice guidance can mitigate impacts of developments on the soil
resources affected quite significantly.
The “Construction Code of Practice for the
Sustainable Use of Soils on Construction Sites” 2 gives practical advice to the construction
industry with the aim of achieving good soil management at all stages of the construction
process, from the planning stages right through to the operation phase. The document
offers best practice guidance on:
Defra, 2009. Construction Code of Practice for the Sustainable Use of Soils on Construction Sites.
Identifying existing soil resources on site;
On-site soil management;
Topsoil and subsoil stripping;
Soil stockpiling and placement;
Sourcing, importing and manufacturing topsoil;
Soil aftercare; and
Uses for surplus topsoil
By considering soil as a valuable non-renewable resource from the outset of a project, and
not as a waste or a disposable commodity, the quality and agricultural capabilities of soils
can be retained, even following several years of storage. The result is that a range of
options for productive after uses remain viable, which could directly offset some of the
original impact of development.
It is often assumed that retaining soil resources on the construction site is the most
sustainable after-use option as it eliminates the time, cost and emissions associated with
haulage. However, many on-site after-uses for soils are redundant, including landscaping,
informal open green space and roadside tree planting.
If soil functions and qualities have been carefully preserved throughout the construction
process, then efforts should be made to return the soil resource to a productive use. On a
small scale, developers should seek to include allotments in development plans to
encourage productive re-use of the soils and to retain some of the agricultural capability of
the soils for the future. On a strategic scale, options could also be sought to deploy the
soils off-site for the purpose of improving agricultural land quality and production in the
vicinity of the development. In the context of the strategic development sites explored
and the wider Arun District, the Park Gate soil series is extensively mapped and is typically
wetter than many of the other soil series present. As stated in Section 3.11, the depth to a
slowly permeable layer is significant in determining the land grading according to soil
wetness. Therefore by increasing the depth of soil and in doing so also the distance to any
slowly permeable subsoil layer, there is the potential for drainage, and subsequently land
quality, to be improved.
Food Production and Security
Across the whole of the UK in 2011 3, 17.2 million hectares (70% of all land) was in
productive agricultural use. Of this area, 705 thousand hectares were planted with oilseed
rape, and 3.1 million hectares with cereal crops, both having increased from 2010 figures.
Grassland accounted for around 11 million hectares (including rough grazing, temporary
grass under 5 years old and permanent grassland).
Much of the agricultural land across the four strategic development sites assessed above,
collectively amounting to around 935ha, comprises grass, cereal and oilseed rape crops.
Loss of these crops to development would represent 0.006% of the national land area over
which grass, cereals and oilseed rape crops are grown, and hence would not be anticipated
to greatly impact national food production and security.
In the context of West Sussex, 29,700 hectares were used for cereals and oilseed rape, and
56,600 hectares for grass in 2010 4, totalling 86,300 hectares. Loss of 935 hectares of land
under these crops would represent a county wide loss of 1%. On the most local scale,
covering the three districts of Arun, Adur and Worthing, grass and cereal crops occupied
10,240 hectares of the land in 2010 (the area of oilseed rape crops is not available at this
scale). Loss of 935ha across the four strategic development sites would represent a
significant loss to the local supply of 9%.
The approximate contribution of each strategic site option to the loss of local grass and
cereal supply is as follows:
BREQ – 1%
Three Villages – 1.5%
Ford – 4%
Parish of Angmering – 2.5%
High value vegetables grown outdoors contributed 129,000 hectares to the national total
cropped area, and soft fruits and grapes, 10,000 hectares. In West Sussex in 2010, outdoor
vegetables occupied 2,233 hectares and top fruit and small fruit a further 491 hectares.
West Sussex alone is therefore responsible for around 2% of the total UK supply of fruit
and vegetables, and any loss to development will be difficult to absorb without the need
for increased imports.
Defra 2011. Agriculture in the United Kingdom 2011
Defra Statistics, 2010.
Across the three districts of Arun, Adur and Worthing, 331 hectares of land were used for
growing fruits and vegetables in 2010. The strategic development sites of BREQ and the
Parish of Angmering contain around 35 and 90 hectares of outdoor fruit and vegetable
crops respectively. Development of these sites would therefore involve the loss of almost
40% of local fruit and vegetable production, and 4.5% of the total production of West
Sussex. One quarter of local fruit and vegetable supply comes from the area to the east of
the A280 in the Parish of Angmering Site, highlighting its significance and importance for
local food security.
Unless alternative high quality land areas capable of supporting outdoor crops were found,
the districts would need to become heavily reliant on imports, either from elsewhere in the
UK or internationally depending upon factors such as demand, the capacity of suppliers to
increase their production and cost effectiveness, and hence further noticeable impacts on
the region would also be expected.
The impact of development on glasshouse production in Arun and the wider region would
be much smaller than on outdoor production as glasshouse systems often do not rely on
soil as a growing medium. However, while loss of productive land and soil to proposed
developments would have a much reduced impact on food production and security relating
to the horticultural aspect of agriculture, that soil is not imperative in glasshouses reduces
the possible productive afteruses of soils from development sites. The consequence of this
lack of demand may be that instead of being recycled into an alternative food production
system, the agricultural soil resource is more likely to become redundant.
Green Infrastructure Study
The NPPF defines Green Infrastructure (GI) as:
“a network of multi-functional green space, urban and rural, which is capable of delivering
a wide range of environmental and quality of life benefits for local communities.”
GI should deliver ecological services, recreational benefits, climate change mitigation, and
adaptation measures, and should enhance landscape character and distinctiveness. The
Arun GI Study makes reference to Productive Green Environments (PGEs) which include
best and most versatile agricultural land, the horticultural business sector of Arun, the
extensive woodland of the national park, and allotments across the district.
Best and most versatile agricultural land is stated as being a nationally and regionally
scarce resource and as such its protection is identified as a priority for Arun. However, as
shown above the distribution of best and most versatile land across Arun in comparison
with the wider regional and national contexts is such that the amount of development
stated as being necessary would not be possible if best and most versatile land were to be
avoided completely.
It is also important to note that best and most versatile quality agricultural land is classified
according to its capability for food production, which is an economic measure, and which
does not address the delivery aims of the GI study. Land of poorer agricultural quality (that
of Subgrade 3b, 4 and 5) will contribute more to the aims of the GI study, particularly if
under grass and rough grazing. While highly productive agricultural land supports
monocultures, i.e. a single crop type at any particular time, poor quality grassland will
support more diverse floral and faunal communities, simultaneously addressing the GI
aims of delivering ecological services and enhancing landscape character.
Organic matter inputs from livestock and a lack of ploughing and working by heavy
machinery mean that carbon storage is enhanced in poor quality agricultural land when
compared with higher quality land which is cropped and ploughed periodically. Water
retention and storage may also be better on poorer quality agricultural land, which is
therefore concluded to be of great importance for conservation, and climate change and
flood mitigation.
Best and most versatile quality agricultural land should not be preserved merely on the
basis that it has been classified so, as the ecological and social benefits of poorer quality
land are significant. Combined with the economic contribution made by the horticultural
sector, which is also identified as a productive green environment in need of preserving in
Arun, all three pillars of sustainability are addressed, even with some development of best
and most versatile agricultural land.
Limitations to the Study
The assessments of individual strategic development sites have been based on a wide
range of reliable data sources. However, no site inspections were carried out as part of
this study, which consequently can be used for guidance only. Land quality predictions
have been based on analysis and interpretation of the available data sources, but are not
The actual productivity of each site is not only dependent upon the climate and land
quality, but also upon the occupier of the site. For example, in reality, some areas of
particularly high quality land may be under grass and occupied by a livestock farmer, while
some areas of average quality land may be occupied by salad growers who have invested in
irrigation systems or technological fixes to artificially improve productivity.
The economic productivity estimations are based upon figures calculated on a per hectare
basis from statistics applicable to West Sussex and which were obtained from Defra. The
values used represent high and low extremes of the productivity of land, as they are based
on crop mixes which may not occur across all of the sites, but which are considered to be
representative in terms of the potential of the land. For example, fruit and vegetable crops
were included in the ‘high value’ calculations applied to all land of Grades 1 and 2, which
has the least restriction on its capability to produce consistently high yields of a wide range
of crops.
Fruit and vegetable crop areas were replaced with an equivalent area of wheat crop for the
‘average values’ applied to land of Subgrades 3a and 3b, which is unlikely to consistently
produce good yields of fruit and vegetable crops.
The high values were applied to Grades 1 and 2, and average values applied to Subgrades
3a and 3b, rather than applying high values to land of best and most versatile quality and
average value to land not of best and most versatile quality. The reason for this is, in
practice, the distinction between the Subgrades can be marginal. So, while Subgrade 3a is
considered best and most versatile quality, the output may really be no different to that
from nearby Subgrade 3b quality land.
The calculations of economic losses are made on a whole-site basis. Given the extent of
each site, in reality, it is likely that some agricultural land may be retained.
assessments made in this report are therefore applicable to a “worst case” scenario.
The Future
The future baseline for each strategic development site, for Arun District and for the wider
region will undoubtedly change with a number of variable factors.
Population Change
With a predicted population increase in Arun District of 26,000 by the year 2030, there will
be an associated increase in pressure on land for food production and the need for
housing, employment and recreational opportunities. Accommodating and supporting a
growing population sustainably requires a multi-faceted approach and must consider a
range of environmental, social and economic factors. A balance between the need for
social and economic development, and the inevitable loss of greenfield environments must
be found.
It is highly unlikely that there will be enough appropriate and financially viable brownfield
land available for development, and hence suitable greenfield sites will need to be
identified. As highlighted in Section 9, such sites should not be selected or rejected on the
basis of the assessed land quality, but should also take into account the other benefits,
services and functions that land and soils carry out. The strength of the horticultural
glasshouse sector in Arun and surrounding districts also decreases the significance of land
quality in development, as the impact on overall future food production is likely to be
much less severe than in areas where all crops are grown outdoors.
Climate Change
Climate change is the factor over which we have the least control and difficulties in
predicting exactly how and how fast the climate will change presents challenges for
managers of soils, land and development.
Under low emissions scenarios for the south east of England, mean temperatures are
predicted to rise by 1.5°C and annual precipitation by 1% in the 2020's. Climate is an
overarching factor in the determination of land quality and in the capability of areas to
produce quality crops. Warmer temperatures and maintained water supply in the future
should be beneficial for crop growth. However, the interaction of climate with soil factors
may be such that soil droughtiness is exacerbated, potentially to the noticeable detriment
of crops.
Any increase in precipitation and alterations to the frequency and intensity of rainfall will
impact upon soil wetness and the number of field capacity days, as well as flood risk.
Depending upon the extent to which soil wetness presents a limitation to the ALC baseline
of a site, crop growth and the ease with which fields can be accessed and worked by
farming machinery could be adversely affected, hindering localised outdoor food
Technological Fix
Technology is almost certain to play a key role in the future of food production, locally,
nationally and even globally, in sectors including crop development, farming technique and
glasshouse development.
Engineering of new crop varieties which are drought tolerant, disease resistant and
consistently higher yielding has the potential to mitigate the impacts of climate change,
population growth and decreasing land availability on food production.
Using technology to enhance the efficiency of farming activities will also contribute to
securing food supply. Ongoing research into the incorporation of GPS technology into farm
machinery aims to maximise the efficiency of fertiliser and pesticide delivery, thus
providing the optimum amount of nutrients needed by plants (with the ability to change
nutrient delivery rates in different areas of individual fields if needed) and in doing so
decreasing unnecessary emissions of chemical residues to air and water.
Opportunities should be taken across West Sussex to be at the forefront of glasshouse
development, through the establishment of combined horticultural and energy hubs 5.
These hubs utilise waste and emissions, either by recycling them within the crop
production system, or through the generation of energy which can be used on site or sold
off-site. The result is reduced emissions from the horticultural sector, increased crop
production efficiency and financial viability, and increased local employment opportunities
across a range of roles.
Technological innovation as described above could greatly reduce externalities in the
future. An externality is an effect arising from the production or consumption of goods,
which affects a third party. For example, in the agricultural sector, externalities include the
negative impact on water quality which can occur through diffuse pollution from farmland
pesticides, or the release of carbon dioxide from glasshouses into the atmosphere.
Stricter regulation of waste and emissions, and increases in penalties such as landfill tax,
mean that producers have to address their externalities either by increasing their costs or
by decreasing their waste, which requires businesses and their processes to become more
WSGA Combined Horticultural Production and Energy Hubs: A Review, October 2012.
With rapid population growth predicted in the Arun District and West Sussex, and the
associated increased pressures on land to produce more food, a soft, ecocentric approach
to mitigate the impacts of externalities is not viable on a large scale and hence the
approach of technological fix is likely to be needed if the region is to cope. Although not
addressing the cause of the problem (population growth), technologically “fixing”
externalities such as emissions in the future has the potential to improve social, economic
and environmental conditions, so addressing each of the three pillars of sustainability.
Bioeconomy Strategy
The Europe-wide Strategy (described in Section 2) is a relatively little known about
document but should be a key piece of literature forming the basis of future policies and
development strategies.
Given that future changes to population dynamics, resource depletion and changes to land
use are inevitable, an holistic approach to impact mitigation as stated in the document is
likely to produce the best outcomes for both the environment and the economy.
Communication at and between all levels, from central government to individual farmers,
will give new policies longevity, by ensuring national aims are achieved while remaining
applicable and easy to implement on a day-to-day basis.
Significant population growth is predicted across West Sussex and the Arun District within
the coming decades.
This expansion will require development of residential and
employment opportunities in the District to accommodate the needs of the growing
population, and such development should be consistent with environmental, social and
economic sustainability aims.
Four Strategic Development Sites have been identified in the Arun District: the Bognor
Regis Eco-Quarter, land at the Three Villages, land at Ford and the Parish of Angmering. All
of the sites contain proportions of best and most versatile quality agricultural land which
greatly exceed regional and national averages, and hence any of the development thought
to be required in the district is going to impose a significant loss of this resource.
However, agricultural land quality assessments are essentially an economic measure of
how capable the land is to produce crops, and do not take into account other advantages
of agricultural land, such as carbon storage, support of biodiversity or flood mitigation.
Lower quality land often provides these environmental services better than the highest
quality land, which is more likely to be intensively farmed.
When identifying sites for development (and assuming the availability of brownfield sites
have been explored), it is therefore for local planning authorities to evaluate which is of
most benefit: the economic advantages of protecting high quality land, or the
environmental advantages of protecting lower quality land. A balance between the two
may provide the best solution in areas where greenfield land is to be developed.
Arun’s horticultural sector should not be greatly impacted by any loss of agricultural land,
given that glasshouse production systems do not typically rely heavily on soil as a growing
medium. The contribution of this sector to national fruit and vegetable production is
significant, and future development of integrated horticultural production and energy hubs
should be explored.
Mitigation measures for the loss of agricultural land, whether best and most versatile
quality or not, should be adopted and should recognise and prioritise soil as a valuable and
non-renewable resource. By taking care to maintain the properties of the soil throughout
the construction process, faster and more successful re-establishment of the functions and
services soil provides becomes possible.
By finding a balance between the need for development; the relative environmental, social
and economic benefits of agricultural land; and anticipation of the potential positive and
negative impacts of climate change, policy shifts and scientific research, strategic
development in Arun District will be capable of accommodating a growing population
without jeopardising food security for the future.
Average Annual Gross Margin
Agricultural Land Classification
Arable crop
A crop sown in cultivated land: in this context applies to
cereal or other combinable crops and root crops.
Best and most versatile land
Land in Grades 1, 2 and 3a of the MAFF ALC
Department for Environment, Food and Rural Affairs
The combined process of both evaporation of water from
plant and soil surfaces, and loss of water through plant
stomata in the process of transpiration.
Ministry of Agriculture, Fisheries and Food
Slowly Permeable Layer (SPL)
A layer at least 15 cm in thickness with the upper boundary
within 80 cm of the surface and with soil textural and
structural characteristics that impede the downward
movement of excess rainfall
Soil profile
A vertical section of a soil.
Soil structure
The combination or arrangement of individual soil particles
into larger compound units (or peds) with channels between.
The secondary units are characterised and classified on the
basis of size, shape and degree of development.
Soil texture
The relative proportion of the various soil particle size
fractions in a soil (sand, silt and clay).
Wetness Class
Soil wetness is classified according to the depth and
duration of waterlogging in the soil profile. Six wetness
classes are identified, from very well to very poorly drained.
V & VI
Well drained
Moderately well drained
Imperfectly drained
Poorly drained
Very poorly drained/wet
Appendix 1: Methodology for assessing land gross margins
The value of agricultural land has been calculated on a per hectare basis, using two values: high and
average, which refer to the potential crop yields obtainable from the land. It has been assumed in
this study that land of agricultural land quality Grades 1 and 2 (excellent to very good quality land)
will produce high crops yields, and that land of Subgrades 3a and 3b (good to moderate quality land)
will produce average crop yields.
Using food and farming statistics obtained from Defra’s June 2010 survey results, the cropping mix
across the total farming area of West Sussex could be calculated. Values for horticultural crops were
included in the assessment of high yielding land, but were replaced with an equivalent area of wheat
crop for the average yielding land, as this is a more representative crop for the associated land
The values of each crop within the cropping mix were derived from the John Nix Farm Management
Handbook 43rd edition (2013), which gives gross margin values for high and average yields of crops
per hectare grown.
The percentage of the total land area covered by each crop (CA%) was calculated by dividing the
area of the crop (TCA) by the total farmed area (TA) of West Sussex, and multiplying by 100.
TCA/TA*100 = CA%
The gross margin of one hectare (GMha) of a given crop (taken from Nix, 2013) was multiplied by the
percentage of the total farmed area in West Sussex occupied by that crop (CA%). This figure
represents the number of hectares out of 100 hectares (or 100%) which the crop would occupy given
the crop mix of West Sussex. Dividing this by 100 gives the representative gross margin of the crop
within one representative hectare (GMrep).
GMha*(CA%/100) = GMrep
Some cereal crop examples are given below:
Farming Area
West Sussex
Arable crops
TA (ha)
TCA (ha)
Winter barley
TCA (ha)
Spring barley
TCA (ha)
TCA (ha)
Crop % of total
Crop GM per ha
GMha (high)
GMrep (£)
Crop GM per ha
GMha (average)
GMrep (£)
These GM per representative hectare were then multiplied across the number of hectares at each
Strategic Development Site containing either Grade 1 or 2 land (high yield values), or Subgrades 3a
or 3b land (average values) to give a total average annual gross margin per hectare.
Download PDF