NATIONAL UNIVERSITY OF IRELAND GALWAY CHEMICAL AMENDMENT OF DAIRY CATTLE SLURRY FOR THE CONTROL OF PHOSPHORUS IN RUNOFF FROM GRASSLAND Raymond B. Brennan, B.E. Research Supervisors: Dr. Mark G. Healy, Civil Engineering NUI Galway Dr. Owen Fenton, Teagasc, Johnstown Castle, Wexford Professor of Civil Engineering: Padraic E. O‘Donoghue Thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy. September 2011 The National University of Ireland requires the signatures of all persons using or photocopying this thesis. Please sign below, and give the address and date. ii I would like to dedicate this work to my wonderful family, and to the memory of Eileen Armstrong, Helena Brennan and baby Helena Brennan. iii ‗Don't let your success determine your attitude, let your attitude determine your success.‘ (Adapted from Ken Brown) iv ABSTRACT Phosphorus (P) loss from grassland to a waterbody can adversely affect water quality. Land application of dairy cattle slurry can result in incidental P losses to runoff in addition to increased chronic P losses from soil as a result of a build-up in Soil Test P (STP). A literature review identified chemical amendment of dairy cattle slurry as a possible mitigation measure to prevent such losses. This study comprised laboratory and field-scale experiments, which investigated the effectiveness and feasibility of chemical amendments in reducing P solubility, taking into account for the first time their pollution swapping potential. First, a controlled agitator experiment was designed to identify the most effective chemical amendment to reduce Dissolved Reactive Phosphorus (DRP) release to water overlying grassed soil cores, which received un-amended and amended dairy cattle slurry. In addition to effectiveness, the feasibility of these amendments was determined based on several criteria: estimated cost of amendment, amendment delivery to farm, addition of amendment to slurry, and slurry spreading costs due to any volume increases. The four best amendments based on effectiveness and feasibility, at optimum application rates were: ferric chloride (FeCl2), which reduced the DRP in overlying water by 88%, aluminium chloride (AlCl3) (87%), alum (83%) and lime (81%). These amendments were then added to slurry immediately before it was surface applied to grassed soil in runoff boxes, which were subjected to simulated rainfall events. Analysis of overland flow showed that PAC (Poly-Aluminium Chloride, a commercially available form of AlCl3) was the most effective amendment for decreasing DRP losses in runoff following slurry application, while alum proved to be the most effective for total P (TP) and particulate P (PP) reduction. The incidental loss of metals (aluminium (Al), calcium (Ca) and iron (Fe)) in runoff during all experiments was below the maximum allowable concentrations (MAC) for receiving waters. Once the effectiveness of the amendments under laboratory conditions were quantified, their ‗pollution swapping‘ potential was examined. A laboratory-scale gas chamber experiment was conducted to examine emissions of ammonia (NH3), nitrous oxide (N2O), v methane (CH4) and carbon dioxide (CO2). After considering pollution swapping in conjunction with amendment effectiveness, the amendments recommended for a micro plot study were, from best to worst: PAC, alum and lime. This component of the study investigated how soil and chemically amended slurry interactions affect amendment effectiveness under field conditions. The results of this micro-plot study validated the results from the laboratory-scale studies. Alum and PAC reduced average flow-weighted mean concentration (FWMC) and total loads of DRP, dissolved un-reactive phosphorus (DUP), PP and TP in runoff, while amendment of slurry with lime at the rate examined in this study was not effective at reducing P losses. Alum amendment significantly increased average FWMC of ammonium-N (NH4-N) in runoff water during the first rainfall event after the slurry was applied (an 84% increase). This indicates that chemical amendment of dairy cattle slurry conducted on a large scale could increase soluble N losses. Finally, a 9-month incubation experiment was conducted using five Irish grassland soils to examine the effect of amendments on the long-term plant availability of P in soil and the effect of soil type on the stability of reductions in P solubility. The study showed that, with the exception of FeCl2, the chemical amendments reduced water extractable phosphorus (WEP) without affecting STP. This study showed that amendments are effective and that there is no major risk of pollution swapping associated with alum and PAC. This is a significant finding as there is now potential to use amendments strategically, in combination with existing POM (programme of measures), to mitigate P losses. The next step will be to examine the use of chemical amendments at catchment-scale. It is hoped that there will be economic incentives given to farmers to reduce nutrient losses. It is possible that P mitigating methods, such as chemical amendment of dairy cattle slurry, may be used strategically within a catchment to bind P in cow and pig slurries. vi DECLARATION This dissertation is the result of my own work, except where explicit reference is made to the work of others, and has not been submitted for another qualification to this or any other university. Raymond Brennan vii ACKNOWLEDGEMENTS I wish to thank An tOllamh Padraic O‘Donoghue for his encouragement and help during the research study and during the preparation of this thesis. I am grateful to Teagasc for providing a Walsh fellowship and funding for this project, and to the authorities in the National University of Ireland, Galway for providing the facilities to carry out the research work. I would like to express my gratitude to my NUI, Galway supervisor, Dr. Mark Healy and my Teagasc supervisor, Dr. Owen Fenton, who were always encouraging, patient and generous with their time. It has been a wonderful experience working with them and I owe them my deepest gratitude. I have been very fortunate and received help from many people along the way. I would however like to express a special thanks to Drs. Gary Lanigan and Jim Grant for their time and patience. This work would not have been possible without tremendous cooperation and help from many people, in particular technical staff in Johnstown Castle, Teagasc in Athenry and NUI Galway. A special thanks to Ana Serrenho, Kathy Carney, Maja Drapiewska, Mary O‘Brien, Peter Fahy, Gerry Hynes, Aoife Keady, Liwen Xiao, Eoghan Clifford, Denis Brennan, Stan Lalor, Theresa Cowman, Linda Finn, Paddy Sills, Pat Donnelly, Paddy Hayes and Maria Radford. I would also like to extend a special thanks to John Regan for setting up the rainfall simulator and for training me in the lab. I wish to thank my fellow post-grads for their support and time. I also wish to thank the tag rugby team, past and present, for giving me something to look forward to all summer. I have enjoyed my time in NUI Galway immensely and I will always hold my memories of my time in university close to my heart. I wish to thank my friends for their support and patience, especially Joe McGovern for managing to live with me through most of the PhD. I would also to thank my girlfriend, Joanne, for being so kind, encouraging and understanding. Finally, I would like to thank my wonderful father, Michael, and my brothers, Michael, Kieran, Bernard, Dermot and Shane, for their support and endless encouragement throughout this process. viii ABBREVIATIONS a A constant related to the binding strength of molecules onto the amendments AD Anaerobic digestion Al Aluminium AlCl3 Aluminium chloride Al2O3 Aluminium oxide Alum aluminium sulphate (analytical grade (Al2(SO4)3nH2O) and commercial grade) Al-WTR-1 Al-WTR-alum-based water treatment residual which was dried and crushed to pass 2 mm sieve Al-WTR-2 Al-WTR-alum-based water treatment residual in sludge form AOD Above ordnance datum APHA American Public Health Association AVC Ammonia volatilisation chamber b The theoretical amount of P adsorbed to form a complete monolayer on the surface bgl Below ground level BOD5 Five day biological oxygen demand BS British Standards C The final P concentration of the solution in isotherm test Ca Calcium CaCO3 Calcium carbonate CaCl2 Calcium chloride Ca(OH)2 Lime CC Container capacity approximate field capacity in incubation experiment Ce The concentration of P in solution at equilibrium (mg L-1) CH4 Methane CO2 Carbon dioxide ix CSA Critical source areas CSO Central Statistics Office CWs Constructed wetlands DAFF Department of Agriculture, Fisheries and Food d Day DM Dry matter DRP Dissolved reactive phosphorus DUP Dissolved un-reactive phosphorus EC Electrical conductivity EEC European Economic Community EPA Environment Protection Agency EPC0 Equilibrium P concentration (i.e. the point where no net desorption or sorption occurs) in Langmuir Isotherm EU European Union Fe Iron FeCl2 Ferrous chloride FeCL3 Ferric chloride FeSO4 Ferric chloride FGD Flue gas desulphurization FWMC Flow-weighted mean concentration FWS Free water surface GHG Green house gas GWP Global warming potential H Hour ha Hectare H2 Hydrogen gas H2S Hydrogen sulphide H2SO4 Sulphuric acid HCl Hydrochloric acid ICP Inductive coupled plasma IPCC Intergovernmental Panel on Climate Change x K Potassium kd The slope of the relationship between S‘ and C LOI Loss on ignition M3 Mehlich-III P MAC Max allowable concentration Mg Magnesium MgCl2 Magnesium chloride N Nitrogen mo Month N2 Nitrogen gas N2O Nitrous oxide NH3 Ammonia NH4 Ammonium NH4 Ammonium ion NH4-N Ammonium nitrogen NO2 Nitrite NO2-N Nitrite nitrogen NO3 Nitrate NO3-N Nitrate nitrogen OJEC Official Journal of the European Community OM Organic matter P Phosphorus PAA Photo-acoustic-analyser PAC Poly-aluminium chloride PAM Polyacrylamide PDS Particle size distribution POM Programme of measurements PP Particulate phosphorus PSM Phosphorus sorbing material R2 Regression coefficient RS1 Rainfall simulation event 1 xi RS2 Rainfall simulation event 2 RS3 Rainfall simulation event 3 rpm Revolutions per minute S' The mass of P adsorbed from slurry (mg kg-1), S0 The amount of P originally sorbed to the amendment (mg L-1) SAS Statistical Analysis Software SI Statutory Instrument SS Suspended sediment STP Soil test phosphorus T0.5 The time for half of ammonia losses to occur TAN Total ammonical nitrogen TDP Total dissolved phosphorus in water TDS Total dissolved solids TK Total potassium TN Total nitrogen TON Total oxidized nitrogen TP Total phosphorus TR Time from commencement of simulated rainfall event and start of runoff UK United Nations UN United Nations U.S.A. United States of America USDA United States Department of Agriculture USEPA United States Environment Protection Agency WEP Water extractable phosphorus WFD Water Framework Directive WTR Water treatment residuals x/m The mass of P adsorbed per unit mass of amendments (g kg-1) at Ce Ω Stream power of overland flow xii TABLE OF CONTENTS ABBREVIATIONS ..................................................................................... IX LIST OF FIGURES ................................................................................XVIII LIST OF TABLES ..................................................................................XXIII CHAPTER 1 INTRODUCTION ................................................................................ 1 1.1. OVERVIEW.............................................................................................. 1 1.2. PROCEDURE............................................................................................ 3 1.3. STRUCTURE OF DISSERTATION .............................................................. 4 CHAPTER 2 LITERATURE REVIEW .................................................................... 6 2.1. OVERVIEW.............................................................................................. 6 2.2. AGRICULTURE IN IRELAND .................................................................... 6 2.3. LEGISLATION AND COMPLIANCE ........................................................... 8 2.4. CURRENT WATER QUALITY STATUS IN IRELAND .................................. 8 2.5. IMPACT OF AGRICULTURE ON WATER QUALITY ................................. 10 2.6. NUTRIENTS LOSS AND PATHWAYS DURING LAND APPLICATION OF DAIRY SLURRY ......................................................................................................... 11 2.7. PHOSPHORUS ........................................................................................ 11 2.7.1. 2.7.2. 2.8. Phosphorus in soil ............................................................................. 12 Methods used to determine risk of P loss to water ........................... 12 NITROGEN ............................................................................................ 16 2.9. LOSS OF SOLUBLE AND PARTICULATE NUTRIENTS IN RUNOFF............ 19 2.9.1. 2.9.2. 2.10. Soluble nutrient loss .......................................................................... 19 Particulate nutrient loss ..................................................................... 20 GASEOUS EMISSIONS AND THE IMPORTANCE OF CONSIDERING POLLUTION SWAPPING WHEN SELECTING A P MITIGATION MEASURE .................. 24 2.11. PRESENT AND EMERGING P MITIGATION MEASURES .......................... 24 2.11.1. 2.11.2. 2.11.3. 2.11.4. 2.11.5. 2.11.6. 2.11.7. Constructed wetlands ...................................................................... 25 Anaerobic digestion ......................................................................... 27 Biochar ............................................................................................ 29 Buffer strips and enhanced buffer strips.......................................... 30 Composting ..................................................................................... 31 In-stream and edge of field filters ................................................... 32 Sand and woodchip filter systems ................................................... 35 xiii 2.11.8. Slurry separation.............................................................................. 35 2.11.9. Use of P sorbing amendments ......................................................... 37 2.11.9.1. 2.11.9.2. 2.12. Amendments applied directly to soil ..............................................37 Amendments to slurry ....................................................................38 RECOMMENDATIONS AND KNOWLEDGE GAPS .................................... 40 CHAPTER 3 EVALUATION OF CHEMICAL AMENDMENTS TO CONTROL PHOSPHORUS LOSSES FROM DAIRY SLURRY .................................................. 42 3.1. OVERVIEW............................................................................................ 42 3.2. INTRODUCTION..................................................................................... 42 3.3. MATERIALS AND METHODS .................................................................. 43 3.3.1. 3.3.2. 3.3.3. 3.3.4. 3.3.5. 3.3.6. 3.3.7. Soil preparation and analysis ............................................................ 43 Slurry sampling and analysis ............................................................ 45 PSM sourcing and analysis ............................................................... 45 Agitator test ....................................................................................... 46 Water sampling and analysis ............................................................ 50 Statistical Analysis ............................................................................ 50 Cost analysis ..................................................................................... 50 RESULTS ............................................................................................... 51 3.4.1. 3.4.2. 3.5. Results of agitator test ....................................................................... 51 Cost and feasibility analysis.............................................................. 53 DISCUSSION .......................................................................................... 56 3.6. CONCLUSIONS ...................................................................................... 58 3.7. SUMMARY ............................................................................................. 58 3.4. CHAPTER 4 LABORATORY-SCALE RAINFALL SIMULATION EXPERIMENT 59 4.1. OVERVIEW............................................................................................ 59 4.2. INTRODUCTION..................................................................................... 59 4.3. MATERIALS AND METHODS ................................................................. 60 4.3.1. 4.3.2. 4.3.3. 4.3.4. 4.3.5. Soil sample collection and analysis .................................................. 60 Slurry collection and analysis ........................................................... 60 Slurry amendment and runoff set-up ................................................ 61 Sample handling and analysis ........................................................... 67 Statistical analysis ............................................................................. 67 RESULTS ............................................................................................... 68 4.4.1. 4.4.2. 4.4.3. Slurry and amended slurry analysis .................................................. 68 Water quality analysis ....................................................................... 69 Metals in runoff water ....................................................................... 73 DISCUSSION .......................................................................................... 76 4.4. 4.5. xiv 4.5.1. 4.5.2. 4.5.3. 4.6. Slurry and amended slurry analysis .................................................. 76 Water quality ..................................................................................... 77 Metals in runoff water ....................................................................... 79 CONCLUSIONS ...................................................................................... 80 4.7. SUMMARY ............................................................................................. 81 CHAPTER 5 EFFECT OF CHEMICAL AMENDMENT OF DAIRY CATTLE SLURRY ON GREENHOUSE GAS AND AMMONIA EMISSIONS ...................... 82 5.1. OVERVIEW............................................................................................ 82 5.2. INTRODUCTION..................................................................................... 82 5.3. MATERIALS AND METHODS ................................................................. 83 5.3.1. 5.3.2. 5.3.3. 5.3.4. 5.3.5. 5.3.6. Soil sample collection and analysis .................................................. 83 Dairy slurry collection and analysis .................................................. 84 Chemical amendment of slurry ......................................................... 84 Measurement of ammonia................................................................. 85 Measurement of CH4, N2O and CO2 ................................................. 87 Statistical analysis ............................................................................. 87 RESULTS ............................................................................................... 88 5.4.1. 5.4.2. 5.4.3. 5.4.4. 5.4.5. 5.4.6. Slurry and amended slurry results..................................................... 88 Ammonia........................................................................................... 89 Nitrous oxide ..................................................................................... 91 Carbon dioxide .................................................................................. 91 Methane emissions ............................................................................ 94 Impact of amendments on global warming potential ........................ 95 DISCUSSION .......................................................................................... 97 5.5.1. 5.5.2. 5.5.3. 5.5.4. 5.6. Ammonia emissions .......................................................................... 97 Nitrous oxide ..................................................................................... 99 Carbon emissions ............................................................................ 100 Impacts of pollution swapping ........................................................ 101 CONCLUSIONS .................................................................................... 102 5.7. SUMMARY ........................................................................................... 103 CHAPTER 6 PLOT-SCALE RAINFALL SIMULATION STUDY ................... 104 6.1. OVERVIEW.......................................................................................... 104 6.2. INTRODUCTION................................................................................... 104 6.3. MATERIALS AND METHODS ............................................................... 105 5.4. 5.5. 6.3.1. 6.3.2. 6.3.3. 6.3.4. 6.3.5. Study site ......................................................................................... 105 Slurry analysis ................................................................................. 107 Treatments....................................................................................... 109 Rainfall simulation .......................................................................... 110 Statistical analysis ........................................................................... 113 xv 6.4. RESULTS ............................................................................................. 114 6.4.1. 6.4.2. 6.4.3. 6.5. Phosphorus (FWMC of DRP, DUP, PP and TP) ............................ 114 Nitrogen .......................................................................................... 116 Time to runoff, soil volumetric water content and runoff volume . 117 DISCUSSION ........................................................................................ 119 6.5.1. Phosphorus (FWMC of DRP, DUP, PP and TP) ............................ 119 6.5.2. Nitrogen .......................................................................................... 120 6.5.3. Rainfall intensity, soil volumetric water content, time to runoff and runoff volume ............................................................................................... 121 6.5.4. Outlook for future implementation of chemical amendment of dairy cattle slurry as a management practice for high P soils ............................... 122 6.6. CONCLUSIONS .................................................................................... 124 6.7. SUMMARY ........................................................................................... 124 CHAPTER 7 THE LONG-TERM IMPACT OF THE ADDITION OF CHEMICALLY AMENDED DAIRY SLURRY ON PHOSPHORUS CONTENT AND PH OF FIVE SOIL TYPES ................................................................................ 125 7.1. OVERVIEW.......................................................................................... 125 7.2. INTRODUCTION................................................................................... 125 7.3. MATERIALS AND METHODS ................................................................ 126 7.3.1. 7.3.2. 7.3.3. 7.3.4. Soil collection and analysis ............................................................. 126 Slurry collection and analysis ......................................................... 126 Incubation experiment .................................................................... 128 Statistical analysis ........................................................................... 131 RESULTS ............................................................................................. 132 7.4.1. 7.4.2. 7.4.3. Water extractable phosphorus ......................................................... 132 Soil test phosphorus ........................................................................ 133 Soil pH ............................................................................................ 134 DISCUSSION ........................................................................................ 134 7.5.1. 7.5.2. 7.5.3. 7.6. WEP ................................................................................................ 134 Soil test phosphorus ........................................................................ 139 Soil pH ............................................................................................ 139 CONCLUSIONS .................................................................................... 140 7.7. SUMMARY ........................................................................................... 140 CHAPTER 8 CONCLUSIONS AND RECOMMENDATIONS ......................... 141 8.1. OVERVIEW.......................................................................................... 141 8.2. CONCLUSIONS .................................................................................... 141 8.3. RECOMMENDATIONS FOR FUTURE WORK ......................................... 143 8.4. CONTEXT ............................................................................................ 144 7.4. 7.5. xvi REFERENCES .............................................................................................................. 146 APPENDIX ................................................................................................... 171 APPENDIX A LIST OF PUBLICATIONS ................................................................................... 172 APPENDIX B RESULTS OF AGITATOR TEST ........................................................................... 174 APPENDIX C RUNOFF BOX STUDY RESULTS ......................................................................... 194 APPENDIX D RESULTS FROM CHAPTER 5 ........................................................................... 212 APPENDIX E PHOTOGRAPHS OF SLURRY AND AMENDED SLURRY APPLIED TO PLOTS (CHAPTER 6) ............................................................................................................................. 238 APPENDIX F RESULTS OF PLOT STUDY................................................................................ 240 APPENDIX G INCUBATION STUDY RESULTS ......................................................................... 259 xvii LIST OF FIGURES FIGURE 2.1 NUMBER OF GROUND WATER MONITORING SITES WITH PHOSPHATE CONCENTRATIONS FROM 1995 TO 2009 (MCGARRIGLE ET AL., 2011) ................................................................................................................... 9 FIGURE 2.2 NUMBER OF REPORTED FISH KILLS ATTRIBUTED TO AGRICULTURE, INDUSTRY, LOCAL AUTHORITY, OTHER AND UNKNOWN SOURCES (MCGARRIGLE ET AL., 2011) ..................................... 10 FIGURE 2.3 THE SOIL P CYCLE: ITS COMPONENTS AND MEASURABLE FRACTIONS (STEWARD AND SHARPLEY, 1987) ............................................ 13 FIGURE 2.4 SCHEMATIC OF THE SOIL N CYCLE (KETTERINGS ET AL., 2011) 17 FIGURE 2.5 RELATIONSHIP BETWEEN THE AMMONIA/AMMONIUM (NH3/NH4+) RATIO AND PH (GAY AND KNOWLTON, 2005) .......................... 18 FIGURE 2.6 DETACHMENT OF SOIL PARTICLES IN A RAINFALL EVENT (ROSE, 2004) ............................................................................................................ 21 FIGURE 2.7 RATE OF SEDIMENT DEPOSITION IN SURFACE RUNOFF (ROSE, 2004) ......................................................................................................................... 22 FIGURE 2.8 ENTRAINMENT AND RE-ENTRAINMENT OF SEDIMENT (ROSE, 2004). ........................................................................................................................ 23 FIGURE 2.9 COMPOST FILLED SOCKS IN INSTRUMENTED DRAINAGE CHANNEL (SHIPITALO ET AL., 2010A) ............................................................. 33 FIGURE 2.10 PERMEABLE EDGE OF FIELD BARRIERS (O‘CONNOR ET AL., 2010) ......................................................................................................................... 34 FIGURE 2.11 SCHEMATIC AND PHOTO OF FERRIC-SULPHATE DOSER IN OPERATION IN JOKIOINEN, FINLAND (NARVANEN ET AL., 2008) ............ 35 FIGURE 2.12 PILOT SCALE WOOD CHIP FILTER USED TO TREAT THE LIQUID PORTION OF PIG SLURRY FOLLOWING SEPARATION (CARNEY ET AL., 2011) ......................................................................................................................... 36 FIGURE 3.1 BEAKERS PLACED IN FLOCCULATOR DURING AGITATOR TEST ................................................................................................................................... 43 xviii FIGURE 3.2 UNITED STATES DEPARTMENT OF AGRICULTURE (USDA) SOIL TEXTURE CLASSIFICATION TRIANGLE USED TO DETERMINE SOIL TEXTURE ................................................................................................................ 44 FIGURE 3.3 SCHEMATIC DIAGRAM OF SOIL SAMPLE IN AGITATOR .............. 48 FIGURE 3.4 PHOSPHORUS CLASSIFICATION SYSTEM USED IN THIS STUDY (APHA, 1995) ........................................................................................................... 51 FIGURE 3.5 MASS OF DRP AND DRP CONCENTRATION IN OVERLYING WATER .................................................................................................................... 52 FIGURE 3.6 TOTAL COST OF CHEMICAL AMENDMENT OF DAIRY CATTLE SLURRY PLOTTED AGAINST THE REDUCTION IN DISSOLVED REACTIVE PHOSPHORUS (DRP) LOST TO OVERLYING WATER AND THE PERCENTAGE REDUCTION IN DRP RELEASE TO OVERLYING WATER .. 53 FIGURE 3.7 HISTOGRAM OF SLURRY PH AT TIME OF AMENDMENT/APPLICATION (CLEAR BOX) AND PH OF SLURRY AFTER 24 H (HATCHED BOX) .......................................................................................... 55 FIGURE 4.1 LANGMUIR ISOTHERM FITTED TO PHOSPHORUS IN AMENDED SLURRY DATA ....................................................................................................... 62 FIGURE 4.2 PHOSPHORUS SORPTION ISOTHERMS FOR AMENDED SLURRY DATA ....................................................................................................................... 63 FIGURE 4.3 RUNOFF BOX IMMEDIATELY (A) BEFORE AND (B) AFTER SLURRY APPLICATION........................................................................................ 65 FIGURE 4.4 PHOTOGRAPHS SHOWING SOIL SOD PREPARATION AND PLACEMENT METHODOLOGY .......................................................................... 66 FIGURE 4.5 PHOTOGRAPHS OF SLURRY AND AMENDED SLURRY IMMEDIATELY AFTER APPLICATION TO GRASSED SOIL IN BOXES ....... 69 FIGURE 4.6 THE AVERAGE FLOW-WEIGHTED MEAN CONCENTRATION OF DISSOLVED REACTIVE PHOSPHORUS (DRP), DISSOLVED UNREACTIVE PHOSPHORUS (DUP) AND PARTICULATE PHOSPHORUS (PP), WHICH COMPRISE TOTAL PHOSPHORUS (TP) IN RUNOFF FROM THREE RAINFALL SIMULATION EVENTS..................................................................... 71 xix FIGURE 4.7 THE AVERAGE % OF DISSOLVED REACTIVE PHOSPHORUS (DRP) DISSOLVED UNREACTIVE PHOSPHORUS (DUP) AND PARTICULATE PHOSPHORUS (PP), WHICH COMPRISE TOTAL PHOSPHORUS (TP) IN RUNOFF AFTER THREE RAINFALL SIMULATION EVENTS ........................ 73 FIGURE 4.8 AVERAGE FLOW-WEIGHTED MEAN CONCENTRATIONS OF SUSPENDED SEDIMENT IN RUNOFF ................................................................ 74 FIGURE 4.9 AVERAGE FLOW-WEIGHTED MEAN CONCENTRATIONS OF AL IN RUNOFF AND RAIN WATER ............................................................................... 75 FIGURE 4.10 AVERAGE FLOW-WEIGHTED MEAN CONCENTRATIONS OF CA IN RUNOFF AND RAIN WATER .......................................................................... 75 FIGURE 4.11 AVERAGE FLOW-WEIGHTED MEAN CONCENTRATIONS OF FE IN RUNOFF AND RAIN WATER .......................................................................... 76 FIGURE 5.1 PHOTOGRAPH OF DYNAMIC CHAMBER APPARATUS ................... 83 FIGURE 5.2 DIAGRAM OF APPARATUS USED TO MEASURE AMMONIA EMISSIONS ............................................................................................................. 85 FIGURE 5.3 DYNAMIC CHAMBER ............................................................................. 86 FIGURE 5.4 PHOTOGRAPH OF PAA DURING CARBON DIOXIDE, METHANE AND NITROUS OXIDE MEASURING PERIOD .................................................. 88 FIGURE 5.5 CUMULATIVE AMMONIA EMISSIONS FROM UNTREATED AND CHEMICALLY AMENDED SLURRY EXPRESSED AS A PERCENTAGE OF TOTAL NITROGEN IN SLURRY AND AMMONIACAL NITROGEN IN SLURRY ................................................................................................................... 90 FIGURE 5.6 NITROUS OXIDE EMISSIONS FROM SLURRY AND AMENDED SLURRY IN CHAMBERS (MEAN ± STANDARD ERROR) ............................... 92 FIGURE 5.7 CARBON DIOXIDE EMISSIONS FROM SLURRY AND AMENDED SLURRY IN CHAMBERS. (MEAN ± STANDARD ERROR) .............................. 93 FIGURE 5.8 CUMULATIVE CARBON DIOXIDE EMISSIONS FROM CHAMBERS FOR DURATION OF STUDY. (MEAN ± STANDARD ERROR) ........................ 93 FIGURE 5.9 METHANE EMISSIONS FROM SLURRY AND AMENDED SLURRY IN CHAMBERS. (MEAN ± STANDARD ERROR)............................................... 94 xx FIGURE 5.10 NITROGEN CUMULATIVE EMISSIONS (NITROUS OXIDE AND INDIRECT EMISSIONS RESULTING FROM AMMONIA LOSSES) EXPRESSED IN CO2 EQUIVALENTS. (MEAN ± STANDARD ERROR) ......... 95 FIGURE 5.11 CUMULATIVE CARBON DIOXIDE (CO2), INDIRECT NITROUS OXIDE (N2O), DIRECT N2O AND METHANE (CH4) MEASURED DURING THE STUDY EXPRESSED IN CO2 EQUIVALENTS. (MEAN ± STANDARD ERROR) .................................................................................................................... 96 FIGURE 5.12 RELATIONSHIP BETWEEN SLURRY AND AMENDED SLURRY PH AT TIME OF APPLICATION AND (A) CUMULATIVE NH3 EMISSIONS AND (B) AND LOG OF TIME FOR HALF OF AMMONIA EMISSIONS TO OCCUR (T0.5) .......................................................................................................................... 99 FIGURE 6.1 MAP OF STUDY SITE SHOWING GROUND ELEVATION, TOPOGRAPHY, SLOPE, SOIL CONDUCTIVITY, GROUNDWATER FLOW DIRECTION, LOCATION OF SUBPLOTS AND OF GROUNDWATER WELLS. ................................................................................................................................. 106 FIGURE 6.2 PLOT SET UP AND RUNOFF COLLECTION PHOTOGRAPH .......... 109 FIGURE 6.3 PHOTOGRAPHS OF RAINFALL SIMULATOR ................................... 111 FIGURE 6.4 NATURAL RAINFALL AND AVERAGE DEPTH OF SIMULATED RAINFALL RECEIVED BY THE PLOTS FOR EACH EVENT ......................... 112 FIGURE 6.5 PHOTO OF THE MEASUREMENT OF VOLUMETRIC WATER CONTENT OF SOIL USING TIME DOMAIN REFLECTROMETRY............... 113 FIGURE 6.6 AVERAGE FLOW-WEIGHTED MEAN CONCENTRATIONS OF DISSOLVED REACTIVE PHOSPHORUS (DRP), DISSOLVED UN-REACTIVE P (DUP) AND PARTICULATE P (PP) COMPRISING TOTAL P (TP) FOR THREE RAINFALL SIMULATION EVENTS, AND MAXIMUM ALLOWABLE CONCENTRATIONS (MAC) IN WATERWAYS. .............................................. 115 FIGURE 6.7 AVERAGE FLOW-WEIGHTED MEAN CONCENTRATIONS OF AMMONIUM NITRATE (NH4-N), NITRITE (NO2-N) AND NITRATE (NO3-N) FOR THREE RAINFALL SIMULATION EVENTS, AND MAXIMUM ALLOWABLE CONCENTRATIONS (MAC) IN WATERWAYS. .................... 117 xxi FIGURE 6.8 AVERAGE RAINFALL INTENSITY, RUNOFF VOLUME, TIME TO RUNOFF AND SOIL VOLUMETRIC WATER CONTENT FOR THE FIRST (RS1), SECOND (RS2) AND THIRD (RS3) RAINFALL EVENTS. ................... 118 FIGURE 7.1 SITE LOCATIONS SHOWN ON MAP OF IRELAND .......................... 127 FIGURE 7.2 SCHEMATIC OF PACKER USED TO ACHIEVE APPROXIMATE BULK DENSITY.................................................................................................... 130 FIGURE 7.3 WATER EXTRACTABLE PHOSPHORUS (WEP) OF INCUBATED SOIL SAMPLES AT EACH SAMPLING TIME (N=3) ....................................... 135 FIGURE 7.4 SOIL TEST P OF INCUBATED SOIL SAMPLES AT EACH SAMPLING TIME (N=3) ............................................................................................................ 136 FIGURE 7.5 PH OF INCUBATED SOIL SAMPLES AT EACH SAMPLING TIME (N=3) ....................................................................................................................... 137 xxii LIST OF TABLES TABLE 2.1 SUMMARY STATISTICS FROM 41 IRISH CATTLE SLURRY SAMPLES (MARTÍNEZ-SULLER ET AL., 2010)................................................... 7 TABLE 2.2 RESULTS OF LABORATORY AND PLOT-SCALE RUNOFF STUDIES EXAMINING THE EFFECT OF LAND APPLICATION OF DAIRY CATTLE SLURRY ON P IN RUNOFF WATER FROM GRASSLANDS ............................ 12 TABLE 2.3 ALTERNATIVE SOIL TEST PHOSPHORUS ANALYSIS METHODS USED AROUND THE WORLD.............................................................................. 14 TABLE 2.4 DILUTION RATES USED TO DETERMINE WEP OF SOIL................... 15 TABLE 2.5 PHOSPHORUS INDEX SYSTEM USED FOR IRISH GRASSLANDS (SCHULTE ET AL, 2010B) ..................................................................................... 15 TABLE 2.6 AVERAGE P INDEX OF SOILS TESTED IN JOHNSTOWN CASTLE FOR THE PERIOD BETWEEN 2004 AND 2006 (MARK PLUNKETT, PERS COM, 2009) .............................................................................................................. 16 TABLE 2.7 PERFORMANCE OF BUFFER STRIPS IN REDUCING TOTAL AND SOLUBLE PHOSPHORUS IN RUNOFF (ADAPTED FROM KAY ET AL., 2009) ................................................................................................................................... 31 TABLE 2.8 REVIEW OF LABORATORY-SCALE STUDIES EXAMINING CHEMICAL AIDED SEPARATION TO REDUCE P IN LIQUID FRACTION OF SEPARATED DAIRY CATTLE SLURRY ............................................................. 37 TABLE 2.9 RESULTS OF LABORATORY AND PLOT-SCALE CHEMICAL AMENDMENTS STUDIES TO DATE ................................................................... 39 TABLE 3.1 CHARACTERISATION OF PSMS AND ALUM USED IN THE AGITATOR TEST (MEAN ± STANDARD DEVIATION) TESTS CARRIED OUT IN TRIPLICATE ...................................................................................................... 47 TABLE 3.2 TABLE SHOWING AMENDMENTS IN ORDER OF EFFECTIVENESS SCORE, BREAKDOWN OF COSTSA, COST/M3 SLURRYB, COST FOR 100 COW FARM, PERCENTAGE REDUCTION IN DRP IN OVERLYING WATER AND WEP OF SLURRY AT 24 H .......................................................................... 49 TABLE 3.3 FEASIBILITY OF AMENDMENTS ........................................................... 54 xxiii TABLE 4.1 STOICHIOMETRIC RATIO AT WHICH THE AMENDMENTS WERE APPLIED AND SLURRY DRY MATTER (DM), PH AND AVERAGE CONCENTRATIONS OF NH4- N, WATER EXTRACTABLE PHOSPHORUS (WEP), TOTAL NITROGEN (TN), TOTAL PHOSPHORUS (TP) AND TOTAL POTASSIUM (TK) (N=3) ........................................................................................ 68 TABLE 4.2 RESULTS FROM CHAPTER 3 AND 4, SHOWING COST OF TREATMENTS AND TOTAL PHOSPHORUS (TP) LOST FROM RUNOFF BOX ................................................................................................................................... 72 TABLE 5.1 DAIRY CATTLE SLURRY AND AMENDED DAIRY CATTLE SLURRY PROPERTIES ........................................................................................................... 89 TABLE 5.2. SUMMARY OF AMENDMENTS USED TO REDUCE AMMONIA EMISSIONS IN PREVIOUS STUDIES .................................................................. 98 TABLE 5.3 SUMMARY OF FEASIBILITY OF AMENDMENTS (ADAPTED FROM CHAPTER 3). MARKS FOR FEASIBILITY AND POLLUTION SWAPPING ARE FROM 1 TO 5. 1 = BEST 5 = WORST......................................................... 102 TABLE 6.1 SOIL PH, MORGAN‘S EXTRACTABLE P, K AND MG, SAND SILT, CLAY FRACTIONS, AND TEXTURAL CLASS OF SOIL USED IN THIS STUDY. THE LOCATION OF THE PIEZOMETERS IS ILLUSTRATED IN FIGURE 6.1 ............................................................................................................ 107 TABLE 6.2 THE AVERAGE SLOPE FOR EACH BLOCK, SOIL PH, WATER EXTRACTABLE PHOSPHORUS (WEP), MORGAN‘S EXTRACTABLE P, POTASSIUM (K), AND MAGNESIUM (MG) BEFORE APPLICATION OF TREATMENTS. ..................................................................................................... 108 TABLE 6.3 SLURRY DM, PH, WATER EXTRACTABLE PHOSPHORUS (WEP), TOTAL NITROGEN (TN), TOTAL PHOSPHORUS (TP) AND TOTAL POTASSIUM (TK) AND AVERAGE CONCENTRATIONS OF NH4- N (N=5) 108 TABLE 7.1 SOIL PHYSICAL AND CHEMICAL PROPERTIES. ...................... 129 TABLE 7.2 SLURRY PROPERTIES .................................................................... 130 TABLE 8.1 SUMMARY OF FEASIBILITY OF AMENDMENTS (ADAPTED FROM CHAPTER 3). MARKS FOR FEASIBILITY, POLLUTION SWAPPING, xxiv INCUBATION STUDY AND PLOT STUDY ARE FROM 1 TO 5. 1 = BEST; 5 = WORST................................................................................................................... 143 xxv Chapter 1 1.1. Introduction Overview In Ireland, agriculture is an important national industry that involves approximately 270,000 people, 6.191 million cattle, 4.257 million sheep, 1.678 million pigs and 10.7 million poultry (CSO, 2006). It utilizes 64% of Ireland‘s land area (Fingleton and Cushion, 1999), of which 91% is devoted to grass, silage and hay, and rough grazing (DAFF, 2008). Livestock production is associated with external inputs of nitrogen (N) and phosphorus (P), which include inorganic and organic fertilizers. Land application of fertilisers followed by a rainfall event can result in incidental losses of P to runoff. In addition, chronic P losses from the soil as a result of a build up in soil test P (STP) can also contribute to losses in other times of the agricultural calendar. Land application of fertilisers also result in N leaching through the soil to surface and ground waters. In practice P is of particular importance as it is the critical nutrient in fresh water systems. In order for Ireland to comply with the requirements of the European Union Water Framework Directive (EU WFD; 2000/60/EC, OJEC, 2000) to achieve at least ‗good status‘ of all surface and groundwater by 2015, programmes of measures (POM) should be in place to prevent such losses. Ireland‘s agricultural POM is the Nitrates Directive (SI 610 of 2010). These measures have addressed the problem by limiting fertiliser application rates and improving manure management. Particular focus has been given to time of application and increasing slurry storage capacity on farms. A possible supplementary mitigation method is the chemical amendment of slurries. However, before chemical amendment of dairy cattle slurry may be considered for implementation in Ireland, there is a need for an extensive study of their use. 1 The aim of this study is to examine the: (1) effectiveness of different amendments to prevent P losses in runoff (2) feasibility of the different amendments to be used on a farm (3) risk of metal release to overland flow and (4) possibility of ‗pollution swapping‘ (defined by Stevens and Quinton (2009) as the increase in one pollutant as a result of a measure introduced to reduce a different pollutant). The present study comprised laboratory and field-scale experiments, which were designed to address knowledge gaps in these areas. For the first time in Ireland, a series of experiments were conducted to examine the possibility of bringing such a supplementary mitigation measure to Irish farms. The specific objectives of this study were: 1. To review existing and emerging P mitigation measures for the control of P losses arising from the land application of dairy cattle slurry to grasslands in Ireland. Following this, the study aimed to select a measure suitable for further study and to identify knowledge gaps which need to be addressed in order for this measure to be considered for implementation at farm scale. 2. To evaluate the effectiveness and feasibility of potential chemical amendments and to use such criteria to select the most suitable amendment for trial at field scale. 3. In parallel to the P mitigation experiments, to examine the effects of pollution swapping, the loss of N chemical species in runoff and gaseous emissions of ammonia (NH3) and greenhouse gases (GHG) to the atmosphere. In addition, this study aims to examine the effect of chemical amendment of dairy cattle of slurry on metal losses in runoff. 4. To examine the effect of chemical amendment of dairy cattle slurry prior to application to soil on long-term soil water extractable phosphorus (WEP) and plant available P. 2 5. To examine the effect of soil type on P solubility in amended slurry applied to soil. 1.2. Procedure A literature review of P loss mitigation technologies with the potential to reduce P losses arising from land application of dairy cattle slurry was undertaken. Chemical amendment of dairy cattle slurry was chosen for further study as chemical amendments have the ability to be quickly implemented, are cost effective and capable of being used in strategic locations for maximum benefit i.e. no capital cost or need to transport slurry long distances. Several knowledge gaps were identified and experiments were designed accordingly. Following this, a novel experiment (an ‗agitator test‘) was used to determine the most suitable amendments for addition to dairy cattle slurry with the aim of reducing P loss in runoff. In this experiment, potential amendments (alum, aluminium chloride, ferric chloride (FeCl2), flyash, flue gas desulphurisation by-product (FGD), lime, polyaluminium chloride hydroxide (PAC) and water treatment residuals (WTR)) were added to slurry before slurry was applied to intact soil cores, which were overlain by water in a 1-L beaker. The overlying water was then stirred to simulate overland flow. The agitator test successfully identified amendments with the potential to reduce dissolved reactive phosphorus (DRP) in overlying water. The most feasible amendments (alum, PAC, FeCl2 and lime) were then examined in a runoff study conducted using laboratory runoff boxes subjected to simulated rainfall applied at an intensity of 11.5 mm h-1 to develop a greater understanding of how chemical amendments affected different forms of P in runoff. It is critical that the potential for ‗pollution swapping‘ is examined when evaluating a potential P mitigating technology such as those examined in this study. In particular, the 3 effects of any proposed treatments on GHG emissions must be examined. To address this, a laboratory chamber experiment was used to examine the effect of chemical amendment of dairy cattle slurry on emissions of NH3, nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2). This allowed for the pollution swapping potential of amendments to be considered in the selection of amendments chosen for field scale study. The most feasible amendments were then examined at micro field plot-scale in Johnstown Castle, Co. Wexford. Twenty five plots, each measuring 0.4 m-wide by 0.9 mlong, were hydraulically isolated before being amended with untreated or chemically amended dairy cattle slurry. Three rainfall simulations were conducted over a period of one month and the surface runoff was collected for half an hour during each event. Finally, a laboratory incubation experiment was conducted to examine (1) the effect of amendments on the long-term plant availability of P in soil and (2) the effect of soil type on stability of reductions in P solubility. Five soils were subjected to six treatments (soil only, slurry only and four chemically amended slurries) and destructively sampled at 0, 3, 6 and 9 months from the start of the experiment. 1.3. Structure of dissertation Chapter 2 reviews the current water quality status in Ireland and the impact of agriculture, particularly dairy cattle slurry, on water quality. Chapter 2 also focuses on Ireland‘s performance in relation to WFD water guidelines, with particular focus on the potential need to explore P mitigating measures for possible implementation if current measures are not sufficient to meet targets. Chapter 3 details the results of the agitator test which was used to evaluate the effectiveness and appropriate application rates for amendments. Chapter 3 also examines the feasibility of amendments and a detailed cost analysis is presented. Chapter 4 describes the results of a laboratory-scale runoff-box study. Chapter 5 details the results of the gas chamber experiments designed to examine the pollution swapping potential of amendments. Chapter 6 details the results of a plot-scale runoff experiment conducted in Johnstown Castle Research Centre. Chapter 7 details the results 4 of the nine-month incubation experiment. Finally, in Chapter 8, conclusions from the study are presented and recommendations for future research work are made. To date, two international peer review papers have been published from this work: Brennan, R.B., Fenton, O., Rodgers, M., Healy, M.G. 2011. Evaluation of chemical amendments to control phosphorus losses from dairy slurry. Soil Use and Management 27: 238-246. Brennan, R.B., Fenton, O., Grant, J., Healy, M.G. 2011. Impact of chemical amendment of dairy cattle slurry on phosphorus, suspended sediment and metal loss to runoff from a grassland soil. Science of the Total Environment 403(23): 5111-5118. A number of international and national conference papers have also been published describing this work. A list of outputs and manuscripts in preparation for submission to international journals are listed in Appendix A. 5 Chapter 2 2.1. Literature review Overview This chapter introduces Irish agriculture, details Ireland‘s current water status under the WFD and comments on the impact which agriculture has on this status. In addition it details where nutrient losses occur from an agriculture system and investigates several mitigation options to prevent such losses. 2.2. Agriculture in Ireland Agriculture accounts for approximately 56% of land use in the Republic of Ireland (CSO, 2009). Each year approximately 29 million tonnes of slurry are produced in Ireland, of which 28% is produced by dairy cattle (Hyde and Carton, 2005). Dairy produce and ingredients amounted to 29% of the value of all agricultural goods, and were estimated at €5.7 billion at producer prices in 2007 (Common Agricultural Policy, 2011). This is expected to increase as worldwide demand for dairy products increases (More, 2009). Dairy cattle slurry may be defined as either ‗the excreta produced by livestock while in a building or yard, or a mixture of such excreta with rainwater, washings or other extraneous material, or any combination of these‘ (Statutory Instrument (SI) 610 of 2010). In Ireland intensive dairy farms (intensively managed farms operate with the objective of maximising output per unit area with high levels of artificial inputs i.e. concentrated feeds and artificial fertiliser). Cattle are typically housed in slatted sheds for between 16 and 18 weeks in the winter months, during which time they are fed silage and concentrates. During this time, the cow manure and urine produced are collected and stored in storage tanks for the winter period. Slurry is rich in nutrients (particularly N, P 6 and potassium (K)), and is generally land applied in the spring and summer months as a fertiliser. An average Irish slurry sample contains 5 kg total nitrogen (TN) m-3 and 0.8 kg total phosphorus (TP) m-3 (SI 610 of 2010). Martínez-Suller et al. (2010) conducted a study of Irish cattle slurry, the results of which are shown in Table 2.1. Slurry is a valuable fertiliser (Lalor and Schulte, 2008a) and it is important that any change in slurry management takes account of the fertiliser value of slurry. Immediately prior to land application, slurry is agitated to improve workability of slurry, to ensure consistency of nutrient concentrations in the slurry and to allow uniform application. After agitation, slurry is land applied using a slurry spreader. Although research has been carried out on alternative spreading techniques such as trailing shoe application (Lalor and Schulte, 2008b) the majority of slurry is applied using a splash plate slurry spreader (Ryan, 2005). Table 2.1 Summary statistics from 41 Irish cattle slurry samples (Martínez-Suller et al., 2010) Variable pH Mean Median Maximum Minimum sd CV (%) 7.3 7.3 7.8 6.8 0.2 2.9 -1 EC (S m ) 1.43 1.6 2.33 4.1 4.9 34 Dry Matter (g kg-1) 62.7 65.1 97.3 5.7 20.7 33 -3 3.43 3.27 7.03 0.36 1.4 41 -3 P (kg m ) 0.56 0.61 1.13 0.04 0.25 44 K (kg m-3) 4.41 4.91 7.75 0.94 2.04 46 N (kg m ) sd = standard deviation; CV = coefficient of variation In concentrated feeding systems such as intensive dairy farms, P inputs into a farm may exceed P outputs (Tunney, 1990). This may give rise to a build-up of STP (Sharpley et al., 2004) as a result of land application of dairy cattle slurry to grassland, which poses a risk to water quality. In addition, losses during and after land spreading also pose risk to a waterbody. Therefore, there is a need for the development of management practices, which allow maximum production with minimum negative environmental impacts i.e. livestock numbers will not reduce. 7 2.3. Legislation and compliance The EU WFD (OJEC, 2000) aims to achieve at least ―good ecological status‖ in all waterbodies by 2015 through the implementation of POM by 2012. In Ireland the agricultural POM is the Nitrates Directive (EEC, 1991). The Nitrates Directive has been implemented since 2009. Huge investment in farm infrastructure has resulted in reduced P losses from agricultural point sources. Guidelines for farm management provide best management practice for slurry and inorganic fertiliser application to grassland to minimize diffuse P losses and increased STP. An Agricultural Catchments Programme has been established to evaluate catchment-scale evaluation of their effectiveness (Schulte et al., 2010a). The statutory instrument which governs agricultural practice in Ireland is The European Communities (Good Agricultural Practice for Protection of Waters) Regulations 2010 (SI 610 of 2010). This places a responsibility on the individual farmer and the public authority to adhere to the conditions set out within the Nitrates Directive (EEC, 1991) and the WFD. Individual farmers are required to maintain records of activities with regard to soil testing, storage capacity, nutrient management, minimum storage period, and periods when application to land is prohibited. Land spreading of slurry is forbidden if (1) heavy rainfall is forecast within the 48 h of application (2) land is frozen or snow-covered (3) the land slopes steeply towards a river or stream, or (4) slurry is to be applied directly to bedrock (SI 610 of 2010). In addition to the POM, the WFD recommends research and development of new pollution mitigation measures to achieve the 2015 target. 2.4. Current water quality status in Ireland The Irish Environment Protection Agency (EPA) has reported findings based on analyses of 2,985 sampling locations on 1,151 rivers between 2007 and 2009 (McGarrigle et al., 2011). Approximately 68.9% of Ireland‘s rivers were unpolluted, 20.7% were slightly polluted, 10% were moderately polluted and 0.4% were seriously polluted (McGarrigle et al., 2011). When these rivers were assessed for ecological status, based on the various 8 biological and physico-chemical quality elements, only 52% of water bodies achieved ‗good status‘. Diffuse losses (including those from agricultural and other sources) were responsible for approximately half of the polluted sites monitored. Similarly, using the traditional method of assessment, 92.1% of lakes were in an un-enriched, oligotropic status - similar to that observed for 2004-2006 period. However, according to the requirements of the WFD, 47.5% were of ‗good status‘. The report also examined measurements from 211 groundwater monitoring stations: 84.7% of ground water bodies were in good status, while 15.3% were in poor status. Figure 2.1 shows the decline in poor status for groundwater. This reduction was attributed to increased rainfall, reductions in inorganic fertiliser usage, improved organic fertiliser storage, and implementation restrictions on timing of land applications. The McGarrigle et al. (2011) report concluded that substantial measures will be required for Ireland to comply with the objectives of the WFD. Figure 2.1 Number of ground water monitoring sites with phosphate concentrations from 1995 to 2009 (McGarrigle et al., 2011) 9 2.5. Impact of agriculture on water quality Agricultural activities are thought to be responsible for approximately 38% of slightly polluted rivers, 23% of moderately polluted, and 29% seriously polluted rivers (McGarrigle et al., 2011). Figure 2.2 shows the number of reported fish kills attributed to agriculture from 1971 to 2009 (McGarrigle et al., 2011). The impact of agriculture on water has reduced steadily since 1997; however, further reductions are required to meet the requirements of the WFD (McGarrigle et al., 2011). It is important to note that research constantly challenges the accuracy of the estimated contribution which agriculture makes to pollution of Irish rivers. This contribution is currently being examined as part of the Agricultural Catchments Programme. McGarrigle et al. (2011) found that 0.3% of the waterbodies in the Republic of Ireland were of ‗poor status‘ due to nitrate (NO3), compared to 13.3% due to P. Therefore, in Ireland future mitigation measures must focus on P losses with emphasis on diffuse losses from agriculture. Figure 2.2 Number of reported fish kills attributed to agriculture, industry, local authority, other and unknown sources (McGarrigle et al., 2011) 10 2.6. Nutrients loss and pathways during land application of dairy slurry Throughout the EU and U.S.A. agricultural management has been identified as a landscape pressure impacting on water quality (Sharpley et al., 2001a, b; Schulte et al, 2006; Stark and Richards, 2008; Kronvang et al., 2009). Transfers of N and P from agriculture to water can lead to eutrophication and may occur in three ways: (1) as point source losses from farmyards because of excessive rates of soiled water application through the use of rotational irrigators; (2) as diffuse losses from soil, which are related to soil P and N concentrations in excess of crop requirements; and 3) as incidental losses from direct losses of fertilizer or manures to water during slurry application, or where a rainfall event occurs immediately after application (Preedy et al., 2001). Diffuse P losses, specifically incidental and chronic P losses arising from land application of dairy cattle slurry to grasslands in Ireland, are thus the focus of this study. 2.7. Phosphorus Phosphorus is an essential nutrient for plant growth, and land application of organic and inorganic P fertiliser is needed to maintain profitable animal and crop production (Sharpley et al., 2003). In concentrated feeding systems such as intensive dairy farms, P inputs into a farm can exceed P outputs (Tunney, 1990). This can give rise to high STP soils which pose a risk to water quality. Phosphorus is also of particular importance in fresh water systems as it is the limiting nutrient for the occurrence of eutrophication (Correll, 1998; Sharpley and Tunney, 2000). Transfers of P from agriculture to water can lead to eutrophication of a waterbody (Carpenter et al., 1998). Land application of dairy slurry can result in incidental and chronic P losses to a waterbody (Buda et al., 2009). Incidental P losses take place when a rainfall event occurs shortly after slurry application and before slurry infiltrates the soil, while chronic P losses is a long-term loss of P from soil as a result of a build-up in STP caused by application of inorganic fertilisers and manure (Buda et al., 2009). Table 2.2 shows a summary of the results of laboratory and plot-scale runoff studies examining the effect of land application of dairy cattle slurry on DRP and TP concentrations in runoff water from grasslands. These results show the 11 importance of timing of rainfall event following slurry application. In addition this table identifies a need to examine runoff from slurry at lower more realistic rainfall intensities. Table 2.2 Results of laboratory and plot-scale runoff studies examining the effect of land application of dairy cattle slurry on P in runoff water from grasslands Reference Type Size Intensity WEP TP DRP TP Time after ------ slurry ------ ----- runoff ------ application m2 mm h-1 kg ha-1 kg ha-1 mg L-1 mg L-1 Days 1 x 0.2 70 14 50 3.2 6.35 3 1.85 3.2 10 1.5 2 24 43 0.35 130a 122 10.9 3 10.3 48 2 3.1 5 5 3.6 4.1 9 7 7* Runoff mm Kleinman and Sharpley (2003) Smith et al. (2001c) Plot 2 x 15 Natural Elliott et al. (2005) Box 1 x 0.2 71 Hanrahan et al. (2009) Box 1 x 0.2 30 Preedy et al. (2001) a Box Plot 3 x 10 41.6 30 Natural 29 5.4 48 Runoff collected for duration of study 2.7.1. Phosphorus in soil The soil P cycle is shown in Figure 2.3. Phosphorus exists in organic and inorganic forms, and may be simplified into three types of P: (1) slow inorganic P (2) rapid cycling organic and inorganic P and (3) slow organic P. This is a dynamic equilibrium system and transformations between forms occur continuously (Sharpley, 1995). The availability of P to plants and water in contact with soil is controlled by chemical processes within the soil (Sharpley, 1995). 2.7.2. Methods used to determine risk of P loss to water The slow inorganic pool provides P to replenish the solution P pool, and comprises inorganic P attached to small particles or elements, such as aluminium (Al) and calcium (Ca), and organic P that is easily mineralised. The rapid cycling of organic and inorganic P makes up a small proportion of total P in the soil, and is the most available to plants and to overland and subsurface flow. It is constantly being depleted and replenished from 12 slow organic and inorganic P pools. Microbial P has an important role in short-term dynamics of organic P transformations and has a significant effect on P availability. Inorganic manure applications increase microbial activity in the soil, which leads to increased P availability. The slow organic pool contains compounds that are insoluble and organic P, which is less liable to mineralisation. Slow inorganic Primary P minerals (Al, Fe and Ca minerals) Secondary P minerals (Al, Fe and Ca minerals) Occluded P Rapid cycling organic and inorganic Fertiliser Slow organic Animal manure Plants Plant residues Solution P Microbial P Labile and moderately labile inorganic P (amorphous sesquioxides and some crystalline Al and Fe) Chemically and physically protected organic P (humic acid) Labile and moderately labile organic P (phosphollpids inositois, fulvic acid) Figure 2.3 The soil P cycle: its components and measurable fractions (Steward and Sharpley, 1987) Tests were initially developed to measure availability of P for agronomic purposes, with loss of P to water from soil not considered a priority. Studies found that P losses from soil were a major water quality concern (Sharpley and Rekolainen, 1997) and water quality became the focus of soil P testing. Commercial analysis is focused on testing methods which measure plant available P. However, researchers have found a relationship between STP and DRP in surface runoff (Regan et al, 2010; Little et al, 2007). Soil test P has been shown to be the main factor influencing P concentrations in runoff if no fertilisers have recently been applied (DeLaune et al., 2004; Dougherty et al., 2008). Different tests for the determination of STP have been adopted internationally depending on soil types and tradition (Table 2.3). Studies have shown that the STP in the upper 20 mm of grassland soils tends to be higher than for the equivalent depth in tillage soils receiving the same manure (Ahuja et al., 13 1981). This is due to the absence of deep tilling, which ploughs the nutrients into the soil (Andraski et al., 2003; Sharpley, 2003). It has also been shown that the use of 100 mm sampling depth (used to determine the Morgan‘s P of the soil) underestimates P loss risk from soils and grasslands in particular (Humphreys et al.,1999). Mulqueen et al. (2004) recommended reducing the sampling depth to improve environmental risk prediction; however, Schroeder et al. (2004) reported that sample depth (2, 5 and 10 cm) had no effect on the relationship between soil P concentration and P concentration in runoff. Daly and Casey (2005) conducted an extensive review of sampling depth and concluded that the sampling depth of 100 mm was best. This was primarily due to the huge variability with smaller sampling depths. Torbert et al (2002) reported greater variation when sampling soil to a depth of 25 mm compared to 100 and 150 mm. It was suggested that this could be a result of a combination of an increased sensitivity of the testing procedure to ‗hot spots‘ of manure in the field and difficulty in obtaining a consistent sample. Table 2.3 Alternative soil test phosphorus analysis methods used around the world Method Bray 1 (Bray and Kurtz, 1945) Soil Acidic to slightly alkaline (<6 to 7.2) Countries UK and Australia Mehlich 1 and Mehlich 3 (Mehlich 1984) Olsen P (Olsen et al., 1954) Acidic to slightly alkaline (<6 to 7.2) Europe and U.S.A. Slightly acidic to alkaline (6.0 to >7.2 UK Morgan‘s P (Morgan, 1941) Acidic to slightly alkaline (<6 to 7.2) Ireland The WEP test was developed to measure the environmental risk posed by P in any soil. The WEP test is also used to determine the risk of P loss from manures applied to grassland. In this test, soil is mixed with water to replicate soil and water interactions and to estimate dissolved P losses from soil. The general procedure is to weigh accurately a mass of soil into a known volume of distilled water in an un-reactive container and to shake for a time between 30 and 60 min. After shaking, the solution is centrifuged and passed through a 0.45 μm filter. Different dilution ratios commonly used are shown in Table 2.4. 14 Table 2.4 Dilution rates used to determine WEP of soil Author Regan et al. (2010) Pote et al. (2003) McDowell and Sharpley (2001) Dilution ratio 1:80 1:25 1:5 1:100 Type of study Runoff box Field Incubation Schulte et al. (2010b) showed that it may take many years for elevated STP concentrations to be reduced to optimum levels to reduce risk to water quality. In Ireland, a P index system is used to quantify risk of P loss from a soil (Table 2.5). There are 4 categories, with Index 1 representing a P deficient soil and Index 4 (STP > 8 mg P L -1) representing a grassland soil which presents a risk to water quality (Tunney, 2000). While the onset of reductions in excessive STP levels may be observed within five years, this reduction is a slow process and it may take up to 20 years for P index 4 soils to complete the reduction to the boundary Index 3 (a STP of between 5.1 and 8 mg P L-1) (Schulte et al., 2010b). Table 2.5 Phosphorus Index system used for Irish grasslands (Schulte et al, 2010b) Soil P index Morgan‘s soil P range for Interpretation -1 grassland soils (mg L ) 1 0.0-3.0 Soil is P deficient; build-up of soil P required. Insignificant risk of P loss to water 2 3.1-5.0 Low soil P status: build-up of soil P is required for productive agriculture. Very low risk of P loss to water 3 5.1-8.0 Target soil P status: only maintenance rates of P required. Low risk of P loss to water 4 >8.0 Excess soil P status: no agronomic response to P applications. Risk of P loss to water increases within this index The STP levels and the difference between available and total P for Irish soils can mostly be explained by land use, rock and soil type. Table 2.6 shows the average percentage of soils in each P index for all soil samples tested in Teagasc, Johnstown Castle between 2004 and 2006 (Mark Plunkett pers com, 2009). Phosphorus losses from agricultural soils 15 are generally a result of an increase in STP caused by long-term applications of P fertilisers (Frossard et al., 2000). Table 2.6 Average P index of soils tested in Johnstown castle for the period between 2004 and 2006 (Mark Plunkett, pers com, 2009) Soil P index 1 STP mg L-1 0.0-3.0 Grassland % 15 Tillage % 15 2 3.1-6.0 25 30 3 6.1-10.0 27 23 4 >10.0 33 In 2008 the Phosphorus Index system was amended (Lalor and Coulter, 2008). 2.8. 32 Nitrogen Nitrogen is the most abundant gas in the atmosphere and can exist in various compounds. The process by which N is transformed to its various forms is called the N cycle (Figure 2.4) (Ketterings et al., 2011). The major conversion processes which make up the N cycle are: N fixation, mineralisation, nitrification, denitrification, ammonia volatilisation, and immobilisation. Biological N fixation is a process by which soil bacteria and plant roots interact to convert nitrogen gas (N2) in the atmosphere to proteins. In industrial production, the Haber-Bosch process is used to combine N2 and hydrogen gas (H2) with a catalyst under intense heat and pressure for form NH3, which is then used to make fertiliser. Biological N fixation requires plant energy so if available N exists, the plant will use this before biological fixation takes place (Ketterings et al., 2011). Mineralisation is the process that converts organic N in soil, manure and decaying plants to inorganic forms (ammonium (NH4) and NH3). Nitrification occurs when microbes use enzymes to convert NH4 to nitrite (NO2) and then NO3 to obtain energy. Warm, moist and aerated conditions favour nitrification. 16 Figure 2.4 Schematic of the soil N cycle (Ketterings et al., 2011) Step 1: NH4 → NO2 (2.1) Step 2: NO2- → NO3 (2.2) Denitrification is the process by which N is lost from the soil through the conversion of NO3 to various gaseous forms of N. Significantly, this reaction can produce N2O, which is a potent GHG. Therefore, treatments such as chemical amendment of dairy cattle slurry 17 which could potentially change the N cycle, and could impact N2O release. Wet, poorly drained soil favours the occurrence of denitrification. NO3 → NO2 → NO → N2O → N2 (2.3) Ammonia volatilisation is the production and release of NH3 from NH4 on the soil surface. Ammonia losses are greatest in soils with high pH and in dry, warm and windy weather (Ketterings et al., 2011). Immediately following land application of dairy cattle slurry, there is an initial peak in NH3 emissions and it is estimated that 60% of ammonical nitrogen (NH4-N) applied is lost during land spreading of cattle slurry (Hyde et al., 2003). There exists a state of equilibrium between the NH3 in the slurry/soil interface and the NH3 in the air immediately above the soil surface (Génermont and Cellier, 1997). The pH of the slurry/soil combination has also been observed to affect the rate of NH3 volatilisation. Depending on the pH, NH4-N can occur as NH3 gas or the ammonium ion (NH4+) (Gay and Knowlton, 2005). The relationship between NH4 and NH3 as a function of pH is shown in Figure 2.5. Figure 2.5 Relationship between the ammonia/ammonium (NH3/NH4+) ratio and pH (Gay and Knowlton, 2005) 18 Immobilisation is the reverse of mineralisation and occurs when microbes temporarily bind available N in soil biomass (Ketterings et al., 2011). Nitrogen can be lost to surface ground waters (Stark and Richards, 2008) and to the atmosphere in gaseous form (Ketterings et al., 2011). On a farm, N losses are spatial in nature and occur from the entire farm, while P losses can be due to small portion of farm (Poinke et al., 2000) called Critical Source Areas (CSAs). Therefore, measures to reduce P loss that are applied through a farm may have a greater effect on N loss than P loss. 2.9. Loss of soluble and particulate nutrients in runoff Nutrients can be lost to a surface waterbody in particulate and soluble forms. Suspended Sediment (SS) loss contributes to particulate phosphorus (PP) in runoff from tillage soils (Regan et al., 2010); however, in grasslands most P loss is in dissolved form with Total Dissolved Phosphorus (TDP) and DRP making up 69% and 60% of TP load in surface runoff (Haygarth et al., 1998). Incidental SS losses following slurry application can result in high concentrations of SS in runoff, resulting in increased PP losses (Preedy et al., 2001). This PP can be mineralised and become available to algae (Sharpley, 1993). Withers et al. (2003) examined the results of a number of studies examining P losses following land application of dairy cattle slurry at different rates and under different climatic conditions (Smith et al., 2001c; Withers et al., 2001; Withers and Bailey, 2003) and found that incidental P losses can account for between 50 and 90% of P losses from land to water. These variations are due to difference site and climatic conditions. 2.9.1. Soluble nutrient loss The processes involved in transfer of soluble P from soil or slurry to water are similar. Phosphorus release occurs as a result of the processes of precipitation-dissolution and adsorption-desorption (Frossard et al., 2000). Soluble P losses dominate P loss from grasslands (Sharpley et al., 1992). Kleinman et al. (2006) found that concentration of water soluble P in manure was strongly related to DRP in runoff from three soils examined. 19 Nitrate is the form of N most available to plants and to runoff, and makes up to approximately 2% of soil N at any time (Ryan et al., 2008). This NO3 is constantly replenished if N is lost, and is very soluble and easily taken up from soil by runoff (Ryan et al., 2008). Although P is the limiting nutrient in freshwater systems (Correll, 1998), N losses also pose a significant risk to water quality (Johnes et al., 2007; Vitousek et al., 2009). It is recommended that slurry should be applied in spring time to maximise N efficiency (Lalor and Schulte, 2008) and to reduce risk of leaching of N to groundwater, as less NO3 is lost when plants are growing and fertiliser is applied at rates corresponding to the requirements of the crop being grown (Power and Schepers, 1989). In a lysimeter study which examined NO3 losses from five different soil types, Ryan and Fanning (1996) found that winter applications of pig and dairy cattle slurry resulted in higher NO3 losses than spring applications. This is most likely due to uptake of NO3 by plants during the spring when plants are growing. 2.9.2. Particulate nutrient loss Erosion of soil or surface runoff of land applied slurry by water occurs predominantly as a result of the processes of detachment (caused by the impact of the raindrops on the soil/slurry surface) or by erosion mechanisms such as entrainment and re-entrainment. As the processes of soil erosion and runoff of land applied slurry are analogous to one another, the fundamental mechanisms of surface runoff of land applied slurry will be discussed in the context of soil erosion. Detachment of the soil particles from the soil surface is due to the impact of the raindrops falling under gravity on the ground (Figure 2.6). The cohesive bonds between the soil particles are brittle, and, once broken, the cohesive strength of the soil is lost. Provided the infiltration rate is greater than the rainfall rate, the soil particles will return to the soil surface. If rainwater accumulates on the surface, erosion can occur and the detachment process will continue. The risk of SS and P loss to surface waters in a rainfall event decreases dramatically with an increase in time from slurry application to start of the rainfall event (Smith et al., 2007; Allen and Mallarino, 2008; Hanrahan et al., 2009). 20 Figure 2.6 Detachment of soil particles in a rainfall event (Rose, 2004) The potential for P loss peaks and then declines over time, as P applied in slurry interacts with the soil (Edwards and Daniel, 1993). The processes for slurry SS loss are similar to soil erosion processes. Hanrahan et al. (2009) reported that TP and DRP concentrations were reduced by 89 and 65%, respectively, by delaying rainfall from 2 to 5 d after dairy cattle slurry application. In addition, McDowell and Sharpley (2002a) found that flow path length had a significant effect on P fractions in runoff following land application of dairy swine slurry. Therefore, when examining the effect of changes in slurry management, these factors must be taken into consideration. Rose (2004) considered the difference between the rate of detachment and the rate of sediment deposition to be responsible for the initial development of sediment runoff in surface water. As P is adsorbed to sediment (Torbert et al., 2002), the settling velocity of eroded soil particles is of critical importance. Smaller particles will take much longer to settle and have the potential to travel greater distances than larger particles in the same 21 conditions (Figure 2.7). The distance which these particles can travel is determined based on Stokes law (Batchelor, 1967). Figure 2.7 Rate of sediment deposition in surface runoff (Rose, 2004) The gradual formation of a surface seal under prolonged rainfall and submergence may cause reduced infiltration rates into the soil and, consequently, may induce increased erosion in some soils. This phenomenon occurs when the impact of the falling rain damages the structure of the soil so that the permeability of the soil surface is reduced or when rain falls on damaged clay soils with very low permeability. This theory suggests that the soil particles are held together in bundles or aggregates. The action of the rain falling can break these bundles apart and, in some cases, may cause the pores on the soil surface to seal (Rose, 2004). Detachment is the dominant process responsible for sediment erosion in the early stages of a rainfall event (Rose et al., 1983). As the runoff event increases in magnitude, the rainwater can no longer infiltrate the soil surface and overland flow occurs. This phenomenon is also known as capping or infiltration excess (Horton, 1933). Entrainment is the process which involves the surface runoff eroding the soil particles (Figure 2.8). The erosion processes for slurry are similar to soil. 22 Figure 2.8 Entrainment and re-entrainment of sediment (Rose, 2004). The ability of flowing water to erode sediment is related to the stream power, Ω, which is a function of shear stress and the velocity of the surface runoff (Rose, 2004). Once Ω exceeds a threshold value, Ωo, sediment is eroded. Detachment processes are less significant in deep surface flow. However, rain falling on shallow water will increase turbulence and liberate particles. Particles which are put into suspension after entrainment are then deposited according to their settling velocity. Over time, these particles accumulate and begin to rebuild the eroded soil surface. These particles have insufficient time to gain cohesive strength and are more easily eroded than the original deposited sediment. This erosion process is known as re-entrainment. Re-entrainment moves the particles in the general direction of flow by saltation (Figure 2.8). The processes by slurry particles are moved in surface water are similar. 23 2.10. Gaseous emissions and the importance of considering pollution swapping when selecting a P mitigation measure Agricultural activities contribute to the production of NH3 and GHG such as CO2, N2O and CH4. In particular, land application of dairy slurry can result in the release of NH3 (Amon et al., 2006), N2O (Ellis et al., 1998), and CH4 (Chadwick and Pain, 1997). It is critical that the potential for pollution swapping is examined when evaluating a potential technology. In particular, the effects of any proposed treatments on GHG emissions must be examined. Under the 1997 Kyoto Protocol of the United Nations Framework Convention on Climate Change (UN, 1998), participating nations agreed to publish national inventories of anthropogenic emissions of several GHG and to reduce future emissions below 1990 levels. In Ireland, agricultural activities were responsible for approximately 26% of total GHG emissions in 2008 (McGettigan et al., 2010) and account for virtually all NH3 emissions, with animal manure alone responsible for 92% of NH3 emissions (EPA, 2010). While NH3 is not a GHG, it contributes to acidification of soils, atmospheric pollution, and the eutrophication of surface and ground water systems (Goulding et al., 1998). An estimated 5% of global N2O emissions results from the conversion of NH3 into N2O in the atmosphere (Ferm, 1998). 2.11. Present and emerging P mitigation measures The general consensus held by researchers in Ireland is that Ireland will not meet its water quality targets by 2015 (Schulte et al., 2010b; McGarrigle et al., 2011). This failure to achieve the required improvements in water quality status is a common problem being faced throughout Europe and in the US. It is largely accepted that supplementary measures, in particular the development of P mitigating technologies, will be critical to develop short-term farm management practices which will reduce nutrient losses to waterbodies (Buda et al., 2010). These mitigation methods, together with best management practices which are already in place, will enable the achievement of water quality requirements in shorter time period. This will allow for the development of longterm, sustainable management practices to minimise risk of P loss to water. 24 In Ireland, attempts to reduce diffuse P loss from agriculture have focused on increasing nutrient efficiency and improving slurry management strategies. To address the time lag between implementation of these strategies and reduction of STP to the boundary index 3 in high P-index farms (Table 2.6), short-term P mitigation technologies are required. Current guidelines state that farmers may only apply dairy cattle slurry to high STP soil in the absence of low STP soil. On such farms, treatment of dairy cattle may be considered for use in tandem with existing management practice to reduce the solubility of P during this ‗time lag‘ period. Mitigation methods to reduce incidental P losses include incorporating slurry into soil immediately after land application (Tabbara, 2003), increasing length of buffer zones between slurry application areas and drains and streams (Mayer et al, 2006), enhanced buffers strips (Uusi-Kämppä et al., 2010), timing of slurry application (Hanrahan et al., 2009), chemical amendment (Dao and Daniel, 2002; Dou et al., 2003) and diet manipulation (O‘Rourke et al., 2010). The risk of P loss from slurry is strongly related to the WEP in the slurry (Dou et al., 2003) and amendments which reduce P solubility should reduce P loss to runoff. In this section, current management practices, along with new technologies, to treat dairy cattle slurry and to mitigate P losses from land application of dairy cattle slurry are discussed. 2.11.1. Constructed wetlands To date, free-water surface (FWS) Constructed Wetlands (CWs) (reed beds) are the most widely used, low-cost and low-maintenance alternative to land spreading of dairy wastewaters in Ireland. Constructed wetlands provide an environment for the physical/physico-chemical retention and biological reduction of organic matter (OM) and nutrients (Knight et al., 2000). Depending on the organic loading and retention time (Karpiscak et al., 1999), constructed wetlands can have a significant nutrient removal capacity. However, due to the effect of varying temperatures, the treatment efficiency of these systems tends to vary throughout the year (Healy and Cawley, 2002). Constructed wetlands may be planted with plants found in natural wetlands and lined with soil to trap nutrients and solids from wastewaters. They may be used to treat runoff 25 from intensively farmed soils in close proximity to sensitive water bodies (Tanner et al., 2005), or alternatively, to treat wastewaters before water is land applied to reduce potential for pollution (Healy et al., 2007). There is a long history of use of CWs to treat municipal wastewaters and they have more recently been adopted to treat dairy waste water and screened dairy slurry (the liquid portion of dairy cattle slurry following separation) (Healy et al., 2007). Guidelines for the design loading of surface-flow wetlands (Healy et al., 2007) recommend an area loading rate of approximately 5 g of 5-day biological oxygen demand (BOD5) m-2d-1. Although CWs have been shown to be very effective achieving good reductions in municipal and dilute dairy waste waters (soiled dairy water etc), the high solids content and the high nutrient concentrations of agricultural slurries make them difficult to treat. New Zealand guidelines for the disposal of farm dairy wastewaters (Tanner and Kloosterman, 1997) recommended that an FWS CWs should only succeed two waste stabilization ponds (an anaerobic and an aerobic pond, respectively) before entering the wetland with an organic loading rate not exceeding 3 g BOD5 m-2 d-1. The anaerobic pond reduces the BOD5 and SS, and the aerobic pond carries out further biological reductions. Mantovi et al. (2003) suggests that the milking parlour should be designed to allow parlour washings and washings from the holding room to be separated, so as the wetland only treats the effluent of lower organic and nutrient content. The removal of NH4-N from strong waste waters is generally inadequate in most CWs (Sun et al., 2005; Toet et al., 2005). Inorganic nitrogen removal is also often unsatisfactory (Luederitz et al., 2001) and in Europe, average percentage removal of NH4-N during long-term operation is approximately 35%, with a maximum of 50% (Verhoeven and Meuleman, 1999). The ability of CWs to retain P is dependent on the P loading rate, the media type, vegetation, and duration of operation (Healy et al., 2007), although changes in pH and redox potential could also release P from the system. Healy et al. (2007) reported that between 65 and 95% of P may be removed at loading rates of less than 5 g TP m-2 yr-1. 26 Phosphorus is removed through short-term or long-term storage, with most removal often occurring near the inlet initially, before extending throughout the wetland over time as those sites become P-saturated (Jamieson et al., 2002). Uptake by bacteria, algae and duckweed (Lemma spp.), and macrophytes provides an initial removal mechanism. However, this is only a short-term P storage as 35 to 75% of P stored is eventually released back into the water upon dieback of algae and microbes, as well as plant residues. The only long-term P storage in the wetland is via peat accumulation and substrate fixation, the efficiency of which is a function of the loading rate and the amount of native iron (Fe), Ca, Al, and OM in the substrate. Henry et al. (2003) reported reductions of total dissolved solids (TDS), NH4-N, TN, and TP were 58%, 83%, 90%, and 84%, respectively, in the first 3 years of operation. These were above the national averages for CWs. However, these results indicate that CWs can be effective when properly managed. Although there is much evidence to support use of CWs, the P mitigating processes and long-term viability of CWs for P control are not sufficiently understood to pursue CWs as a potential management decision to control short-term P surplus. The also perform poorly when it is raining and are susceptible to incidental P loss during storm events. 2.11.2. Anaerobic digestion Digestion of organic wastes results in the production of slurry with lower pollution potential and which is more suitable for use as a fertiliser while producing renewable energy (Singh et al., 2010a). Anaerobic digestion (AD) is now seen as the best manure management practice, as it offers the opportunity to reduce gaseous emissions from manure, increase N availability, produce biogas and reduce GHG emissions (HolmNielsen et al., 2009; Masse et al, 2011). Although AD reduces WEP of slurry without reducing plant availability of P (Moller and Stinner, 2009), the main benefit of AD in terms of P mitigation is that the digested slurry can be separated and the solid fraction exported off-farm for use as a soil conditioner, or further processed into a granular organic fertiliser, or a combustible fuel which has a commercial value. Anaerobic digestion reduces gaseous losses from slurry (Amon et al., 2006; Clemens et al., 2006) 27 and increases N availability in slurry (Moller et al., 2008). Amon et al. (2006) reported that AD reduced N2O losses from dairy cattle slurry by approximately 28% compared to a slurry-control. Anon et al. (2006) also reported that CH4 losses following land application of digested dairy cattle are lower and there are no adverse effects on NH3 emissions compared to untreated dairy cattle slurry (Amon et al., 2006; Clemens et al., 2006). In addition, AD can lower the odour from farm slurries by up to 80% (Pain et al., 1990), lower survival of pathogens in the slurry (Masse et al, 2010; Cote et al., 2006), and kill many weed seeds, reducing need for herbicides (Frost and Gilkinson, 2010). There are extensive AD plants in mainland Europe; however, there are only pilot-scale plants in Ireland (Anon, 2011). Although AD is not currently considered a P management option, Gungor and Karthikeyan (2008) reported that AD decreases water soluble P faction by between 22 and 47% compared to undigested slurry. Although the advantages of AD are immense, there are some difficulties which have restricted their adoption in Ireland. The main barriers to their use are the high capital cost necessary to establish them, the low dry matter (DM) content of slurry on many dairy farms, the energy requirement to maintain temperatures sufficient for the digester to operate, and a long hydraulic retention time. This means that a large AD reactor is necessary for high volumes of slurry (Frost and Gilkinson, 2010). Moller et al. (2007) examined the feasibility of separating slurry prior to AD and recommended that preseparation may increase yield, but the feasibility depends on the cost of separation and transportation of slurry from farm to AD plant. Although AD is the most environmentally sustainable means of treating slurry in the long-term, it is unlikely that AD can be implemented specifically to mitigate P losses in sufficient time to meet requirements of the WFD. Many German farmers make a living producing biogas from such operations; however, their government provides financial supports for such enterprise (Anon, 2011). In the long-term, with improvements in technology and with the support of government initiatives, AD may become a management practice in Ireland. 28 2.11.3. Biochar Biochar is produced when biomass is burnt in the absence of oxygen at temperatures <700°C (Lehmann and Joseph, 2009). There is growing acceptance that biochar may play a part in reducing GHG emissions from agriculture (Winsley, 2007). There are two biochar P mitigation management systems currently being examined for the treatment of dairy cattle slurry: (1) slurry can undergo pyrolysis and be converted to a biochar, which can be applied to soils as a soil conditioner and fertiliser and to reduce losses of metals from soils (Cao and Harris, 2010) and (2) biochar produced from another biomass source can be used to sequester P and then land applied in another location (Streubel et al., 2010). These technologies have the potential for use as part of sustainable manure management to allow transport of biochar produced from slurry, or biochar enriched with nutrients, to soils with low STP. Biochar has a much lower volume than slurry used to produce it and would be much more attractive as a fertiliser and soil conditioner to a wide range of uses not limited to agriculture. Land application of biochar can restore fertility in degraded soils (Novak et al., 2010), improve health of the soil (O‘Neill et al., 2009; Van Zwieten et al., 2010), reduce nutrient leaching (Singh et al., 2010b), reduce GHG losses (Gaunt and Lehmann, 2008; Rogovska et al., 2011) and improve fertiliser efficiency in some soils (Van Zwieten et al., 2010). Streubel et al. (2010) investigated the potential for using biochar produced from pyrolysis of AD sludge to sequester P from dairy lagoons and found that 50% reduction of soluble P in dairy slurry lagoon was achieved while the plant available P in the biochar increased from 4 to 45 mg kg-1 Olsen P. This system allows the nutrients to be trapped and transported to areas with low P soil where they can be used a soil conditioner and fertiliser. Although there is excellent potential for GHG emission reduction (Gaunt and Lehmann, 2008) and potential to reduce P loss from agriculture by transporting saleable product from areas with P surplus, this technology is not developed sufficiently for widespread implementation. There are high capital costs and these systems would need to 29 be validated at farm-scale before being recommended for use in Ireland. The low DM of dairy cattle slurry results in a very high cost of drying slurry and this is one of the main barriers to the production of biochar from slurry (Xinmin Zhan pers com, 2011). Systems using biochar to sorb P from slurry lagoons are not as likely to be attractive to farmers in Europe as in the U.S.A., as slurry lagoons are not as common in Europe. In addition, the risk of pollution swapping associated with slurry lagoons is a problem. The main barrier to use of biochar technology is that there is no legislation in place regarding of biochar for use by agriculture and before biochar can be used as an amendment for soils, standards need to be established (Kwapinski et al., 2010). 2.11.4. Buffer strips and enhanced buffer strips Buffer strips have been implemented to reduce P losses from waters entering waterways (Hoffmann et al., 2009). Buffer-strips are particularly effective at reducing PP and current best farming practice stipulates a 2.5 m buffer-strip between edges of slurry application and a stream or drain. This is a natural buffer-strip which acts to reduce risk of P loss to surface waters. Studies have reported conflicting results (Table 2.7). The consensus is that buffer-strips are not very effective at trapping DRP (Watts and Torbert, 2009) and are generally more effective in reducing PP losses (Hoffmann et al., 2009). They are a cost effective TP and PP mitigation method and offer an attractive means of treating runoff from high STP soils. However, they are not always effective in storm events. Many researchers have examined the potential to enhance DRP sorbing potential of buffer strips using amendments (Dayton and Basta, 2005; Uusi-Kämppä et al., 2010). Uusi-Kämppä et al. (2010) examined the potential for use of amendments in buffer strips to increase P retention and found that, while gypsum and CaCO3 did not change DRP and TP loss to runoff during simulated runoff events, Fe-gypsum and granulated ferric sulphate increased DRP and TP retention between 74-85 and 47 to 64%, respectively. Dayton and Basta (2005) enhanced a buffer strip down-slope of soil receiving poultry litter using WTRs (20 Mg ha-1 WTR). This resulted in a reduction in DRP in runoff by between 67 and 86% compared to the buffer strip without any WTR incorporated. Watts 30 and Torbert (2009) applied gypsum at 0, 1, 3.2 and 5.6 Mg ha-1 to a 1.52 m-wide bufferstrip down-slope of a soil receiving poultry litter. The unamended buffer-strip reduced DRP loss by 18%. This increased to 32-40% for all gypsum amended buffer-strips with the rate of gypsum applied having no significant effect. Table 2.7 Performance of buffer strips in reducing total and soluble phosphorus in runoff (adapted from Kay et al., 2009) Pollutant Reduction Reference Total phosphorus 6% reduction McKergow et al. (2003) 10 to 98% reduction Heathwaite et al. (1998) 0 to 97% reduction Uusi-Kämppäetal. (2000) 31% reduction Abu-Zreig. (2001) 8 to 97% reduction Dorioz et al. (2006) 27% decrease to 41% increase Borin et al. (2005) 16% reduction Vaananen et al. (2006) 61% increase McKergow et al. (2003) 17% decrease–475% increase Borin et al. (2005) 0 to 30% decrease Dorioz et al. (2006) Soluble phosphorus Although these systems mainly use waste products (such as WTR, FGD, etc), they would be unfeasible on a large-scale due to availability of the waste products and cost of installing systems on a large-scale. Therefore, these P mitigation technologies are recommended for use in CSA; areas where pollution due to runoff or leaching is likely to occur) only. 2.11.5. Composting Aerobic composting of organic waste is a very effective method of stabilising and sterilising waste materials. Composting manure reduces water content and reduces pathogen survival, kills weed seeds, and is easier to land apply (Eghball and Gilley, 1999). Slurry must be separated before it can be composted and this is the major barrier to their widespread use. Miller et al. (2006) reported that land application of composted cattle manure, rather than fresh cattle manure, may be a potential management tool to 31 control P and N in surface water. Although composting does not sequester P, it converts the manure from a high water content, low nutrient concentration odorous material to a low water content, soil-like material, which is rich in nutrients and can be transported long distances and be used by farmers, or sold to other industries and households as a fertiliser. While composting manure reduces GHG emissions effectively (Pattey et al., 2005), it can cause increases in NH3 emissions (Parkinson et al., 2004). 2.11.6. In-stream and edge of field filters The alternative to reducing P lost to runoff is to recover P from drainage waters. Instream and edge-of-field filters have been examined by many researchers throughout the world (Shipitalo et al., 2010a; McDowell et al., 2008; Bryant et al, 2010; Uusi-Kämppä et al., 2010). Remediation techniques which treat water in-stream include filter socks (Shipitalo et al., 2010a), backfilling tile-drains with P sorbing material (McDowell et al., 2008); various reactive barriers placed along field drains and drainage ways (Bryant et al., 2010; Uusi-Kämppä et al., 2010), reactive materials placed in sub-surface drains (Penn and McGrath, 2011) and ferric sulphate dispensing units (Narvanen et al., 2008). Shipitalo et al. (2010a) found that compost-filled socks (Figure 2.9) were ineffective in reducing P loss from a grassland catchment. In a subsequent study, Shipitalo et al. (2010b) amended the compost with a nutrient sorbent to improve nutrient retention. This resulted in a 27% reduction in DRP in drain water after passing through the filter sock. 32 Figure 2.9 Compost filled socks in instrumented drainage channel (Shipitalo et al., 2010a) Compost socks are not the most effective P sorbing systems. The initial aim of compost filter socks was to prevent SS loss and as the focus has shifted to P loss, researchers have examined more effective P sorbing materials. McDowell et al. (2008) examined the potential for use of industrial by-products to reduce P loss from tiled drained land. In this study, backfilling tile drains with a mixture of 90% melter slag and 10% basic slag 33 reduced DRP and TP from 0.33 mg DRP L-1 and 1.20 mg TP L-1 for control to 0.09 mg DRP L-1 and 0.36 mg TP L-1. Bryant et al. (2010) used a permeable FGD gypsum barrier to intersect ditch water and to precipitate soluble P as calcium phosphate. Between 35 to 90 % of the P from ditch flow that passed through the filter was removed. However, during large flow events, the water flowed over the barrier and this was identified as the main problem associated with such P mitigation systems. Figure 2.10 shows the general layout of such edge of field filters. Figure 2.10 Permeable edge of field barriers (O‘Connor et al., 2010) The ideal situation would be to use materials which can be replenished. Penn and McGrath (2011) examined the ability of steel slag and a surface-modified slag to sorb P in golf course runoff in a flow-through system, and found that both treatments reduced DRP by approximately 31% with the need to replenish slag when it becomes saturated with P. Narvanen et al. (2008) designed a ferric-sulphate doser to treat runoff from a CSA (Figure 2.11). Immediately following chemical treatment, water was passed through a settling pond and then filtered in a sand bed. This system resulted in reductions in DRP and TP in runoff from CSA of 95 and 81%. 34 Figure 2.11 Schematic and photo of ferric-sulphate doser in operation in Jokioinen, Finland (Narvanen et al., 2008) 2.11.7. Sand and woodchip filter systems Researchers have examined the use of sand (Healy et al. 2004) and woodchip filters (Ruane et al., 2011) to treat dairy soiled water. Recently, Carney et al (2011) have examined the effectiveness of wood chip filters in treating the liquid portion of pig slurry following separation (Figure 2.12). There is potential that such systems could be used to treat the liquid portion of dairy cattle slurry following separation. While sand and woodchip filters have been shown to significantly reduce BOD5 and N losses (Healy et al., 2004; Ruane et al., 2011; Carney et al., 2011), they do not reduce P concentrations sufficiently to allow release of wastewaters to waterways. The performance of filters depends on composition of influent and any filter system would require maintenance and constant monitoring to ensure that system was performing properly. While further steps could be included at subsequent stages of treatment to remove P, these systems would require further capital investment. 2.11.8. Slurry separation The objective of slurry separation is to split the slurry into a liquid with low solids content and a solid with high DM. There are three main types of separator: brushed screen separator, decanting separator and screw-press separator. Gilkinson and Frost 35 (2007) carried out a comprehensive study of the brushed screen separator and decanting separator, and found that there was a strong correlation between DM and TP in slurry. Their report conduced that mechanical separation may be an option for farmers with a P and N surplus on farm. Slurry separation requires a significant initial investment and this is likely to be the biggest barrier to implementation. Slurry separation is the first step in treatment as the solid portion of the slurry must be further treated and liquid land applied. Figure 2.12 Pilot scale wood chip filter used to treat the liquid portion of pig slurry following separation (Carney et al., 2011) There has been extensive research into separation of slurry in the US. Currently, approximately 1-2% of dairy farmers in the US use polymers with a flocculent such AlCl3 to help with solids separation (Philip Moore pers com, 2010). Such systems are very effective in reducing TP and soluble P in the liquid portion of separated slurry (Powers et al., 1995; Barrow et al., 1997; Krumpelman et al., 2005). This liquid portion can be land applied on farm to meet N requirements and the solid portion, which is high in P, can be transported off-farm. A summary of reductions of WEP and TP in slurry shown in Table 2.8. 36 Table 2.8 Review of laboratory-scale studies examining chemical aided separation to reduce P in liquid fraction of separated dairy cattle slurry Reference Chemical added TP % Powers et al. (1995) [0.75g CaCO3 + 0.5 ml Fe2(SO4)3] L-1 [0.75g CaO + 0.5 ml Fe2(SO4)3] L Krumpelman et al. (2005) 93 -1 62 -1 74 54 -1 77 67 -1 88 89 -1 92 93 804 mg Fe L + 150 ml 225G-PAM 384 mg Al L + 100 ml 225G-PAM Barrow el al. (1997) 54 -1 [0.5 ml Fe2(SO4)3 + 5 drops polymer] L SS % 278 mg Fe L as FeCl3 358 mg Ca L as CaO 2.11.9. Use of P sorbing amendments Fenton et al. (2008) recommended the addition of amendments to dairy cattle slurry prior to land spreading as a management practice to reduce P losses arising from land application of dairy cattle slurry Ireland. In the U.S.A., chemical amendment of poultry litter has been proven to be effective in reducing P losses from poultry litter and has been used as best management practice for over 30 years (Moore and Edwards, 2005). There has been limited work involving chemical amendment of dairy manure (Dao, 1999; Dou et al., 2003; Kalbasi and Karthikeyan, 2004), however, much more work is needed before chemical amendment can be recommended for implementation as a management practice in Ireland. Phosphorus sorbing amendments can be incorporated into soil to reduce soluble P in soils with high STP (Anderson et al, 1995; Novak and Watts, 2005); or, for incidental losses, added directly to the manure before land application to control P in manure being applied (Moore et al., 1999), or applied after manure application to reduce P losses from applied manure (Torbert et al, 2005). 2.11.9.1. Amendments applied directly to soil Addition of chemical amendments to soils has been shown to reduce P solubility in high P soils and thus the potential to reduce the risk of P loss to waterbodies in surface runoff. Anderson et al. (1995) amended soils with a history of receiving dairy manure in an 37 incubation experiment with calcium carbonate (with the slurry pH adjusted to 7.5), gypsum (0 to 100 g kg-1 soil), ferrous sulphate (0 to 1 g kg-1 as Fe) and alum (0 to 1 g kg-1 as Al). Calcium carbonate effectiveness was limited to soils with pH < 7.0 and gypsum was effective over a broad range of manure loading, pH and redox conditions. Although Al and Fe amendments to soil increased P retention by 400% relative to an unamended control, the authors acknowledged elevated costs associated with amendments and potential biological toxicity. In a laboratory incubation study, Novak and Watts (2005) incorporated an alum-based WTR into three soils with a Mehlich-3 P (M3) of between 145 mg kg-1 and 371 mg kg-1, and found that the amendment reduced WEP in the soil by between 45% and 91% after an 84-d incubation period. They also found that WTR was efficient at reducing M3 of soils with a M3 of between 145 and 235 mg kg-1, but not soil with a M3 of 371 mg kg-1 soil. Stout et al. (1998) amended soil with flyash at 0.01 kg kg-1 soil in a laboratory incubation experiment, and found that M3 and WEP were lowered by 13% and 71%, respectively. Flue gas desulphurisation by-product, applied at 0.01 kg kg-1 soil, lowered M3 by 8% and WEP by 48%. Table 2.9 shows chemical amendments studies with manure type, study type and percentage reductions in WEP of slurry and slurry amended soil. 2.11.9.2. Amendments to slurry The present study examines for the first time the effect of chemical amendment of dairy cattle slurry on P, N and metal (namely Al, Fe and Ca) losses to runoff, whereas most previous studies only examined the effect of amendments on P solubility (Dao, 1999; Dao and Daniel, 2002; Dou et al., 2003). Dou et al. (2003) found that technical grade alum, added at 0.1 kg kg-1 (kg alum per kg slurry) and 0.25 kg kg-1, reduced WEP in swine and dairy slurry by 80% and 99%, respectively. Dao (1999) amended farm yard manure with caliche, alum and flyash in an incubation experiment, and reported WEP reductions in amended manure compared to the control of 21, 60 and 85%, respectively. Kalbasi and Karthikeyan (2004) applied untreated and amended dairy slurry to a soil and incubated it for 2 years; alum and FeCl2 were observed to decrease P solubility, while lime amendments increased WEP. 38 Table 2.9 Results of laboratory and plot-scale chemical amendments studies to date Reference Chemical Rate Manure type Study type % soluble P reduction in: Runoff Dao (1999) Alum Caliche Flyash Dao and Daniel (2002) Cattle stockpiled 0.1 kg kg-1 Cattle composted 0.1 kg kg-1 Cattle stockpiled 0.1 kg kg -1 Cattle composted 0.1 kg kg -1 Cattle stockpiled 0.1 kg kg -1 Cattle composted 21 50 Laboratory 85 93 Dairy slurry Laboratory FeCl3 0.01 kg kg -1 Dairy slurry Laboratory 0.01 kg kg -1 Dairy slurry Laboratory 44 Dairy Laboratory 99 -1 66 0.1 kg kg Flyash 400 g kg-1 Dairy 50-60 -1 Dairy 50-60 Lefcourt and Meisinger (2001) Alum 0.4% (w/w) McFarland el al. (2003) Alum Dairy slurry Laboratory 0.78 kg m-2 Dairy effluent Plot -2 97 Gypsum 0.78 kg m Dairy effluent Plot Meisinger et al. (2001) Alum 6.25% (w/w) Dairy slurry Laboratory Novak and Watts (2005) Al-WTR 1-6% (v/v) None Incubation Smith et al. (2001a) Alum 215 mg Al L-1 Swine Plot Flyash 90 52 45-91 33 430 mg Al L-1 84 215 mg Al L -1 45 430 mg Al L -1 0.01 kg kg-1 84 None Laboratory 71 FGD Zhang et al. (2004) Flyash 82 75 2.5% (w/w) AlCl3 63 18 Alum 400 g kg WEPsoil+waste 60 83 Laboratory 0.01 kg kg-1 FGD Stout et al. (1998) WEPwaste Laboratory Alum Flyash Dou et al. (2003) 0.1 kg kg-1 48 0.4 kg kg -1 -1 Dairy manure Laboratory Laboratory 50-60 Fenton et al. (2009) Ochre 50 g L Dairy effluent Torbert et al (2005) Lime 3:1 metal to P Dairy slurry 99 Gypsum 3:1 metal to P 0 FeSO4 3:1 metal to P 66 0 A limited number of runoff studies have been carried out with chemical amendment of dairy cattle slurry (Elliot et al, 2005; Torbert et al, 2005) and swine slurry (Smith et al, 2001a). Torbert et al. (2005) amended landspread composted dairy manure with lime (3:1 metal-to-TP ratio) immediately prior to a 40-min rainfall event (overland flow equivalent to a rainfall intensity of 12.4 cm h-1). Lime amendments increased DRP loss. In a plot study, Smith et al. (2001a) amended swine manure with alum and AlCl3 at two stoichiometric ratios (0.5:1 and 1:1 Al: TP). Dissolved reactive phosphorus reductions for 39 alum and AlCl3 at the lower ratio were 33% and 45%, respectively, with 84% for both amendments at the higher ratio. Chemical amendments of slurry using Al, Fe, or Ca based compounds reduce P solubility in manure (Dao, 1999; Dou et al., 2003; Kalbasi and Karthikeyan, 2004) and reduce P in runoff from plots receiving alum amended poultry litter (Moore and Edwards, 2005) with negligible effect on metal loss (McFarland et al., 2003). Chemical amendments reduce incidental P losses by a combination of the formation of stable metal-phosphorus precipitates (such as Al-P phosphates in the case of alum) and flocculation of the particles in the slurry to form larger particles, which are less prone to erosion (Tchobanoglous et al., 2003). Previous studies have found that there was no risk of increased metal release posed by chemical amendment of poultry litter (Moore et al., 1998), dirty water (McFarland et al., 2003), or horse manure (Edwards et al., 1999). 2.12. Recommendations and knowledge gaps In Ireland, point source pollution caused by agriculture has been overcome by infrastructural investment on farms and by the removal of point sources in catchments. Attempts to reduce diffuse P loss from agriculture have focused on increasing nutrient efficiency and improving slurry management strategies. In order to meet our water quality obligations, it is becoming apparent that (1) the efficacy of the Nitrates Directive (Ireland‘s agricultural POM) will need time to be assessed and (2) further investigation of mitigation measures (supplementary measures within the WFD), such as those outlined within the EU COST 869 project (coming to a conclusion in October 2011), will be necessary. This review has identified a need for a short-term, cost effective management practice, which can be implemented to reduce the solubility of P in slurry and reduce the risk of incidental and chronic P losses. It is critical that the P mitigation measure selected can mitigate both of these losses. In the long-term, it is likely that a wide range of these technologies will be harnessed in parallel with land application of slurry. 40 In the short-term, however any P mitigation measure must have the ability to be quickly implemented within the existing farm slurry management structure, be cost effective and capable of being used in strategic locations for maximum effect. Chemical amendment of dairy cattle slurry was chosen for further investigation in the present study. Specifically, there have been limited studies involving chemical amendment of dairy cattle slurry and such studies have not considered the feasibility of using amendments at farm-scale, or the changes to the hydrology of a system through their use, pollution swapping and the longterm effects on STP. This is the first study to examine a range of potential chemical amendments for mitigation of P losses from dairy cattle slurry in Ireland. The following knowledge gaps were identified in the present review: 1. There have been no studies conducted to evaluate the effectiveness and feasibility of potential chemical amendments in Ireland. There is a need for such a study if amendments are to be considered for implementation in Ireland. 2. There is a need for a study to examine the effect of chemical amendment of dairy cattle slurry on metal loss to runoff. 3. The effect of chemical amendment of dairy cattle slurry on pollution swapping, in particular N loss to runoff and GHG emissions, needs to be examined 4. The effect of chemical amendment of dairy cattle slurry prior to application to soil on long-term soil WEP and STP. 5. To examine the effect of soil type on the solubility of P in soil following application of amended slurry to soil. 6. To investigate the role chemical amendments may have in mitigation of P losses from dairy cattle slurry in Ireland. 7. To examine conditions in which they work and discuss limitations in use. 41 Chapter 3 3.1. Evaluation of chemical amendments to control phosphorus losses from dairy slurry Overview Land application of dairy slurry can result in incidental losses of P to runoff in addition to increased loss of P from soil as a result of a build up in STP. A novel agitator test was used to identify the most effective amendments to reduce DRP loss from the soil surface after land application of chemically amended dairy cattle slurry. 3.2. Introduction Batch experiments, although allowing quick determination of adsorption capacities of amendments, are unrealistic when considering nutrient losses in runoff following manure application. These small-scale tests do not account for the interaction between applied slurry and soil, and the effect of infiltration and skin formation on the release of P to surface runoff. An ‗agitator test‘, wherein an intact soil core, placed in a beaker, is overlain with continuously-stirred water (Mulqueen et al., 2004), enables achievement of batch experiment results, but also simulates the situation in which slurry is applied to soil, allowed to dry, and then subjected to overland flow (Figure 3.1). The test provides standardised conditions for assessment of the effectiveness of various amendments to slurry at reducing the release of P that may relate to land-applied slurry. The objectives of this study were to: (1) use a laboratory agitator test to identify the most effective chemical amendments to reduce P loss from the soil surface after land application of amended dairy cattle slurry (2) identify optimum amendment application 42 rates for a similar P reduction in different amendments (3) estimate the cost of each treatment, and (4) discuss the feasibility of using treatments in a real on-farm scenario. Figure 3.1 Beakers placed in flocculator during agitator test 3.3. Materials and methods 3.3.1. Soil preparation and analysis Soil samples were collected from a dry stock farm (53°21‘ N, 8°34‘ W) in Galway, Republic of Ireland. 120-mm-high, 100-mm-diameter Al coring rings were used to collect undisturbed soil core samples. Soil samples (n=3) – taken from upper 100 mm from the same location - were air dried at 40 °C for 72 h, crushed to pass a 2 mm sieve and analysed for P using M3 extracting solution (Mehlich, 1984) and Morgan‘s P using Morgan‘s extracting solution (Morgan 43 1941). Soil pH (n=3) was determined using a pH probe and a 2:1 ratio of deionised water-to-soil. Shoemacher-McLean-Pratt (SMP) buffer pH was determined and the lime requirement (LR) of the soil was calculated after Pratt and Blair (1963). The particle size distribution (PSD) was determined using a sieving and pipette method (B.S.1377-2; BSI, 1990a) and the organic content of the soil was determined using the loss of ignition test (B.S.1377-3; BSI, 1990b).The soil used was a poorly-drained, silty loam topsoil, with 15% sand, 72% silt, 13% clay, and an OM content of 16.2±0.2%. The soil texture was classified using the US Department of Agriculture (USDA) soil texture triangle (Figure 3.2). The soil had a M3 concentration of 50±2.8 mg P kg-1 dry soil, Morgan‘s P of 4.6±0.49 mg L-1 (Index 2) and a soil pH of 5.6±0.1. The soil SMP buffer pH was 6.1±0.2 and the LR was 9.9±1 t ha-1. Figure 3.2 United States Department of Agriculture (USDA) soil texture classification triangle used to determine soil texture 44 3.3.2. Slurry sampling and analysis Cattle slurry from dairy replacement heifers was taken from a dairy farm (53°18‘ N, 8°47‘ W) in Galway, Republic of Ireland. The storage tanks were agitated and slurry samples were transported to the laboratory in 10 Litre drums. Slurry samples were stored at 4°C. Slurry pH was determined using a pH probe (WTW, Germany) at 0 h and 24 h; the latter time corresponded with the time the slurry was interacting with the soil in the beaker before being saturated with water. The WEP of slurry was measured at 24 h as suggested by Kleinman et al. (2007). The TP of the dairy cattle slurry was determined after Byrne (1979). Potassium and magnesium (Mg) were analyzed using a Varian Spectra 400 Atomic Absorption instrument, and analyses for N and P were carried out colorimetrically using an automatic flow-through unit. The slurry had a TN concentration of 3982±274 mg L-1, TP of 811±37 mg L-1, total K (TK) of 4009±482 mg L-1, and a pH of 7.3±0.5. 3.3.3. PSM sourcing and analysis The Al-WTR was provided by Galway City water treatment plant (53°17‘ N, 9°03‘ W). Coal combustion by-products were provided by the Electricity Supply Board. The pH of the PSM was measured using 2:1 deionised water: dry amendment ratio. It was possible to measure the pH of the Al-WTR sludge with a pH probe. Dry matter content was determined by drying at 40°C for 72 h. Total metal and P of the PSM was measured by ‗aqua regia‘ digestion using a Gerhard Block digestion system (Cottenie and Kiekens, 1984), which is described by Fenton et al. (2009). The WEP of the PSM was determined after Dayton and Basta (2001). The characteristics of all Al-WTR-1, Al-WTR-2, flyash and FGD are presented in Table 3.1. Al-WTR-1 and Al-WTR-2 had respective Al contents of 11.1% and 5.3% (Table 3.1). Flyash contained 5.6% Al, 4.9% Ca, 2.5% Fe, 12,200 mg kg-1 Mg and 5,460 mg kg-1 TP. FGD contained 20% Ca, 2,950 mg kg-1 Mg and trace amounts of Fe (0.1%) and Al (0.1%). The composition of the commercial grade alum used is also shown. Analytical 45 grade aluminium chloride (13% Al), ferrous chloride (18% Fe) and lime (54% Ca) were used in the experiment. 3.3.4. Agitator test The agitator test comprised 10 different treatments: a grassed sod-only treatment; grassed sod receiving dairy cattle slurry at a rate equivalent to 40 kg TP ha-1 (the study control), and grassed soil receiving 8 different chemically-treated slurries (Table 3.2) applied at a rate equivalent to 40 kg TP ha-1. Amendments were added to slurry in a beaker and mixed for 10 min using a jar test flocculator set at 100 rpm. Each of the 8 amendments were applied at 3 different rates (high, medium and low) in triplicate (n=3). All agitator tests were carried out within 21 d of sample collection. These rates were based results of batch test (Appendix B). Prior to the start of the agitator test, the intact soil samples - at approximately field capacity - were cut to approximately 45 mm depth and transferred from the sampling cores into beakers. This depth of soil in the beakers was considered sufficient to include the full depth of influence on release of P to overland flow (Mulqueen et al., 2004). The chemically-amended slurry was applied to the soil with a spatula (t=0 h), and was then allowed to interact for 24 h prior to saturation of the sample. After 24 h (t=24 h), samples were saturated by gently adding deionised water to the soil sample at intermittent time intervals until water pooled on the soil surface (over 24 h). Immediately after saturation was complete (t=48 h), 500 ml of deionised water was added to the beaker. The agitator paddle was then lowered to mid-depth in the overlying water and rotated at 20 rpm for 24 h, as an attempt to (Figure 3.3). 46 Table 3.1 Characterisation of PSMs and alum used in the agitator test (mean ± standard deviation) tests carried out in triplicate Amendment pH WEP mg kg-1 Al Al-WTR-1 Al-WTR-2 (2 mm) (sludge) 7.9± 0.1 6.9± 0.2 <0.01 Flyash FGD Alum (Al2(SO4)3nH2O) 11.2± 0.04 8.6± 0.0 1.25 <0.01 <0.01 0 4.23 11± 0.0 5.3± 0.2 5.7± 0.2 0.1± 0.0 1.3± 0.1 0.11 4.9± 0.2 20± 0.3 Fe 0.2± 0.0 0.01 2.2± 0.1 0.1± 0.0 K 0.03± 0.0 <0.01 0.1 0.03 As 6.2±1.1 <0.01 13± 0.6 <0.01 1 Cd 0.16± 0.0 <0.01 0.6± 0.0 0.2± 0.02 0.21 Co 0.5± 0.3 <0.01 33± 1 0.3± 0.1 Cr 3.8± 0.21 0.3± 0.02 88± 2 3± 0.1 31.7± 1.5 0.6± 0.03 32.7±1.5 37± 13 165± 33 3.2± 1.7 12,200± 610 2,950± 58 Mn 79± 1 6.9± 0.1 347± 160 31± 0.6 Mo 0.47± 0.2 <0.01 7.7± 0.5 0.73± 0.3 Na 611± 180 65± 14 1370± 610 660± 93 Ni 4.8± 0.06 0.6±0.2 44± 1 11± 0.6 P 234± 5.3 18.7± 1.6 5460± 630 65± 20 Pb 1.2± 0.8 <0.01 30± 2 0.74± 0.4 V 3± 0.2 0.2± 0.01 155± 5 49± 2 Zn 17 0.8± 0.1 75± 31 9.4± 2 Ca Cu Mg % mg kg-1 <0.01 2.1 1.4 2.8 WEP-water extractable phosphorus; Al-WTR-alum-based water treatment residual; FGD-flue gas desulphurisation product. 47 Figure 3.3 Schematic diagram of soil sample in agitator Eight amendments were examined in an agitator test to control diffuse incidental P losses in runoff from slurry applied to permanent grassland. The amendments were divided into commercially available products (chemical amendments) including: industrial grade liquid alum (Al2(SO4)3.nH2O) containing 8% aluminium oxide (Al2O3); laboratory grade aluminum chloride (AlCl3.6H2O); FeCl2 and burnt lime (Ca(OH)2); and P sorbing materials (PSM): aluminium-based water treatment residuals, sieved to less than 2 mm (Al-WTR-1); Al-WTR homogenised sludge (Al-WTR-2); flyash; and FGD.Chemical amendments were applied based on Al:TP stoichiometric rate, and PSM were applied based on a kg kg-1 weight basis (slurry DM). The pH of the amended slurry was measured prior to application at t=0 h. Samples were taken to determine DM and WEP of the amended slurry (Kleinman et al., 2007). Slurry and amended slurry were applied to the surface of the grassed soil at a rate equivalent to 40 kg TP ha-1 (50 m3 ha-1 slurry). For each treatment, slurry samples (n=3) - with the same volume as applied to the grassed sample in the agitator test - were spread at the bottom of another beaker to allow pH and WEP to be measured at 24 h without disturbing the sample used in the agitator test. 48 Table 3.2 Table showing amendments in order of effectiveness score, breakdown of costsa, cost/m3 slurryb, cost for 100 cow farm, percentage reduction in DRP in overlying water and WEP of slurry at 24 h Chemicalc Effectiveness score Costd Rate € tonne-1 kg m-3 250 12 5:1 Fe: P 10:1 Fe: P Addition rate Spreading Agitation Total € m-3 Cost watere € m-3 € m-3 100 cow farm € farm-1 € m-3 0.00 2.92 1.58 0.33 0.00 1.91 1010 1.57 0.34 0.00 4.82 2550 88 29 1.7± 0.27 36 7.29 1.60 0.34 0.00 9.23 4870 90 0.2± 0.06 72 58 14.59 1.64 0.35 0.00 16.58 8750 99 0.5± 0.02 81 17 4.76 1.58 0.34 0.00 6.67 3520 87 2.06± 0.06 21 19 5.23 1.58 0.34 0.00 7.15 3770 92 1.43± 0.02 46 37 10.45 1.61 0.35 0.00 12.41 6550 99 0.16± 0.02 94 19 2.82 1.60 0.34 0.00 4.76 2520 83 0.51± 0.01 81 1.22:1 Al: P 24 3.53 1.59 0.34 0.00 5.46 2880 94 0.27± 0.07 90 2.44:1 Al: P 47 7.07 1.62 0.35 0.00 9.04 4770 99 0.03± 0.0 99 150 2.03 3.23 0.69 2.14 8.09 4270 72 0.09± 0.0 97 300 4.05 4.90 1.05 4.28 14.28 7540 89 0.05± 0.0 98 400 5.40 5.84 1.26 5.45 17.95 9480 91 0.04± 0.0 99 150 2.03 2.50 0.54 1.07 6.13 3240 43 0.92± 0.14 65 4.2 kg kg-1 300 4.05 3.62 0.78 2.37 10.82 5710 72 0.24± 0.08 91 5.6 kg kg-1 400 5.40 4.25 0.92 3.09 13.66 7210 81 0.22± 0.04 92 Control FeCl2 1 (FeCl3) AlCl3 2 (PAC) 2:1 Fe: P 0.98:1 Al: P 280 1.22:1 Al: P 2.44:1 Al: P Alum FGD 3 4 0.98:1 Al: P 1.33 kg kg-1 2.65 kg kg 150 14 -1 3.5 kg kg-1 Flyash Ca(OH)2 Al-WTR-1 5 6 7 (<2 mm) Al-WTR-2 (sludge) 8 2.1 kg kg-1 1:1 Ca: P 14 312 Cost amendment DRP WEP (t=24h) WEP %P mg kg-1 % 2.64± 0.15 2 0.48 1.55 0.33 0.00 2.37 1250 0 2.43± 0.06 9 5:1 Ca: P 8 2.40 1.56 0.34 0.00 4.30 2270 74 1.52± 0.02 42 85 10:1 Ca: P 15 4.81 1.57 0.34 0.00 6.72 3550 81 0.4± 0.0 0.28 kg kg-1 20 - - - - - - 31 2.49± 0.06 6 0.69 kg kg-1 50 - - - - - - 77 1.73± 0.02 34 1.4 kg kg-1 100 - - - - - - 74 0.93± 0.02 65 0.28 kg kg -1 63 0.31 1.65 0.35 0.00 2.31 1220 0 1.13± 0.05 57 0.69 kg kg-1 5 156 0.78 1.88 0.40 0.13 3.20 1690 71 0.28± 0.01 89 1.4 kg kg-1 313 1.56 2.52 0.54 0.72 5.34 2820 67 0.07± 0.0 97 DRP-dissolved reactive P; WEP-water extractable P; Al-WTR-alum-based water treatment residual; FGD-flue gas desulphurisation product; aCalculations based on a dairy farm with 100 cows, or equivalent stocking rate, with a 18-wk winter; bSlurry properties: TP = 811 mg L-1 and 7.2% DM; cWhere analytical grade products were used, cost was estimated using the most similar commercial product on the market (in brackets); dCost includes delivery of material and addition of material to slurry in storage tank; eAddition of some amendments resulted in DM >10%water addition needed for spreading. 49 3.3.5. Water sampling and analysis Water samples (4 ml) were taken from mid-depth of the water overlying the soil at 0.25, 0.5, 1, 2, 4, 8, 12 and 24 h after the start of each test (i.e after the 500 ml was added). All samples were filtered immediately after sample collection using 0.45 μm filters and placed in a freezer (APHA, 1995) prior to being analysed colorimetrically for DRP using a nutrient analyser (Konelab 20, Thermo Clinical Labsystems, Finland). The DRP concentrations were used to calculate the mass of DRP in the water overlying the soil samples in the beaker, taking into account the water volume reduction as the test progressed. All water samples were tested in accordance with standard methods (APHA, 1995). Figure 3.4 shows the P classification system used in this study (adapted from APHA). 3.3.6. Statistical Analysis Proc Mixed (SAS, 2004) was used to model the factorial structures (amendment*application rate; and amendment*application rate*time) in the experiment in order to allow for heterogeneous variance across treatments. A group variable was fitted to allow comparisons between the control treatments and the factorial combinations. A multiple comparisons procedure (Tukey) was used to compare means. 3.3.7. Cost analysis The cost of chemical amendment was calculated based on the estimated cost of chemical, chemical delivered to farm, addition of chemical to slurry, increases in slurry agitation, and slurry spreading costs as a result of increased volume of slurry due to the addition of the amendments. Slurry spreading costs were estimated based on data from Lalor (2008) and slurry agitating costs were estimated based on data from Anon (2008). The cost of water required to maintain DM at less than 10% was included, as DM must be less than 10% for ease of handling (Stan Lalor pers com, 2010). The feasibility of amendments 50 was determined based on effectiveness, rate, potential barriers to use and cost of implementation. Runoff water sample ↓ DRP (Dissolved reactive P) TDP (Total dissolved P) ← ↓ → Filtered (0.45 μm filter) Unfiltered ↓ ↓ Persulphate digestion Persulphate digestion ← DUP (Dissolved unreactive P) = TDP-DRP → TRP (Total reactive P) TP (Total P) PP (Particulate P) = TP-TDP Figure 3.4 Phosphorus classification system used in this study (APHA, 1995) 3.4. Results 3.4.1. Results of agitator test The amendments that were most effective at reducing DRP in overlying water were: FeCl2 (99%), AlCl3 (99%), alum (99%), FGD (91%), flyash (81%), lime (81%), AlWTR-1 (71%) and Al-WTR-2 (77%). Figure 3.5 shows the mass of DRP in overlying for each treatment at each rate is shown in Figure 3.6. The amendments are ranked in decreasing order of effectiveness in Table 3.3. The irregularity between the 0.69 and 1.4 kg kg-1 amendment rates for Al-WTR-1 and Al-WTR-2 treatments were consistent across sieved and sludge treatments. However, this was not statistically significant. The overall statistical analysis showed that there was a significant interaction between treatment and application rate, but that the interaction effects were small compared to the main effects. Optimum application rates were determined based on achieving a similar level of P reduction for each of the amendments, while applying the minimum amount of metals to land, thus reducing risk due to land spreading of metals. Based on this criterion, optimum amendment rates were: FeCl2 (2:1 (Fe:P)), AlCl3 and alum (0.98:1 (Al:P)), FGD (1.33 kg kg-1), flyash (4.2 kg kg-1), lime (5:1 (Ca:P)), Al-WTR-1 and Al-WTR-2 (0.69 kg kg-1). 51 Slurry-control Grass 800 12 10 8 6 4 2 0 600 400 200 0 Aluminium chloride 12 10 8 6 4 2 0 600 200 0 FeCl2 Lime 800 12 10 8 6 4 2 0 600 400 200 0 Al-WTR-1 Al-WTR-2 800 12 10 8 6 4 2 0 600 400 200 0 FGD Flyash 800 12 10 8 6 4 2 0 600 400 200 0 0 4 8 12 16 20 0 4 8 12 Time from start of agitator test (hours) 16 Figure 3.5 Mass of DRP and DRP concentration in overlying water 52 20 C Mass P released in overlying water at time t (mg m-2) 400 Concentration of dissolved reactive P in overlying water (mg L-1) Aluminium sulphate (alum) 800 Linear regression showed a strong relationship between percentage reduction in slurry WEP and DRP in water overlying the soil for alum (R2=0.95), AlCl3 (R2=0.99), AlWTR-2 (R2=0.94), flyash (R2=0.96), FGD (R2=0.83); and a smaller relationship for FeCl2 (R2=0.60), lime (R2=0.75) and Al-WTR-1 (R2=0.67). Only three rates were examined and there were insufficient points to quantify any relationship. 100 80 10 60 AlCl2 (PAC) FeCl2 40 Ca(OH)2 5 Al-WTR-2 FGD 20 Flyash Al2(SO4) 0 0 0 5 10 15 Percentage reduction in DRP release to overlying water (%) Reduction in DRP released from soil ( kgha-1) 15 20 Total cost of chemical amendment of slurry (euro t-1) Figure 3.6 Total cost of chemical amendment of dairy cattle slurry plotted against the reduction in dissolved reactive phosphorus (DRP) lost to overlying water and the percentage reduction in DRP release to overlying water 3.4.2. Cost and feasibility analysis The estimated cost of addition of amendments and increases in spreading and agitation costs due to amendments are presented in Table 3.2. The effects of amendments on slurry viscosity or handling were not considered in the cost analysis. It was assumed that 53 amendments would be added upon delivery, so storage cost on site was excluded from the analysis. For analytical grade products, the cost was estimated using the most similar commercial product available on the market. Starting with the cheapest, the amendments were ranked as follows: Al-WTR-2 (€3.20 m-3); Ca(OH)2 (€4.30 m-3); alum (€4.76 m-3); FeCl3 (€4.82 m-3); poly aluminium chloride (€6.67 m-3); FGD (€8.10 m-3) and flyash (€10.80 m-3). Table 3.3 Feasibility of amendments Chemical Feasibility score Addition rate Total cost € m-3 Reduction in DRP %P Notes Alum 1 0.98:1 Al: P 4.76 83 Risk of effervescence Risk of release of H2S due to anaerobic conditions and reduced pH Cheap and used widely in water treatment AlCl3(PAC) 2 0.98:1 Al: P 6.67 87 No risk of effervescence (Smith et al, 2004) AlCl3 increased handling difficulty Expensive FeCl2(FeCl3) 3 2:1 Fe: P 4.82 88 Potential for Fe bonds to break down in anaerobic conditions Potential increased release of N2O Ca(OH)2 4 5:1 Ca: P 4.30 74 Risk of increased NH3 loss Strong odour Hazardous substance Al-WTR-2 (sludge) 5 0.69 kg/kg 3.20 71 Waste product Risk of release of H2S Composition varies with location and time Risk of P deficiency if over applied High application rates required Limited supply FGD 6 1.33 kg/kg 8.10 72 High pH and therefore risk of increased NH3 loss Strong odour Large application rates required Settles quickly Potentially toxic Flyash 7 4.2 kg/kg 10.80 72 Al-WTR-1 (<2 mm) 8 0.69 kg/kg - 77 Contains heavy metals Huge volume of water required Settles quickly Potentially toxic Excluded from cost analysis The effect of amendments on slurry pH is a potential barrier to their implementation, as it affects P sorbing ability (Penn et al., 2011) and NH3 emissions from slurry (Lefcourt and 54 Meisinger, 2001). Slurry pH results are shown in Figure 3.7.The acidifying additives (alum, AlCl3, FeCl2) lowered the pH of the slurry. Lime and flyash addition increased the pH to 10.3 (p<0.0001) and 9.3 (p<0.0001), respectively. The use of these high pH amendments is likely to result in an increase in NH3 emissions to the atmosphere from slurry. Risk of increased metal concentrations in overland flow is a significant barrier to the use of these amendments. No analysis of metals in the overlying water was undertaken in this experiment; therefore, feasibility considerations for metal application rates were based on the principal of applying the minimum metals necessary to reduce DRP in the overlying water. In addition, flyash was deemed unsuitable due to high concentrations of heavy metals contained within it. 12 Slurry/amended slurry pH 10 8 6 4 2 Ca(OH)2 Al-WTR-1 Al-WTR-2 -1 Flyash 1..33 kg kg -1 2.65 kg/kg -1 3.5 kg kg -1 2.1 kg kg -1 4.2 kg kg -1 5.6 kg kg FeCl2 -1 2:1 Fe:P 5:1 Fe:P 10: 1 Fe:P PAC 0.28 kg kg -1 0.69 kg kg -1 1.4 kg kg 0.98:1 Al:P 1.22:1 Al:P 2.44: Al:P Alum 0..28 kg kg -1 0.69 kg kg -1 1.4 kg kg 0.98:1 Al:P 1.22:1 Al:P 2.44: Al:P Slurry 1:1 Ca:P 5:1 Ca:P 10: 1 Ca:P Control Rate -1 0 FGD Figure 3.7 Histogram of slurry pH at time of amendment/application (clear box) and pH of slurry after 24 h (hatched box) 55 3.5. Discussion Chemical amendment is an attractive means of mitigating against both incidental P losses from slurry and elevated P release from soil resulting from the increase in soil P due to slurry and chemical fertiliser application. It could be used in strategic areas for protection of a waterbody while allowing farmers to utilise other nutrients in slurry on farms with high STP. Ferric chloride, AlCl3 and alum were the most effective amendments at optimum rates. Aluminium water treatment residuals, flyash and FGD are not feasible due to the large application rates needed and the risk of over-application of metals. Although chemical amendments are expensive, they are widely available and more efficient than PSM, and lower metal application rates are required to achieve adequate P reductions at optimum application rates. The results for FeCl2, AlCl3, alum, and lime were in agreement with other studies. Lefcourt and Meisinger (2001) reported a 97% reduction in DRP of dairy cattle slurry when 2.5% by weight of alum was added in a laboratory batch experiment. The Al-WTR used in the present study was less effective than those observed in other studies. Penn et al. (2011) reported an 80% reduction in WEP of dairy slurry when slurry was amended at a rate equivalent to 0.2 kg kg-1 (compared to 71% observed in this study at 0.69 kg kg-1). The results for the coal combustion by-products differed to previous studies. Dou et al. (2003) found that adding flyash to dairy manure at 0.4 kg kg-1 (manure DM) lowered soluble P by between 50 and 60% compared to 43% at 2.1 kg kg-1 in the present study. Penn et al. (2011) found that FGD was ineffective in treating dairy slurry when applied at 0.2 kg kg-1, which was in contrast to the results of the present study (72% at 1.33 kg kg-1). This difference could be due to the difference in composition of flyash. The mass of P released and DRP of the overlying water at any time for the duration of the experiment are shown in Figure 3.5. Throughout this study, an initial high rate of DRP release was followed by a period of slower release and, after 12 h, an approximate equilibrium DRP concentration was reached with the exception of the highest application rate of Al-WTR and all FGD treatments. 56 The stability, and thus the effectiveness, of different amendments over longer time spans (months, years) depends on farm management systems, drainage, and soils to which they are applied. For example, Al-P bonds are most stable in acidic soils, while Ca-P bonds are more stable in calcareous conditions (Wild, 1988). The effect of treatment on slurry pH at the time of application affects P sorption capacity of PSM containing Ca compounds, and NH3 emissions from slurry. Changes in pH may reduce the pathogen load in slurry and subsequently pathogen transport to soil and runoff. Application of AlWTR and FGD did not significantly change slurry pH. The soil used had optimum STP and only required P inputs sufficient to maintain P levels for future agronomic needs. Slurry amendment type (treatment), rate of amendment addition (rate), and their interaction had an effect on DRP in runoff (p< 0.0001; R2=0.96). This strong relationship between slurry WEP and overlying water DRP would suggest that for this particular soil with this STP, soil type and STP had a minimum impact on results; in addition, any effect of STP would be constant across all treatments. Sharpley and Tunney (2000) reported that STP had little impact on the release of P to runoff for up to 14 d after dairy cattle slurry application. There have been many reports of human and animal deaths from the release of the toxic hydrogen sulphide gas when slurry is being agitated on farms. The addition of chemicals such as alum that can lead to acidification of slurry and are likely to increase the release of toxic hydrogen sulphide gas and great care should be taken when adding acidifying chemicals to slurry on the farm. Public and stakeholder opinion is the main obstacle for the use of chemical amendments. This study examined the feasibility of the amendments based on effectiveness, optimum rates and cost of treatment. Future work must address public concerns and examine the impact of amendments on gaseous emissions and metal build-up in the soil. If amendments to slurry are to be recommended (and adopted) as a method to prevent P losses in runoff, the impact of such applications on slurry-borne pathogens, as well as pathogen translocation to the soil and release in surface runoff, needs to be addressed. The long-term effects on microbial communities in soil must also be examined. 57 There is no provision for a licence to landspread any of these amendments in Ireland (lime is land applied in acidic soils to optimise soil pH for production) and if chemical amendment were to be used to mitigate P losses, a licensing system would have to be introduced by the Department of Agriculture in Ireland and relevant bodies in other countries. 3.6. Conclusions The findings of this chemical amendment study are: 1. All amendments, when added to slurry, greatly reduced WEP of the slurry and DRP in water overlying soil. 2. Even at optimum amendment rates, the cost of slurry treatment increases slurry handling cost (between 250 and 560%) with the exception of Al-WTR, which is unfeasible due to high rates required, concerns over variation in composition, and limited supply. 3. These treatments currently seem to be expensive. However, they may be feasible if used strategically to mitigate P loss from dairy slurry in CSA within a farm, or as an alternative to applying slurry to high P soils. 4. Chemical amendments may have a role to play as part as P mitigation strategy 3.7. Summary This chapter has determined the most effective amendments at reducing DRP release from land applied slurry to runoff. Chapter 4 details a runoff-box experiment designed to develop an understanding of the performance of chemical amendments under more realistic conditions. In addition to examining DRP, Chapter 4 examines how amendments affect SS, PP and TP losses. Chapter 4 also examines the effect of amendments on incidental loss of metals (Al, Ca and Fe) to runoff. 58 Chapter 4 4.1. Laboratory-scale rainfall simulation experiment Overview The agitator test identified amendments with great potential to reduce P solubility. A runoff box experiment was designed to develop our understanding of the performance of amendments under more realistic conditions. 4.2. Introduction Chemical amendments of slurry using Al, Fe, or Ca based compounds reduce P solubility in manure (Dao, 1999; Dou et al., 2003; Kalbasi and Karthikeyan, 2004) and reduce P in runoff from plots receiving alum amended poultry litter (Moore and Edwards, 2005) with negligible effect on metal loss (McFarland et al., 2003). Chemical amendments reduce incidental P losses by a combination of the formation of stable metal-phosphorus precipitates (such as Al-P phosphates in the case of alum) and flocculation of the particles in the slurry to form larger particles, which are less prone to erosion (Tchobanoglous et al., 2003). Previous studies have found that there was no risk of increased metal release posed by chemical amendment of poultry litter (Moore et al., 1998), dirty water (McFarland et al., 2003), or horse manure (Edwards et al., 1999).The present study examines for the first time the effect of chemical amendment of dairy cattle slurry on both P and metal (namely Al, Fe and Ca) losses to runoff, whereas most previous studies only examined the effect of amendments on P solubility (Dao, 1999; Dao and Daniel, 2002; Dou et al., 2003). 59 4.3. Materials and Methods 4.3.1. Soil sample collection and analysis Intact grassed-soil samples, 70 cm-long by 30 cm-wide by 10 cm deep, were collected from a dairy farm in Athenry, Co. Galway (53°21‘N, 8°34‘ W). A second set of soil samples, taken to a depth of 10 cm below the ground surface from the same location, was air dried at 40 °C for 72 h, crushed to pass a 2 mm sieve, and analysed for Morgan‘s P (the national test used for the determination of plant available P in Ireland) using Morgan‘s extracting solution (Morgan, 1941). Soil pH (n=3) was determined using a pH probe and a 2:1 ratio of deionised water-to-soil. Particle size distribution was determined using B.S.1377-2:1990 (BSI, 1990a). Organic content of the soil was determined using the loss of ignition test (B.S.1377-3; BSI, 1990b). The soil was a poorly-drained sandy loam (58% sand, 27% silt, 15% clay) with a Morgan‘s P of 22±3.9 mg P L-1, a pH of 7.45±0.15 and an OM content of 13±0.1%. The soil had a sandy loam texture, which points to moderate drainage on site. However, medium permeable subsoil limits drainage. Historic applications of organic P from an adjacent commercial-sized piggery have led to high STP in the soil used in this study. 4.3.2. Slurry collection and analysis Cattle slurry from dairy replacement heifers was taken from a farm (53°18‘ N, 8°47‘ W) in County Galway, Republic of Ireland in Winter (February), 2010. The storage tanks were agitated and slurry samples were transported to the laboratory in 10-L drums. Slurry samples were stored at 4°C. Slurry and amended slurry pH was determined using a pH probe (WTW, Germany) and the WEP of slurry was measured at the time of land application after Kleinman et al. (2007). Dry matter content was determined by drying at 105 °C for 16 h. The TP of the dairy cattle slurry was determined after Byrne (1979). Total potassium, TN and TP were carried out colorimetrically using an automatic flowthrough unit (Varian Spectra 400 Atomic Absorption instrument). Ammoniacal nitrogen of slurry and amended slurry was extracted from fresh slurry by shaking 10 g of slurry in 60 200 ml 0.1 M HCl on a peripheral shaker for 1 h and filtering through No 2 Whatman filter paper. 4.3.3. Slurry amendment and runoff set-up The results of a laboratory micro-scale study (Chapter 3) (Data shown in Appendix C) were used to select chemical amendments to be examined in the present study. In addition to a grassed soil-only treatment, five treatments were examined: (1) slurry-only (the study control) (2) industrial grade liquid alum (Al2(SO4)3.nH2O), comprising 8% aluminium oxide (Al2O3) applied at a rate of 1.11:1 (Al:TP) (3) industrial grade liquid polyaluminium chloride hydroxide (PAC) (Aln(OH)mCl3n-m) comprising 10% Al2O3 at a rate of 0.93:1 (Al:TP) (4) analytical grade FeCl2 at a rate of 2:1 (Fe:TP), and (5) burnt lime (Ca(OH)2) at a rate of 10:1 (Ca:TP). The rates used were based on the results of Chapter 3. A batch experiment was also conducted using a range of amendment concentrations to construct a multi-point Langmuir isotherm (McBride, 2000): P x/m = 1 + P ab b (4.1) where P is the concentration of P in solution at equilibrium (mg L-1), x/m is the mass of P adsorbed per unit mass of amendments (g kg-1) at P, a is a constant related to the binding strength of molecules onto the amendments, and b is the theoretical amount of P adsorbed to form a complete monolayer on the surface. This provided an estimate of the maximum adsorption capacity of the amendments (g kg-1). These results are shown in Figure 4.1. The amendments were added at a range of rates to 500 g slurry samples and mixed rapidly for 10 min at 100 rpm using a jar test flocculator. The samples were incubated at 11°C for 24 h. Following incubation, 50 g of slurry/amended slurry was mixed with 250 ml of distilled water. The slurry-water solution was then placed on a reciprocating shaker for 1 h. Samples were centrifuged at 14,000 rpm for 5 min to separate the solids from the 61 solution before being passed through a 0.45 µm filter and the P extract was determined using a Konelab nutrient analyser (Konelab 20, Thermo Clinical Labsystems, Finland). 1 0.6 0.8 0.6 0.4 0.4 Alum, a = 1 b = 1 g P kg-1 alum 0.2 0.2 PAC, a = 1 b = 0.52 g P kg-1 PAC P/(x/m) (mg L-1) 0 0 1 2 3 4 0 5 0 6 6 5 4 3 2 1 0 5 4 3 2 FeCl2, a = 0.7 b = 11.2 g P kg-1 FeCl2 1 0 0 1 2 3 4 1 5 2 3 4 5 Ca(OH)2, a = 0.35, b = 9.2 g P kg-1 Ca(OH)2 0 1 2 3 4 5 P (mg L-1) Measured data Modelled data Figure 4.1 Langmuir isotherm fitted to phosphorus in amended slurry data The equilibrium P concentration (EPC0) (i.e. the point where no net desorption or sorption occurs) was derived using the following formula (Olsen and Watanabe, 1957): S‘ = kdP-S0 (4.2) where S‘ is the mass of P adsorbed from slurry (mg kg-1), P is the final P concentration of the solution, kd is the slope of the relationship between S‘ and P, and S0 is the amount of P originally sorbed to the amendment (mg L-1). The EPC0 was determined graphically (Figure 4.2). 62 A slurry sample (from the same storage tank as used in the surface runoff experiments) with a DM of 6%, TP of 550 mg L-1 and WEP of 2.26 g kg-1 was used for the isotherm study. An approximate metal: soluble P ratio for each amendment was calculated using the b term from the Langmuir isotherm and WEP of the slurry. The isotherm results indicated that lower application rates should be sufficient to bind P in slurry. However, as the experiment detailed in Chapter 3 was considered to best replicate runoff, it was decided to base the application rates on the results of Chapter 3 and not the batch test used to develop the Langmuir isotherm. As one of the main aims of the present study was to investigate the effect of amendments on metal release, it was considered to be reasonable and conservative to use results from Chapter 3. 1200 1000 800 800 600 600 400 400 200 Alum, EPC0 = ~0 200 0 0 S‘ (mg kg-1) PAC, EPC0 = ~0 0 10 0 20 10 20 12000 10000 8000 8000 6000 6000 4000 4000 FeCl2 2000 2000 Ca(OH)2 0 0 0 2 4 0 6 5 10 15 20 -1 P (mg L ) Figure 4.2 Phosphorus sorption isotherms for amended slurry data A laboratory runoff box study was chosen over a field study as it was less expensive and allowed testing under standardized conditions. Such studies are a widely used tool in P transport research to compare treatments (Hart et al., 2004). This experiment used two 63 laboratory runoff boxes, 200-cm-long by 22.5-cm-wide by 5-cm-deep with side walls 2.5 cm higher than the soil surface, and 0.5-cm-diameter drainage holes located at 30-cmcentres in the base (after Regan et al., 2010). Cheese cloth was placed at the base of each runoff box before placing the sods to prevent soil loss. Intact grassed sods from the study site were transported to the laboratory and stored at 11°C in a cold room prior to testing. All experiments were carried out within 14 d of sample collection and tests were conducted in triplicate (n=3). Immediately prior to the start of each runoff box experiment, new sods were trimmed and placed in the runoff box; each slab was butted against its adjacent slab to form a continuous surface. Molten candle wax was used to seal any gaps between the soil and the sides of the runoff box, while the joint between adjacent soil samples did not require molten wax. The packed sods were then saturated using a rotating disc, variable-intensity rainfall simulator (after Williams et al., 1998), comprising a single 1/4HH-SS14SQW nozzle (Spraying Systems Co., Wheaton, IL) attached to a 450-cm-high metal frame, and calibrated to achieve an intensity of 11.5±1 mm h-1 and a droplet impact energy of 26 kJ cm-1 ha-1 at 85% uniformity. The sods were then left to drain for 24 h before the experiment commenced; the grassed sods were then assumed to be at an approximate ‗field capacity‘ (Regan et al., 2010). Amendments were added to the slurry and mixed rapidly (10 min at 100 rpm) using a jar test flocculator immediately prior to land application. Slurry and amended slurry were applied directly to the surface of the intact grassed soil in runoff boxes at a rate equivalent to 33 m3 slurry ha-1 (26 kg TP ha-1), the rate most commonly used in Ireland (Coulter and Lalor, 2008). Figure 4.3 shows soil sods before and after slurry application. During each rainfall simulation event, rain was applied until runoff water flowed continuously and then for 1 h while runoff water samples were collected. The drainage holes on the base of the runoff boxes were sealed to better replicate field conditions and to ensure that overland flow occurred. Figure 4.4 shows the laboratory setup. 64 a b Figure 4.3 Runoff box immediately (a) before and (b) after slurry application 65 Runoff box cleaned prior to each Muslin cloth cut to length to Runoff box ready for soil to be rainfall simulation prevent soil loss and aid drainage placed Soil sample trimmed Soil samples placed in flume View of runoff box with one sod immediately prior to placement starting at lower end Figure 4.4 Photographs showing soil sod preparation and placement methodology The first rainfall simulation (RS1) commenced 48 h after slurry application, then after a 1 h interval the second rainfall simulation (RS2) commenced. The drainage holes at the bottom of the runoff box were opened for a 24 h interval and then closed when the third rainfall event (RS3) commenced. As the soil samples were taken from the mid-slope of a field with a slope of approximately 5%, it would have been unrealistic to allow the soil to remain water-logged for 24 h between RS2 and RS3. All of the surface runoff was collected at 5-min intervals once runoff began. The source for the water used in the rainfall simulations had a DRP concentration of less than 0.005 mg L-1, a pH of 7.7±0.2 66 and an electrical conductivity (EC) of 0.435 dS m-1. Runoff water pH and EC were measured immediately prior to each event using a pH and EC meter. 4.3.4. Sample handling and analysis Runoff samples were collected in 1 L containers (covered to prevent rain water entering container) at the bottom of the runoff box. Immediately after collection, a subsample of the runoff water was passed through a 0.45µm filter and a sub-sample was analysed colorimetrically for DRP using a nutrient analyser (Konelab 20, Thermo Clinical Labsystems, Finland). A second filtered sub-sample was analysed for TDP using potassium persulfate and sulfuric acid digestion (HACH LANGE, Germany). Unfiltered runoff water samples were also collected and TP was measured using the method used for TDP analysis. Particulate P was calculated by subtracting TDP from TP. The DRP was subtracted from the TDP to give the DUP. Suspended sediment were determined for all samples by vacuum filtration of well-mixed, unfiltered runoff water through Whatman GF/C (pore size: 1.2 µm) filter paper. All water samples were tested in accordance with standard methods for the examination of water and wastewater (APHA, 1995). In order to address the concern of metal release from amendments, identified by Fenton et al. (2008), it was decided to measure Al, Ca and Fe as these were the active metals in the chemical amendments added to slurry. The metal content was determined using an ICP (inductively coupled plasma) VISTA-MPX (Varian, California). The limit of detection for Al and Fe was 0.01 mg L-1 and 1 mg L-1 for Ca. 4.3.5. Statistical analysis The structure of the experiment was a one-way classification with the rainfall events being repeated measures on each experimental unit. Proc Mixed of SAS (2004) was used to analyse the concentrations of DRP, DUP, PP, TP, SS, Al, Ca and Fe with a covariance structure to account for correlations between the repeated measures. An unstructured 67 covariance model was used for most variables and the outcome was interpreted as a factorial of treatment x event. In all cases, the treatment by event interactions were examined. The data for Al and Fe were censored by a limit of detection and PROC NLMIXED of SAS was used to fit a censored Normal-based model while accounting for the correlations by inducing a compound symmetry structure with a random effect. 4.4. Results 4.4.1. Slurry and amended slurry analysis The results of the slurry analysis are shown in Table 4.1. The slurry sample was typical of slurry found on farms in Ireland (SI 610 of 2010) with a high DM on the upper limit for land application (Stan Lalor pers com, 2011). The slurry TP and TK remained relatively constant. At the rates used in this study, all of the amendments examined reduced the WEP of dairy cattle slurry by approximately 99% compared to the slurry-control (p<0.001). Alum addition reduced slurry pH from approximately 7.5 (control) to 5.4, PAC reduced pH to 6.4 and FeCl2 to 6.7 (p<0.001), while lime addition increased slurry pH to 12.2 (p<0.001). Chemical amendment also changed the appearance of slurry (Figure 4.5) Table 4.1 Stoichiometric ratio at which the amendments were applied and slurry dry matter (DM), pH and average concentrations of NH4- N, water extractable phosphorus (WEP), total nitrogen (TN), total phosphorus (TP) and total potassium (TK) (n=3) Rate DM pH % Slurry NH4-N WEP TN TP TK mg L-1 g kg-1 DM mg L-1 mg L-1 mg L-1 10.5 (0.04) 7.47 (0.1) 1760 (123) 2.22 (0.34) 4430 (271) 1140 (76) 4480 (218) Alum 1.1:1 [Al:TP] 9.4 (0.16) 5.40 (0.1) 1770 (21) 0.002 (0.0004) 4570 (176) 1140 (69) 4360 (84) PAC 0.93 [Al:TP] 9.6 (0.28) 6.37 (0.1) 1760 (143) 0.0013 (0.0003) 4750 (448) 1180 (165) 4680 (448) Lime 10:1 [Ca:TP] 8.2 (0.29) 12.2 (0.1) 1320 (141) 0.0056 (0.0003) 3190 (263) 1140 (96) 4810 (227) FeCl2 2:1 [Fe:TP] 10.1 (0.22) 6.7 (0.1) 1700 (11) 0.0022 (0.0006) 4340 (372) 1120 (51) 4720 (386) (standard deviation in brackets) 68 Lime FeCl2 Alum PAC Slurry-control Figure 4.5 Photographs of slurry and amended slurry immediately after application to grassed soil in boxes 4.4.2. Water quality analysis The average flow-weighted mean concentrations (FWMC) of DRP, DUP and PP in runoff for the three rainfall events are shown in Figure 4.6. Alum (114 μg DRP L-1) and PAC (89 μg DRP L-1) were more effective at reducing DRP concentration than lime (200 μg DRP L-1) and FeCl2 (200 μg DRP L-1). At the rates used, all of the treatments 69 examined resulted in DRP concentrations in runoff greater than the MAC for surface waters. However, the buffering capacity of water means that the concentration of a surface waterbody will not be as high as the concentration of runoff, provided runoff from slurry flows over soil which has not received dairy cattle slurry (McDowell and Sharpley, 2002b). The average concentrations of P in runoff water for the 3 rainfall simulation events were 171 µg DRP L-1, 91 µg DUP L-1 and 373 µg TP L-1 for grassed soil-only treatment compared to 655 μg DRP L-1, 1,290 μg DUP L-1 and 8,390 μg TP L-1 for the slurrycontrol. Incidental DRP and TP concentrations in runoff water following land application of dairy cattle slurry were 5 and 14 times greater than those from grassed-soil. In the present study, alum (p<0.001), PAC (p<0.001), lime (p<0.05) and FeCl2 (p<0.05) reduced DRP losses significantly compared to the slurry-control with reductions similar to those observed in Chapter 3. The results of both studies are tabulated in Table 4.2. The average FWMC of TDP was significantly reduced compared to the slurry-control. The difference between grass-only, alum and PAC treatments was not significant and the difference between lime and FeCl2 was also not significant. The average FWMC of DUP was also significantly reduced for all treatments compared to slurry-control. 70 14 PP Phosphorus (mg L-1) 12 DUP DRP 2 1 10 8 6 4 2 0 1 2 3 1 Slurry 2 3 1 Alum 2 3 1 PAC 2 3 1 Lime 3 FeCl2 2 3 Grass Phosphorus (mg L-1) (Log scale) 100 PP DUP DRP 2 1 10 1 0.1 0.01 1 2 Slurry 3 1 2 Alum 3 1 2 3 PAC 1 2 Lime 3 1 FeCl2 3 2 3 Grass Figure 4.6 The average flow-weighted mean concentration of dissolved reactive phosphorus (DRP), dissolved unreactive phosphorus (DUP) and particulate phosphorus (PP), which comprise total phosphorus (TP) in runoff from three rainfall simulation events. 71 Table 4.2 Results from Chapter 3 and 4, showing cost of treatments and total phosphorus (TP) lost from runoff box Chapter 3 DRP reduction stoichiometric ratio DRP reduction Cost per m3 slurry metal: TP % metal: TP % € m-3 87 88 74 88 1.11:1 0.93:1 10:1 2:1 83 86 69 67 1.90 7.40 8.80 10.20 7.00 Slurry Alum 0.98:1 PAC 0.98:1 Lime 5:1 FeCl2 2:1 a Taken from Chapter 3. b Chapter 4 stoichiometric ratio TP lost as % TP applied 7.70 0.46 1.05 1.16 2.20 Cost per kg P reduction P lost € kg P-1 kg P ha-1 66.70 91.10 111.00 61.00 2.90 0.17 0.40 0.44 0.19 The cost m-3 and cost effectiveness have been updated from Chapter 3 to reflect the slight change in ratio of metal:TP in the present runoff box study. c Laboratory grade aluminium chloride (Al2(SO4)3.nH2O) was used in Chapter 3. Commercially available commercial grade liquid poly-aluminium chloride was used in the present study. Note: All treatments were found to be significantly different to the control (p<0.001) in the Chapter 3 study. However, these were not significantly different to each other. In this study, all treatments were significantly different to the slurry-control. Alum and AlCl3 were significantly different to lime and FeCl2, but not to each other. (€1.00 is approximately equal to $1.37 or £1.59) There was no significant difference between TP in runoff water from grass-only (373 μg L-1) and alum treatments (506 μg L-1). However, there was a significant difference between grass-only and PAC (1,150 μg L-1) (p< 0.001), lime (1,270 μg L-1) and FeCl2 (2,400 μg L-1) treatments for TP (p< 0.001), with a less significant difference between grass-only and PAC (790 μg L-1) and Fe (1,730 μg L-1) for PP (p< 0.001). Therefore, alum was the best amendment at reducing TP and PP loss to runoff. Table 4.2 shows the TP lost in the runoff expressed as a percentage of the slurry applied. The TP losses from the control were in agreement with Preedy et al. (2001), who reported that between 6 and 8% of TP applied was lost to runoff. The TP in runoff from the grass-only treatment comprised approximately 47% DRP compared to 69% reported by Haygarth et al. (1998). This difference may be a result of scale effects or differences in experiment design. While chemical amendment of dairy slurry significantly reduced DRP, DUP, PP and TP in runoff water, the proportions of each fraction in runoff from alum, PAC and FeCl2 treatments were similar to the slurry-control (Figure 4.7). 72 100% 80% PP 60% DUP 40% DRP 20% 0% Slurry Alum PAC Lime FeCl2 Grass Figure 4.7 The average % of dissolved reactive phosphorus (DRP) dissolved unreactive phosphorus (DUP) and particulate phosphorus (PP), which comprise total phosphorus (TP) in runoff after three rainfall simulation events Suspended sediment was 162 mg L-1 for the grass-only treatment compared to 3,030 mg L-1 for the slurry-control (Figure 4.8). Alum resulted in the greatest reduction in SS (an average of 88% for the three rainfall events compared to the slurry-control) (p<0.001). There was no statistical difference in average FWMC of SS between alum, PAC (83% reduction) and lime (82%). All of the treatments resulted in SS concentrations in the runoff which were significantly greater than the grass-only treatment (p<0.005). 4.4.3. Metals in runoff water The average FWMC of Al, Ca and Fe for the 3 rainfall simulation events are shown in Figures 4.9, 4.10 and 4.11. The average concentrations of metals tested in runoff water for the 3 rainfall simulation events were greater for the slurry-control than the grass-only treatment. Aluminium concentrations increased from 60 to 91 µg Al L-1 (not statistically significant), Ca from 84 to 108 mg L-1 (p<0.01), and Fe increased from 71 to 151 µg L-1 (p=0.02, RS2). 73 5000 Suspended sediment (mg L-1) 4500 4000 3500 3000 2500 2000 1500 1000 500 0 1 2 Slurry 3 1 2 Alum 3 1 2 3 PAC 1 2 Lime 3 1 2 FeCl2 3 1 2 3 Grass Figure 4.8 Average flow-weighted mean concentrations of suspended sediment in runoff The FWMC of Al decreased for all treatments compared to the slurry-control (Figure 4.9). There was a significant treatment x event interaction (p<0.001) and differences between events within treatments and between treatments within events were tested. After multiple comparison adjustments, there were no statistically significant differences between treatments. There were some significant decreases to the RS3 event compared to RS1 and RS2 for the lime and slurry-control treatments (p =0.03 and p =0.006). The FWMC of Ca in runoff from all chemically amended slurry treatments was significantly greater than from the slurry-control and the grass-only treatment (p<0.01) (Fig. 4.10). The treatment by event interaction was significant and while no treatments were statistically different across all events, there were some differences between the grass treatment and both alum (p=0.02, RS1) and the slurry-control (p=0.02, RS2), and also between the FeCl2 and the slurry-control (p=0.02, RS2). 74 Flow weighted mean concentration of aluminium (Al) in runoff water (μg L-1) 250 200 150 100 50 0 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 Slurry Alum PAC Lime FeCl2 Grass Source Figure 4.9 Average flow-weighted mean concentrations of Al in runoff and rain water Flow weighted mean concentration of calcium (Ca) in runoff water (μg L-1) 300 250 200 150 100 50 0 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 Slurry Alum PAC Lime FeCl2 Grass Source Figure 4.10 Average flow-weighted mean concentrations of Ca in runoff and rain water 75 Flow weighted mean concentration of iron (Fe) in runoff water (μg L-1) 400 350 300 250 200 150 100 50 0 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 Slurry Alum PAC Lime FeCl2 Grass Source Figure 4.11 Average flow-weighted mean concentrations of Fe in runoff and rain water 4.5. Discussion 4.5.1. Slurry and amended slurry analysis The amendments examined significantly reduced WEP in amended slurry compared to the control. This was in agreement with previous studies (Dao, 1999; Dou et al., 2003). Lefcourt and Meisinger (2001) reported a 97% reduction in WEP of dairy cattle slurry when 2.5% by weight of alum was added in a laboratory batch experiment. Dao and Daniel (2002) added alum (810 mg Al L-1) and ferric chloride (810 mg Fe L-1) (compared to 1250 mg Al L-1 and 2280 mg Fe L-1 in this study) to dairy slurry and observed that slurry WEP was reduced by 66 and 18%, respectively. At higher application ratios of metal-to-TP, this study showed that greater reductions in WEP are achievable. The amendments also changed the pH of the slurry. Lime addition increased slurry pH significantly, resulting in a 25 and 30% reduction in NH4-N and TN of slurry following amendment and mixing (Table 4.1). This was similar to findings of a study by Molloy 76 and Tunney (1983), who reported an increase in pH to 7.8 and a 50% increase in NH3 loss when CaCl2 was added to dairy slurry. This loss in NH4-N was most likely due to NH3 volatilisation, as depending on the pH of a solution, NH4-N can occur as NH3 gas or the ammonium ion (NH4) (Gay and Knowlton, 2005). This reduces the fertiliser value of the slurry and increases NH3 emissions from slurry. Addition of alum, PAC and FeCl2 to dairy cattle slurry significantly reduced the pH, as expected. This phenomenon has been reported by a number of studies examining the use of amendments to reduce NH3 losses from dairy cattle slurry (Meisinger et al., 2001; Shi et al., 2001). Meisinger et al. (2001) reported a 60% reduction in NH3 loss from dairy cattle slurry when 2.5% by weight of alum was added in a laboratory batch experiment. In a field study, Shi et al. (2001) reported a 92% reduction in NH3 loss. Moore and Edwards (2005) have shown that chemical amendment improves yields due to increased N efficiency. Chapter 5 examines the impact of amendments on gaseous emissions and the risk of ‗pollution swapping‘, which must be considered when evaluating amendments for possible recommendations to legislators. 4.5.2. Water quality The DRP and TP concentrations in runoff water from grass only treatment was well in excess of the MAC of 30 μg DRP L-1 (Flanagan, 1990) and 25-100 μg TP L-1 (USEPA, 1986) for fresh waterbodies. This study reinforced the results of a micro-scale study (Chapter 3) at meso-scale and demonstrated that PAC is the most effective chemical amendment to reduce incidental DRP losses, with alum being most effective at reducing DUP, PP, TP and SS losses arising from land application of dairy cattle slurry. A limited number of runoff studies have been carried out with chemical amendment of dairy cattle slurry (Elliot et al, 2005; Torbert et al., 2005) and swine slurry (Smith et al., 2001a). Torbert et al. (2005) amended landspread composted dairy manure with ferrous sulphate, gypsum and lime (each at 3:1 metal-to-TP ratio) immediately prior to a 40-min rainfall event with overland flow equivalent to a rainfall intensity of 124 mm h-1. Ferrous sulphate reduced DRP loss by 77 66.3%, while gypsum and lime amendments increased DRP loss compared to control. Lime and gypsum were effective for a short time at the beginning of the event and the authors recommended that lime could be used in areas with infrequent and low volume runoff events. In the Torbert et al. (2005) study, amendments were surface applied to slurry immediately after slurry application and just before the first rainfall simulation event occurred. The differences between the results are likely due to a combination of the shorter contact time with lime before the first rainfall event and less mixing due to different amendment application methods used in each study. In a plot study, Smith et al. (2001a) amended swine manure with alum and AlCl3 at two stoichiometric ratios (0.5:1 and 1:1 Al: TP). Dissolved reactive phosphorus reductions for alum and AlCl3 at the lower ratio were 33 and 45%, respectively, with 84% for both amendments at the higher ratio, which was similar to reductions observed in the current study. The reductions in P losses in the present study were similar to the percentage reductions obtained in other incidental P loss mitigation studies. Hanrahan et al. (2009) reported that incidental TP and DRP losses were reduced by 89 and 65%, respectively, by delaying rainfall from 2 to 5 d after dairy cattle slurry application. This was in agreement with results of O‘Rourke et al. (2010). In a plot study, McDowell and Sharpley (2002b) applied dairy cattle slurry at 75 m3 ha-1 to the upper end of plots with lengths varying from 1 to 10 m. Increasing the distance from the location where dairy slurry was applied to the runoff water collection point was shown to reduce incidental P concentrations in overland flow by between 70 and 90% when plots were subjected to simulated rainfall with an intensity of 70 mm h-1. Therefore, as there are less expensive methods which can achieve similar reductions in incidental P losses, in future the focus of chemical amendment studies must be to find amendments to bind P in soil with the aim of reducing long-term P losses. In order to minimise the effect of the larger variation in the study control than in runoff from grass-only and amended slurry runoff boxes and to detect differences between treatments, the slurry-control was excluded from the statistical analysis of TP and PP. The reduction in TP and PP losses when alum, PAC and FeCl2 was added to slurry was a 78 result of a combination of precipitation and floc formation, which led to a decrease in SS loss in runoff water. In the case of lime addition, the reductions were a result of the formation of Ca-P precipitates. The average FWMC of TP for the slurry-control during the three rainfall simulation events was 8,390 μg L-1. This was similar to 7,000 μg L-1 reported by Preedy et al. (2001) in a rainfall simulation study to examine incidental P loss from dairy slurry. Measures such as increasing the time between slurry application and the first rainfall event are as effective as chemical amendment at reducing incidental losses of P. Chemical amendment immobilises soluble P in slurry applied to soil and could therefore be included as a low capital cost management tool to reduce farm P status and chronic P losses. The cost of chemical amendments in comparison to other treatment methods (e.g. transporting to other farms, AD, separation and composting) is likely to be the most significant factor in the future implementation of chemical amendments. Economies of scale were not considered in this study and this could considerably reduce costs. The cost of amendment, calculated after results of Chapter 3, based on the estimated cost of chemical, chemical delivered to farm, addition of chemical to slurry, increases in slurry agitation, and slurry spreading costs as a result of increased volume of slurry due to the addition of the amendments to slurry, is shown in Table 4.2. At the scale of the present study, alum and ferric chloride provide the best value in reducing on TP loss from slurry. These are preliminary estimates and if the cost of using these amendments as a mitigation measure is to be accurately calculated, then the optimum dosage for each amendment at field-scale needs to be determined. 4.5.3. Metals in runoff water Previous studies (Moore et al., 1998; Edwards et al., 1999) have reported that chemical amendment of poultry litter posed no significant risk of increased metal release to runoff water. The findings of the present study also validate this for chemical amendment of dairy cattle slurry. Moore et al. (1998) associated an increase in Ca release from alum treatment to a displacement of Ca in Ca-P bonds by Al. This is also likely to be the cause 79 for PAC and FeCl2 with Ca displaced by Al and Fe. The increase in Ca from the lime treatment was expected as a high rate of lime was applied. The FWMC of Fe (Figure 4.11) decreased for all treatments except alum, which increased Fe loss by 30% compared to the slurry-control; this was most likely a result of pH effect of alum, which increased the Fe solubility leading to higher Fe losses. There are acute (acute concentrations being short-term concentration and chronic being a long-term concentration) MAC (750 μg L-1) and chronic MAC (87 μg L-1) for Al in runoff (USEPA, 2009). The Al concentrations observed in the present study were below all MAC with the exception of slurry-control during RS2 and grass-only treatment in RS2, which exceeded chronic MAC. There is no MAC for Ca in water. Iron concentrations in runoff were all below the chronic MAC of 1,000 μg L-1 (USEPA, 2009). From previous studies, adverse effects are not expected due to alum amendment to manure. In a plot study, Moore el al. (1998) amended poultry litter with alum to examine the effect of alum amendment on runoff concentrations of metals. Alum treatment significantly reduced Fe in runoff. Runoff Al concentrations were not affected by treatment and Ca concentrations increased after treatment. Moore et al. (2000) also found Al loss from a small-scale catchment was unaffected by alum treatment. In order to determine the effect of long-term additions of alum to poultry litter, Moore and Edwards (2005) began a 20-yr study in 1995. The most significant findings of this study were that long-term land application of alum-amended poultry litter did not acidify soil in the same way as NH4-N fertilisers and that Al availability was lower from plots receiving alumtreated poultry manure than NH4-N fertiliser. McFarland et al. (2003) incorporated alum into soil prior to application of dairy dirty water and reported no difference in Al concentrations in runoff between control and alum amended plots. 4.6. Conclusions The results of this study demonstrate that chemical amendment was very successful in reducing incidental losses of DRP, TP, PP, TDP, DUP and SS from land-applied slurry. The results of the study demonstrate that PAC was the most effective amendment for 80 decreasing DRP losses in runoff following slurry application, while alum was the most effective for TP and PP reduction. Incidental loss of metals (Al, Ca and Fe) from chemically amended dairy cattle slurry was below the MAC for receiving waters. Future research must examine the long-term effect of amendments on P loss to runoff, gaseous emissions, plant availability of P and metal build-up in the soil. If amendments to slurry are to be recommended and adopted as a method to prevent P losses in runoff, the impact of such applications on slurry-borne pathogens, as well as pathogen translocation to the soil and release in surface runoff, needs to be addressed. The long-term effects on microbial communities in soil must also be examined. The results of this study show that even with chemical amendment, P concentration in runoff was above the MAC. Therefore, amendments may not be the best option for minimising incidental P losses, as timing of applications may be just as effective at controlling incidental P losses, and may be much more cost effective. However, chemical amendment immobilises soluble P in slurry and has the potential to reduce chronic P losses. The use of chemical amendments in combination with other mitigation methods such as grass buffer strips would likely increase the effectiveness of the measures. Future work should focus on using amendments to reduce P solubility in slurry to decrease P loss from high P soils by binding P in slurry once it is incorporated into the soil, thereby allowing farmers to apply slurry to soil without further increasing the potential for P loss. 4.7. Summary The agitator test (Chapter 3) identified amendments with the best ability to reduce P solubility in dairy cattle slurry. Chapter 4 has shown that these amendments can effectively reduce all forms of P in runoff in realistic conditions. The next step is to examine these amendments at field-scale. However, before these amendments are examined at field-scale, there is a need to examine their impact on GHG and potential pollution swapping. Chapter 5 details the results of an experiment designed to examine GHG and pollution swapping. These results allow feasibility discussion (Chapter 3) to be developed further to include GHG and pollution swapping. 81 Chapter 5 Effect of chemical amendment of dairy cattle slurry on greenhouse gas and ammonia emissions 5.1. Overview The previous two chapters examined the effectiveness and feasibility of amendments in reducing P solubility. This chapter considers the effect of chemical amendment of dairy cattle slurry on gaseous losses which, together with their impact on surface runoff, are critical in selecting most feasible amendments for recommendation to legislators. 5.2. Introduction Organic manure is a valuable fertiliser resource in terms of N, P, K and micronutrients. Losses of N and P to both groundwater and the atmosphere not only act as significant sources of pollution, but can represent significant losses in terms of fertiliser value (Lalor, 2008). Whilst the efficacy of the various slurry amendments on P sequestration efficiency is well quantified (Dao, 1999; Lefcourt and Meisinger, 2001; Dao and Daniel, 2002; Dou et al., 2003; Chapters 2 and 4), there is less information on their effects on gaseous emissions and pollution swapping. This study will allow the feasibility ranking to be further refined to take account of GHG emissions and pollution swapping. An experiment was designed to facilitate the measurement of NH3, N2O, CH4 and CO2 emission following land application of dairy cattle slurry (Figure 5.1). Charcoal was included as an additional treatment as there is a large body of work involving biochars being carried out at present and there is the potential in their use for P mitigation and GHG control. 82 1 Air stripped of ammonia before entering dynamic chamber after Misselbrook et al. (2005) 2 Sealed dynamic chambers with air flowing continuously 3 Acid traps used to measure ammonia volatilisation after Misselbrook et al. (2005) 4 Flow meters used to measure and regulate flow throughout the study 5 Pump used to create vacuum to draw air over slurry in dynamic chambers Figure 5.1 Photograph of dynamic chamber apparatus 5.3. Materials and Methods 5.3.1. Soil sample collection and analysis Intact soil samples were collected from a dairy farm in Athenry, Co. Galway (53°21‘N, 8°34‘ W). 120-mm-high, 100-mm-diameter Al coring rings were used to collect undisturbed soil core samples (n=18). Soil samples, taken to a depth of 100 mm below the ground surface from the same location, were air dried at 40°C for 72 h, crushed to pass a 2 mm sieve, and analysed for Morgan‘s P using Morgan‘s extracting solution (Byrne, 1979). Soil pH (n=3) was determined using a pH probe and a 2:1 ratio of deionised water-to-soil. Soil texture was determined by PSD (B.S.1377-2:1990a). Organic matter content of the soil was determined using the LOI test (B.S.1377-3; BSI, 1990b). The soil was a poorly-drained sandy loam (58% sand, 27% silt, 15% clay) with a Morgan‘s P of 22±3.9 mg P L-1, a pH of 7.45±0.15 and an OM content of 13±0.1%. 83 Historic applications of organic P from an adjacent commercial sized piggery led to high STP in the soil used in this study. 5.3.2. Dairy slurry collection and analysis Cattle slurry from dairy replacement heifers was taken from a dairy farm (53°21‘ N, 8°34‘ W) in County Galway, Republic of Ireland. Before sample collection, the storage tanks were agitated. Samples were transported to the laboratory in 10-L drums and stored at 4°C. Slurry and amended slurry pH was determined using a pH probe (WTW, Germany) and the WEP of slurry was measured at the time of land application after Kleinman et al. (2007). The TP of the dairy cattle slurry was determined after Byrne (1979). Potassium and Mg were analyzed using a Varian Spectra 400 Atomic Absorption instrument and analyses for N and P were carried out colorimetrically using an automatic flow-through unit. Ammoniacal nitrogen of slurry and amended slurry was extracted from fresh slurry by shaking 10g of slurry in 200 ml 0.1 M hydrochloric acid (HCl) on a peripheral shaker for 1 h and filtering through a No 2 Whatman filter paper. 5.3.3. Chemical amendment of slurry The six treatments examined in this study, selected based on results of Chapter 3 and 4, were: slurry-only (the study control) and slurry amended with (1) industrial grade alum (8% Al2O3, Al2(SO4)3.nH2O) (2) industrial grade PAC (3) analytical grade FeCl2 (4) lime (Ca(OH)2) and (5) charcoal. With the exception of charcoal (analytical grade activated charcoal used as biochar can vary depending on material from which it is made), the amendments were applied at the following stoichiometric rates determined from Chapter 3: alum 1.11:1 (Al: TP); PAC 0.93:1 (Al:TP); FeCl2 2:1 (Fe:TP); and lime 10:1 (Ca: TP). Charcoal was applied at a rate equivalent to 3.96 m3 ha-1. This corresponded to a rate above which DM of slurry would become too high to allow landspreading without adding water (Stan Lalor pers com, 2010). The amendments were added to the slurry and mixed rapidly using a blender immediately before simulated land application. A grass only background was also examined but values measured were very low compared to 84 emissions from slurry treated soil cores so these were excluded. Slurry and amended slurry were applied directly to the surface of the intact grassed soil at a rate equivalent to 26 kg TP ha-1 (33 m3 slurry ha-1). Immediately after application, the chambers were sealed and the air flow through the system was started and maintained for 168 h. 5.3.4. Measurement of ammonia The dynamic chamber used in this experiment was based on a design used by Misselbrook et al. (2005). Eight chambers were connected in parallel (Figure 5.2). Air was drawn through the system via a vacuum pump, with air flow through each chamber regulated at 5.1 L min-1. This was to ensure that the number of headspace exchanges per minute was such that the emission of NH3 would not be affected by small differences in flow rates between chambers (Kissel et al., 1977). Figure 5.2 Diagram of apparatus used to measure ammonia emissions 85 Prior to entering each chamber, the ammonia contained in the ambient air was immobilised using an acid trapping method. The air was drawn over the soil surface using a vacuum pump (VTE 10 VACCUM PUMP, Irish Pneumatic Service LTD, Ireland) and gas mass flow meters were used to regulate and measure air flow (Cole-Parmer, Hanwell, UK). The chambers comprised the same 200-mm-diameter Al cores used to collect the grassed soil samples, fitted with a polypropylene lid and base (Figure 5.3). The samples were saturated for 48 h and then allowed to drain for 48 h. During this time, the surfaces were covered to avoid evaporation losses. After approximate field capacity was achieved, the chambers were sealed at the base using silicon grease to ensure an air-tight seal. Each treatment was applied to the grassed-soil surface and a lid was fitted to each chamber. Each chamber had four inlet and outlet ports to ensure good mixing of air within the chamber (after Misselbrook et al., 2005). During the dynamic phase, the cores were attached to the dynamic chamber for 168 h. During this time, air was drawn through the chambers over the surface of the treated soil and through acid traps, which were used to measure NH3. Figure 5.3 Dynamic chamber 86 5.3.5. Measurement of CH4, N2O and CO2 Air samples were drawn from the head space of the ammonia volatilisation chamber (AVC) and analysed for CH4, CO2 and N2O using a photo-acoustic-analyser (PAA; INNOVA 1412, Lumasense Inc, Denmark) (Figure 5.4). The majority of NH3 volatilisation arising from spreading of slurry occurs in initial 48 h after spreading (Gary Lanigan pers com, 2011), while N2O and CH4 losses take place over a much longer time period (Gary Lanigan pers com, 2011). Therefore, it was only necessary to use the AVC for the first 168 h and then continue CH4, CO2 and N2O sampling for a further 10 d. During the first 168 h (during which time NH3 was measured), the chamber was disconnected from the AVC apparatus and the inlet and outlets were connected to the PAA for 6 min at t= -1 (1 h before treatment), 0, 2, 6, 24, 48, 72, 96, 144, 168. After 168 h, NH3 measurement was discontinued and the Al cores, containing intact soil samples, were removed from the apparatus and incubated in the laboratory. During this time, a portable cap was fitted to each chamber and the PAA was used to measure fluxes at t = 9, 11, 13, 15 and 17 d. The mass of the sample, and therefore water content, was kept constant throughout the experiment by periodically adding deionised water to the surface of the soil samples. 5.3.6. Statistical analysis Data (Appendix D) were checked for normality and homogeneneity of variance by histograms, qq plots, and formal statistical tests as part of PROC UNIVARIATE procedure of SAS (SAS, 2004). The data were analysed using the PROC GLM procedure (SAS, 2004). The linear model included the fixed effects of treatment and, with the exception of slurry pH, CH4 and CO2, data were logarithmically transformed prior to analysis. A multiple comparisons procedure (Tukey) was used to compare means. 87 Figure 5.4 Photograph of PAA during carbon dioxide, methane and nitrous oxide measuring period 5.4. Results 5.4.1. Slurry and amended slurry results The slurry had TN of 4430±271 mg L-1, TP of 1140±76 mg L-1, TK of 4480±218 mg L-1 and a pH of 7.5±0.05. The slurry TP and TK remained relatively constant, while the WEP was lowered significantly by all chemical amendments (Table 5.1). Alum, FeCl2 and PAC addition reduced slurry pH from approximately 7.5 to 5.4, 6.7, and 6.4, respectively (p<0.005). The pH of alum-amended slurry was significantly different to all other treatments, while FeCl2 and PAC were not significantly different to each other. Addition 88 of lime increased slurry pH to 12.2 (p<0.001), while charcoal did not have a significant effect on slurry pH. Table 5.1 Dairy cattle slurry and amended dairy cattle slurry properties Treatment DM (%) Slurry-control 10.5 (0.04) Alum 9.4 (0.16) Lime 8.2 (0.29) FeCl2 10.1 (0.22) PAC 9.6 (0.28) Charcoal 12.57 (0.45) (Standard deviation in brackets) pH 7.5 (0.05) 5.4 (0.12) 12.2 (0.12) 6.7 (0.06) 6.4 (0.05) 7.3 (0.4) WEP (g/kg DM) 1.81 (0.112) 0.008 (0.002) 0.014 (0.001) 0.017 (0.001) 0.011 (0.002) 1.78 (0.23) 5.4.2. Ammonia Alum (p<0.001), FeCl2 (p<0.005), PAC (p<0.005) and charcoal (p<0.01) reduced NH3 emissions by 92, 54, 65 and 77% compared to the slurry-control, while lime increased emissions by 114% (p<0.001). Lime amendment resulted in the loss of 84% of TAN applied. Alum, PAC, FeCl2 and char were not statistically different to each other. The NH3 emissions from untreated and chemically amended slurry, expressed as a percentage of TN and NH4-N in the applied slurry, are shown in Figure 5.5. Ammonia release from slurry for all treatments followed a Michaelis-Menten response curve, with the majority of emissions occurring within the first six hours following application. With the exception of the lime treatment, chemical amendment of slurry prior to land application increased the time for half of ammonia losses to occur (T0.5). Alum (p<0.005), FeCl2 (p<0.05), PAC (p<0.006) and charcoal (p<0.05) increased T0.5, compared to the slurry-control, from 1.5 to 4.1, 3.5, 4.3 and 3.4 h, respectively (p<0.05). The T0.5 of lime-amended slurry was not significantly different to the slurry-control. Cumulative ammonia release from untreated slurry was 40% of TAN. 89 Ammonia emission, % of total N applied 60 Slurry Alum FeCl2 Lime PAC Charcoal 50 40 30 20 10 0 0 30 60 0 30 60 90 Time (hours) 120 150 120 150 Ammonia emission, % of NH4-N 100 90 80 70 60 50 40 30 20 10 0 90 Time (hours) Time after slurry application (hours) Figure 5.5 Cumulative ammonia emissions from untreated and chemically amended slurry expressed as a percentage of total nitrogen in slurry and ammoniacal nitrogen in slurry 90 5.4.3. Nitrous oxide Cumulative N2O emissions of dairy cattle slurry increased when amended with alum (p<0.2) and FeCl2 (p<0.2) by 202 and 154 % compared to the slurry-control. Lime (p<0.5), PAC (p<0.01) and charcoal (p<0.01) resulted in a reduction of 44, 29 and 63% in cumulative direct N2O loss compared to the slurry-control. In this study, nitrous oxide emissions following land application of dairy cattle slurry were observed to increase from 0.18 g N2O-N ha-1 h-1 to a peak of 4 g N2O-N ha-1 h-1 at 24 h post application (Figure 5.6). Emissions of N2O from alum were similar in magnitude and temporal dynamics to those from the slurry-control. Ferric chloride addition resulted in no increase in N2O emissions until the 72 h sampling event, and a peak flux of 4.7 g N2O-N ha-1 h-1 was measured at 96 h. Lime, PAC and charcoal addition resulted in much lower emissions, with peak emissions occurring after 24-48 h. 5.4.4. Carbon dioxide In general, addition of amendments to slurry did not significantly affect soil CO2 release during the study (Figure 5.7), with cumulative emissions for the period ranging from 320 – 380 kg CO2 ha-1 (Figure 5.8). However, significant reductions in CO2 efflux were observed upon charcoal addition, with an 84% reduction in cumulative CO2 emissions observed (p<0.05). Immediately following land application of dairy cattle slurry and chemically amended slurry, there was generally a peak in CO2 emissions followed by a steady release for the duration of the study. The lime amended slurry behaved differently to the other treatments and the slurry-control, and acted as a CO2 sink immediately after land application. However, the cumulative emissions were similar to PAC and FeCl2 treated slurry. 91 13 Slurry only Alum Ferric chloride Lime 11 9 7 5 3 1 -1 -3 N2O g (N2O-N ha-1 h-1) 13 11 9 7 5 3 1 -1 -3 13 PAC Charcoal 11 9 7 5 3 1 -1 -3 -50 50 150 250 350 -50 50 150 250 350 Time from land application of dairy cattle slurry (hours) Figure 5.6 Nitrous oxide emissions from slurry and amended slurry in chambers (Mean ± standard error) 92 14 Slurry only 12 Alum Ferric chloride Lime PAC Charcoal CO2 (kg CO2-C ha-1 h-1) 10 8 6 4 2 0 -2 -4 -50 0 50 100 150 200 250 300 350 400 Time from land application of dairy cattle slurry (hours) Figure 5.7 Carbon dioxide emissions from slurry and amended slurry in chambers. (Mean ± standard error) 1000 Global warming potential ( kg CO2-eq ha-1) Methane Carbon dioxide 800 600 400 200 0 -200 Slurry only Alum Ferrous Lime PAC Charcoal Treatment Figure 5.8 Cumulative carbon dioxide emissions from chambers for duration of study. (Mean ± standard error) 93 5.4.5. Methane emissions Methane emissions increased from -0.18 g CH4-C ha-1 h-1 to 94 g CH4-C ha-1 h-1 upon application of dairy cattle slurry (Figure 5.9). These levels decreased rapidly to approximately 7 g CH4-C ha-1 h-1 by 48 h and remained relatively constant until the 312 h sampling event. Following this, methane losses were much more variable. There was a similar trend for all of the amended slurries applied with an initial increase in losses followed by a rapid decrease and then steady release for the duration of the study. All of the amendments examined reduced the initial peak in CH4 emissions compared to the slurry-control (p<0.0001). Lime (p<0.05), PAC (p<0.08) and FeCl2 (p<0.09) reduced cumulative CH4 emissions compared to the slurry-control by 134, 121 and 99%, respectively. Alum, charcoal and the slurry-control were not significantly different to each other. 120 Slurry only Alum Ferric chloride Lime PAC 300 350 Charcoal 100 80 CH4 g CH4-C ha-1 h-1 60 40 20 0 -20 -40 -60 -50 0 50 100 150 200 250 400 Time from land application of dairy cattle slurry (hours) Figure 5.9 Methane emissions from slurry and amended slurry in chambers. (Mean ± standard error) 94 5.4.6. Impact of amendments on global warming potential Chemical amendment of dairy cattle slurry has been proposed as a possible P mitigation measure for the control of P solubility in dairy cattle slurry (Chapters 3 and 4). In order to access the pollution swapping potential of the treatments, all emissions were expressed in CO2 equivalents. Cumulative direct and indirect N2O emissions from slurry and amended slurry in the chambers during the study are shown in Figure 5.10. Global warming potential (CO2 equivalents) 1000 900 800 700 600 500 Indirect nitrous oxide 400 Nitrous oxide 300 200 100 0 Slurry only Alum Ferrous Lime PAC Charcoal Treatment Figure 5.10 Nitrogen cumulative emissions (Nitrous oxide and indirect emissions resulting from ammonia losses) expressed in CO2 equivalents. (Mean ± standard error) Indirect N2O emissions were calculated based on the assumption that all the NH3 would be re-deposited within a 2 km radius of the point of application, which allowed use of an emission factor of 1% (IPCC, 2006). Alum, FeCl2, lime and PAC have no significant effect on the sum of the cumulative direct and indirect N2O emissions, while charcoal reduced total N2O emissions from by 69% compared to the slurry-control (p<0.01). The total N2O emissions from charcoal treated slurry – with the exception of PAC - were 95 statistically different to slurry (p<0.01), alum (p<0.01), FeCl2 (p<0.001), lime (p<0.001) treatments. Cumulative carbon dioxide and methane emissions are shown in Figure 5.8. Charcoal reduced total cumulative CO2 and CH4 emissions compared to the control (p<0.001) and was significantly different to alum (p<0.001), FeCl2 (p<0.05), lime (p<0.01) and PAC (p<0.05). All gases measured have been expressed in CO2 equivalents and are plotted in Figure 5.11. Amendment of slurry with charcoal significantly reduces greenhouse warming potential (GWP) following land application of dairy cattle slurry (p<0.001). In this study, there was no significant effect of any amendment of slurry on GWP caused by land application of dairy cattle slurry, with the exception of charcoal. Global warming potential (CO2 equivalents) 1400 1200 Carbon dioxide Indirect nitrous oxide Nitrous oxide Methane 1000 800 600 400 200 0 -200 Slurry only Alum Ferrous Lime PAC Charcoal Figure 5.11 Cumulative carbon dioxide (CO2), indirect nitrous oxide (N2O), direct N2O and methane (CH4) measured during the study expressed in CO2 equivalents. (Mean ± standard error) 96 5.5. Discussion 5.5.1. Ammonia emissions Ammonia volatilisation from dairy cattle slurry following land application is controlled by: humidity, temperature, wind speed at the time, method of application, and the degree of infiltration of the slurry into the soil (Søgaard et al., 2002, Sommer et al., 2003, Sommer et al., 2006). In addition, slurry pH, DM and TAN content greatly influence the rate and amount of NH3 volatilisation (Smith et al., 2000; Misselbrook et al., 2000; Meisinger et al., 2001). It is estimated that between 60-80% of TAN applied can be lost during broadcast land spreading of cattle slurry, particularly during the first 12 h post application (Pain et al., 1989, Hyde et al., 2003). In the present study, cumulative NH3 loss from land applied dairy cattle slurry was 22.6 kg NH3-N ha-1, with approximately 39% of NH4-N applied lost in initial 24 h; this was equivalent to 15% of TN applied. With the exception of lime, all amendments used reduced NH3 losses compared to the slurry-control. This reduction was expected as chemical amendments, such as alum, have been used extensively in the USA to reduce NH3 emissions from poultry litter (Moore et al., 1999) and from dairy cattle slurry (Table 5.2). Meisinger et al. (2001) reported a 60% reduction in NH3 loss from dairy cattle slurry when 2.5% by weight of alum was added in a laboratory batch experiment. In a field study, Shi et al. (2001) reported a 92% reduction in NH3 loss. The results of the present study were in agreement with previous findings for alum, PAC and FeCl2, and the ammonia abatement by alum, PAC and FeCl2 was primarily due to reductions in pH (ie. N was held in the ammonium form). The large reductions in ammonia emissions associated with charcoal addition (74%) may have been due to both ammonia gas and ammonium ion adsorption, as biochar can act as a cation exchange medium (Asada et al., 2002). During pyrolysis of woody material for biochar production, thermolysis of lignin and cellulose occurs, exposing acidic functional groups, such as carboxyl groups. This has been shown to result in an 80-100% removal efficiency for ammonia gas (Oya and Iu, 2002; Iyobe et al., 2004). Biochar addition 97 during the composting of poultry litter reduced ammonia losses by 64%, even though pH increased (Steiner et al., 2010). As a result, the mechanism was thought to be due to the adsorption of ammonium ions as opposed to the immobilization of ammonia (Steiner et al., 2008). In addition, biochar has also been found to reduce N leaching by 15% due to adsorption of the ammonium ion predominantly by cation exchange (Ding et al., 2011). Table 5.2. Summary of amendments used to reduce ammonia emissions in previous studies Reference Meisinger et al. (2001) Kai et al. (2007) Chemical Amount added Slurry Study % NH3 pH to slurry type type reduction slurry alum 2.5% (w/w) Dairy Lab 60 4.5 zeolite 6.25% (w) 55 7.8 H2SO4 5 kg m-3 70 6.3 Swine Field Comments Simulated storage experiment Farm scale storage and application Smith et al. (2001a) Alum 0.75% (v/v) Swine Plot 52 6-week study Molloy and Tunney, FeSO4 0.8 g to 25 g Dairy Batch 81 Batch scale experiment MgCl2 0.8 g to 25 g 23 CaCl2 0.8 g to 25 g 50 7.8 Alum 4500 kg ha-1 92 5.98a CaCl2 4500 kg ha-1 71 6.99a HCL 240 m Eq CaCl2 300 m Eq (1983) Shi et al. (2001) Husted et al. (1991) a Dairy Field Dairy Applied to surface of feedlot 90 Lab 15 pH referred to is the pH of soil and slurry mixture Lime increased slurry pH to 12.2 and increased the NH3 loss compared to the slurrycontrol. Molloy and Tunney (1983) reported an increase in pH to 7.8 and a 50% decrease in NH3 loss when CaCl2 was added to dairy cattle slurry. This suggests that, although there may be potential to reduce NH3 loss using Ca-compounds such as lime, it is not feasible at application rates high enough to reduce P solubility in dairy cattle slurry. There was a linear relationship between slurry pH at time of application and NH3 loss from slurry and amended slurry in this study (R2=0.86) (Figure 5.12). This would indicate that the change in slurry pH was the main process responsible for the reduction in NH3 loss from dairy cattle slurry. In addition, there was a significant relationship (R2=0.98) between slurry pH at the time of application and the log of the T0.5 (Figure 5.12). This 98 would indicate that if large NH3 losses do not occur in the short-term after land spreading, the potential for loss is significantly reduced i.e. chemical treatments are not just delaying NH3 loss, but mitigating it completely. In addition to environmental problems caused by NH3 losses, such losses reduce the nutrient value of the fertiliser and increase NH3 emissions from slurry. The value of N lost via ammonia and N2O emissions from the slurry-control for the duration of the study amounted to approximately €0.63 per m3 slurry applied based on cost of €1.10 per kg N (Stan Lalor pers com, 2011). Alum, FeCl2, PAC and charcoal increased the fertiliser value of slurry by €0.56, €0.32, €0.41 and €0.48 per m3 of slurry compared to the slurrycontrol. 1.2 y = 6.9236x - 36.497 R² = 0.8593 50 40 1 Log10 T0.5 Cumultive NH3 emissions 60 30 20 10 0.6 y = 0.05x + 0.4857 R² = 0.985 0.4 0.2 0 -10 0.8 0 0 5 10 15 0 5 10 15 Slurry pH Slurry pH Figure 5.12 Relationship between slurry and amended slurry pH at time of application and (a) cumulative NH3 emissions and (b) and log of time for half of ammonia emissions to occur (T0.5) 5.5.2. Nitrous oxide Land application of agricultural wastes results in an increase in N2O emissions from soil (Velthof and Oenema, 1997). Nitrous oxide is of environmental importance as it contributes to global warming and the depletion of the ozone layer. It is produced by nitrification and denitrification processes. Nitrous oxide emissions are influenced by: soil 99 moisture status, soil temperature; soil nitrate content and organic carbon content (Velthof et al., 2002). It was hypothesised that any reduction in NH3 loss would result in a concomitant increase in N2O in soil due to higher soil N available for nitrification/denitrification. Alum amendments were shown to double cumulative N2O losses compared to the slurry only treatment, whilst lime addition resulted in a decrease in N2O emissions. Although N2O emissions of the treatments examined were not significantly different to the control, alum and charcoal were significantly different to each other (p<0.01). The low direct N2O losses associated with lime addition were merely due to the fact that most of the available mineral N had been already lost during volatilisation. Ammonia volatilisation can also lead to indirect N2O emissions as the majority of ammonia volatilised in the field is re-deposited within 2 – 5km via wet and dry deposition, and a proportion (1%) is re-emitted as N2O (IPCC, 2006). When these indirect losses were calculated, lime addition accounted for an increase in indirect N2O emissions from 283 g N2O ha-1 for the slurry-control to 606 g N2O ha-1. These results highlight the need to account for all gaseous N losses as an analysis of ammonia or N2O in isolation would give skewed results. In terms of abating total N emissions, biochar was the most effective amendment reducing total N2O losses by 63%. There is currently sparse information on the effect of biochar on N2O emissions. Some laboratory studies have indicated that biochar may reduce N2O by increasing soil aeration and hence reduce water-filled pore space (Yanai et al., 2007). Alternatively, if pH is increased upon charcoal addition, this may induce a shift towards total de-nitrification to N2, thus reducing N2O (Clough and Condron, 2010). 5.5.3. Carbon emissions The majority of amendments had little effect on soil CO2 respiration, demonstrating that the amendments neither stimulated nor retarded soil microbial processes. The reduction in CO2 emissions associated with charcoal was surprising considering that a C source was added. Previous studies on charcoal application to organic manures have shown an 100 increase in C emissions in the short-term (Steiner et al., 2010), while biochar addition to soils have also indicated a simulation of soil microbial respiration (Wardle et al. 2008). After land application, CH4 emissions are of minor importance compared to NH3 and N2O emissions (Wulf et al., 2002a, b). Methane is produced mainly by microbial decomposition of OM under anaerobic conditions. The highest efflux was for untreated slurry and alum, immediately post manure application would indicate CH4 formation during manure storage, as there would not be sufficient time for its formation in the soil. It is produced during slurry storage and shortly after slurry application, after which time the OM is oxidised to CO2 and H2O as aerobic conditions prevail. Initial CH4 emissions in the following few hours most likely originate from CH4 contained in the manure diffusing from the viscous layer, while subsequent emissions were likely to be produced during the degradation of labile carbon compounds (Chadwick et al., 2000; Sherlock et al., 2002). Kasimir-Klemedtsson et al. (1997) reported similar base-line CH4 soil emission levels of 1.1 kg CH4-C ha-1 day-1 (3.01 g CH4-C ha-1 day-1) from Swedish cereal cropped soils, while Rodhe et al. (2006) recorded similar peak CH4 emissions of approximately 75 g CH4-C ha-1 day-1 immediately post application of cattle slurry to grassland. Chadwick and Pain (1997) also reported high emission levels following pig and dairy manure application to grassland soil in laboratory experiments. 5.5.4. Impacts of pollution swapping Chemical amendment of dairy cattle slurry provides an opportunity to immediately reduce P solubility in dairy cattle slurry and could be included as a low capital cost management tool to reduce P solubility in manure and reduce farm P status in the shortterm, as other management practices come into effect. This study allows for the effect of chemical amendment on gaseous emissions to be incorporated into the feasibility analysis of Chapter 3. The ranking system, determined in Chapter 3, was based on effectiveness, efficiency, potential barriers to use and cost of implementation. A new feasibility analysis was developed to include the results of this study and to give recommendations for the best amendment to mitigate DRP losses with the least potential for pollution swapping. 101 The results of this feasibility analysis are shown in Table 5.3. Charcoal was excluded as there is insufficient data on P sequestration potential to date. In order of decreasing feasibility, the amendments were ranked from best to worst as follows: PAC, alum, FeCl2 and lime. Therefore, the amendments selected for recommendation for further study are, from best to worst: PAC, alum and lime. Ferric chloride was excluded due to risk of stability of Fe-P bonds in soil. Although there are similar concerns with lime, it is currently added to soil in Ireland to reduce acidity in soils and for this reason, it was decided to recommend lime over FeCl2. Table 5.3 Summary of feasibility of amendments (Adapted from Chapter 3). Marks for feasibility and pollution swapping are from 1 to 5. 1 = best 5 = worst. Chemical Alum Ratio used Chapter 3 Feasibility score P Pollution swapping Combined feasibility 0.98:1 Al: P 1 5 6 Notes Risk of effervescence Risk of release of H2S due to anaerobic conditions and reduced pH Cheap and used widely in water treatment AlCl3 (PAC) 0.98:1 Al: P 2 2 4 Reduced ammonia emissions No risk of effervescence (Smith et al., 2004) AlCl3 increased handling difficulty Expensive FeCl2 (FeCl3) 2:1 Fe: P 3 4 7 Reduced ammonia emissions Potential for Fe bonds to break down in anaerobic conditions Increased release of N2O Reduced ammonia emissions Ca(OH)2 5:1 Ca: P 4 3 7 Increased NH3 loss Strong odour Hazardous substance Charcoal 1 Potential to reduce P solubility limited work to date Improve soil microbial health Reduced GHG emissions Reduced ammonia emissions 5.6. Conclusions This study showed that P mitigating amendments can result in pollution swapping. The amendments selected for recommendation for further study are, from best to worst, PAC, 102 alum and lime. Charcoal has excellent potential to reduce GHG losses caused by the land application of dairy cattle slurry. There is a need to develop biochars which are efficient in sorbing P and can improve soil quality and reduce GHG emissions. In addition, at the current cost of treatment, the increase in fertiliser value of the slurry due to some treatments is not sufficient to offset the cost of treatment. In this study, there was no significant effect of any amendment of slurry on GWP caused by land application dairy cattle slurry, with the exception of charcoal 5.7. Summary It is critical that when evaluating the feasibility of these amendments, ‗pollution swapping‘ is considered. This study has identified the need for a field study to examine the effect of the amendments on gaseous losses. In addition, there is a need to examine the effect of amendments using different soil types and wetting and drying regimes. Chapter 6 details the results of a runoff study following the landspreading of chemically amended slurry at field-plot scale and Chapter 7 examines the impact of chemically amended slurry on soil properties over a 9-mo study duration. 103 Chapter 6 6.1. Plot-scale rainfall simulation study Overview This plot-scale runoff experiment was designed to develop an understanding of the performance of amendments under more realistic conditions. In this experiment, natural drainage occurred, which did not occur in the runoff box experiments. The plot and runoff characteristics such as soil volumetric water content, time to runoff and runoff volume were also measured to investigate potential adverse effects of amendments on runoff at a larger scale. 6.2. Introduction The present study examines the effect of chemical amendment of dairy cattle slurry with alum, PAC and lime on both P and N losses to runoff, whereas plot and runoff-box experiments which have examined chemical amendment of dairy cattle slurry to date have focused almost entirely on P losses. Although P is the limiting nutrient in freshwater systems (Correll, 1998), N losses also pose a significant risk to water quality (Johnes et al., 2007; Vitousek et al., 2009). When chemical amendments are used to reduce P losses, it is important that the effects of amendments on N losses through runoff, leaching and volatilisation are also examined to ensure that ‗pollution swapping‘ does not occur. The experimental set-up of the present study tested the efficacy and feasibility of using a variety of chemical amendments in the field, but still under controlled conditions. The objectives of this study were to investigate the effect of chemical amendment of dairy cattle slurry on: (1) average FWMC of DRP, DUP, PP and TP (2) average FWMC of 104 NO3, NO2 and NH4-N; and (3) plot and runoff characteristics such as soil volumetric water content, time to runoff and runoff volume. 6.3. Materials and Methods 6.3.1. Study site This study was conducted on a 0.6 ha isolated plot on a beef farm located at Teagasc, Johnstown Castle, Environmental Research Centre (latitude 52º 17‘N, longitude 6º 29‘W), in the southeast of Ireland (Figure 6.1). This area has a cool maritime climate, a mean annual precipitation of 1002 mm (effective rainfall from between 400 to 500 mm), and a mean annual temperature of 9.6°C (Ryan and Fanning., 1996). The location of 25 experimental plots within the 0.6 ha site was determined by: topography/slope, soil texture/drainage, depth to watertable and soil analysis. For textural analysis, 100 mmdeep soil samples (n=3) were taken from a 1 m2 area at the top, middle and bottom of the plot (Figure 6.1). Soil texture was determined using PSD analysis after B.S.1377-2:1990 (BSI, 1990a). An electromagnetic conductivity and resistivity survey was also used to infer textural and drainage characteristics. The site had undulating topography with a 6.7% slope along its length and an average slope of 3.6% across the site. The topsoil was classified as a Haplic Stagnosol (Rachel Creamer pers com, 2011). Combining PSD and geophysical data together, textural classes ranged from a fine loam-to-clay loam within the plot. The top of the plot comprised gravelly clay with pockets of silty/clayey gravel underlain by silt/gravel (20 to 26 mSm-1) and was relatively well-drained compared to the lower part of the site, which comprised silt/clay and was poorly drained (>26 mS m-1). The median perched watertable depth in three piezometers (top, middle and bottom) was 0.6 m below ground level (bgl) on site. The nutrient status of the soil at these locations was determined using Morgan‘s P extractant (Morgan, 1941) and, together with K and Mg, are presented in Table 6.1. The soil was classified as P index 3 (>5.1 mg L-1 for grassland soils in accordance with SI 610 of 2010) throughout the site, meaning that it represented minimum risk of P loss to water. 105 Soil pH (n=3) was determined using a pH probe and a 2:1 ratio of deionised water to soil (Table 6.1). Figure 6.1 Map of study site showing ground elevation, topography, slope, soil conductivity, groundwater flow direction, location of subplots and of groundwater wells. The location selected was of uniform topography, soil classification, texture and drainage characteristics. In addition, it was in the location of the site with the highest water table 106 and had relatively constant soil nutrient status. Once the study location was selected, each plot was isolated and instrumented with a runoff collection channel (Figure 6.1). Table 6.1 Soil pH, Morgan‘s extractable P, K and Mg, sand silt, clay fractions, and textural class of soil used in this study. The location of the piezometers is illustrated in Figure 6.1 Position a Piezometer No. pH Morgan‘s P mg L-1 P indexa K Mg Sand Silt Clay mg L-1 mg L-1 % % % Textural Class Lower 1 5.8 2.6 2 173 171 52 30 18 Sandy Loam Middle 2 5.9 3.2 3 140 195 47 36 18 Sandy Silt Loam Upper Average Std dev 3 6.1 5.9 0.2 3.6 3.1 0.5 3 96 136 38.6 151 172 22 44 47.7 4 36 34.0 3.5 21 19.0 1.7 Clay Loam P index is the classification system used in Ireland to classify soil P status of soils (Schulte et al, 2010b) The treatments were randomly assigned to twenty-five plots (0.9 m by 0.4 m) which were orientated along a line. Composite soil samples (100 mm) were taken from each plot and WEP was determined (n=3). Soil pH and Morgan‘s P were determined, and the slope of each plot was surveyed. Soil pH (5.96±0.22) was consistent across the 25 plots (Table 6.2). Soil test P (4.95±1.75 mg P L-1) and WEP (7.24±4.52 mg P kg-1) appeared to vary across the site, with lower values observed close to the location of the piezometers. Figure 6.2 shows photographs of site setup, plot installation and runoff collection troughs. 6.3.2. Slurry analysis Cattle slurry was taken from the dairy farm at the Teagasc, Environmental Research Centre, Johnstown Castle, in August of 2010. The storage tanks were agitated and slurry samples were transported to the laboratory in 25-L drums. Slurry samples were stored at 4°C prior to land application. Slurry pH was determined using a pH probe (WTW, Germany). The TP of the dairy cattle slurry was determined after Byrne (1979). Total potassium, TN and TP were carried out colorimetrically using an automatic flow-through unit (Varian Spectra 400 Atomic Absorption instrument). The WEP of slurry and amended slurry was measured at the time of land application after Kleinman et al. (2007), and NH4-N of slurry and amended slurry was extracted by shaking 50 g of slurry in 1 L 107 of 0.1 M HCl on a peripheral shaker for 1 h and filtering through No. 2 Whatman filter paper at the time of application. The results of the slurry analysis are shown in Table 6.3. The slurry sample was typical of slurry found on farms in Ireland (SI 610 of 2010). The slurry TN, TP, NH4-N and TK were constant with the exception of the lime-treated slurry, which had high TN, TP and TK. The WEP of slurry was lowered significantly by all alum and PAC amendments. Alum addition reduced the slurry pH from approximately 7.1 to 6.5, while lime addition increased the slurry pH to 8.8. Table 6.2 The average slope for each block, soil pH, water extractable phosphorus (WEP), Morgan‘s extractable P, potassium (K), and magnesium (Mg) before application of treatments. Block Slope pH WEP % g kg P -1 K mg L -1 mg L Mg -1 mg L-1 1 4.7 (1.5) 6.1 (0.22) 5.5 (2.3) 3.25 (0.82) 49.6 (5.7) 123 (4.5) 2 3.2 (1.8) 5.9 (0.14) 7.5 (3.3) 4.9 (1.9) 55.2 (8.2) 150 (5.7) 3 2.3 (1.9) 6.06 (0.26) 11.4 (5.9) 6.9 (0.83) 59.5 (7.8) 184 (6.7) 4 3.3 (1.7) 6.02 (0.22) 6.8 (5.1) 6.07 (0.85) 58.4 (6.57) 230 (1.2) 5 4.4 (1.1) 5.77 (0.16) 5 (3.6) 3.59 (0.72) 60.8 (4.5) 218 (5.7) Average 3.58 5.97 7.24 4.94 56.7 181 Std deviation 0.97 0.13 2.53 1.6 4.5 45 (Standard deviations in brackets) Table 6.3 Slurry DM, pH, water extractable phosphorus (WEP), total nitrogen (TN), total phosphorus (TP) and total potassium (TK) and average concentrations of NH4- N (n=5) Treatment DM Slurry 9.1 (0.54) Alum 9.6 (0.58 PAC 9.42 (0.64) Lime 9.4 (0.38) Average 9.38 Std dev 0.2 (Standard deviations in brackets) pH 7.1 (0.62) 6.5 (0.44) 6.9 (0.47) 8.8 (0.67) 7.325 1.01 WEP TN TP TK NH4+-N g kg-1 mg L-1 mg L-1 mg L-1 mg L-1 3.19 (0.37) 0.0028 (0.001) 0.0074 (0.008) 2.48 (0.99) 1.4 1.7 3960 (741) 4410 (590) 3980 (1280) 5010 (725) 4340 492 1240 (145) 1260 (190) 1200 (270) 1390 (150) 1270 82.2 5170 (870) 5210 (640) 4330 (1290) 5610 (840) 5080 538 1200 (260) 1160 (270) 1180 (290) 1210 (300) 1190 22.2 108 Grass cut and plots isolated Plot during micro-plot installation Plot isolation Runoff collection. Shield removed to allow photo to be taken Figure 6.2 Plot set up and runoff collection photograph 6.3.3. Treatments The five treatments examined in this study were: (1) grassed soil-only, (2) slurry-control (3) industrial grade liquid alum (Al2(SO4)3.nH2O), comprising 8% Al2O3 (4) industrial grade liquid poly-aluminium chloride hydroxide (PAC) (Aln(OH)mCl3n-m) comprising 10% Al2O3 and (5) lime (Ca(OH)2). Amendments were added to the slurry and mixed rapidly by shaking in 2-L containers immediately prior to land application. Two days 109 before the first rainfall simulation, slurry and amended slurry were applied directly to the surface of the grassed soil. Slurry application rates were equivalent to 33 m3 slurry ha-1 (42 kg TP ha-1), the rate most commonly used in Ireland (Coulter and Lalor, 2008). Amendments were applied at stoichiometric ratios determined in Chapter 3. Alum was applied at a rate of 1:1 (Al: TP); poly-aluminium chloride at a rate of 0.85:1 (Al: TP); and lime at a rate of 3.9:1 (Ca: TP). Appendix E shows photographs of amended slurry. 6.3.4. Rainfall simulation Two identical portable multi-drop ‗Amsterdam type‘ rainfall simulators, described by Bowyer-Bower and Burt (1989), were used in this study. These rainfall simulators have been used on similar permanent grassland sites and soil types (Kurz et al, 2006; Kramers et al., 2009; O‘Rourke et al, 2010). The rainfall simulators were designed to distribute rainfall over a surface area of 0.5 m2 and were calibrated to deliver rainfall at an intensity of 11 mm h-1. In order to ensure the absence of edge effects, the study plots – each measuring 0.36 m2 in area - were positioned directly under the rainfall simulator. The plots were isolated using 2.2 m-long, 100 mm-deep rigid plastic sheets, which were pushed 50 mm into the soil to isolate three sides of the plot. The runoff collection channel was placed at the bottom of the slope (Figure 6.1). Plots were orientated with longest dimension in the direction of the slope (average 3.6 %). The runoff collector comprised a polypropylene plastic U-shaped channel piece, which was cut in half and wedged against the soil at a depth of approximately 25 mm below the soil surface (Figure 6.1). A 400 mm-wide edging tool was used to ensure a good seal between soil and collector. The plots were left uncovered for two weeks prior to first rainfall simulation to allow natural rainfall to wash away soil disturbed by inserting the isolators. The grass on all plots was clipped to a height of 50 mm two days prior to the first simulated rainfall event. Figure 6.3 shows one of the rainfall simulators used in this study. Land application of treatments was staggered over three days and applied in blocks to allow for the first rainfall event (RS1) two days after land application of slurry. The second event (RS2) was 10 d after the original application (t = 12 d) and the third (RS3) after 28 d (t = 30 d). 110 Rainfall simulations were carried out between 17th September 2010 and 18th October 2010 (Figure 6.4). Wind shield used to prevent rain from blowing View of rainfall simulator before rainfall starts rain Figure 6.3 Photographs of rainfall simulator The allocation of the rainfall simulators was randomised between blocks and alternated for treatments. Runoff was judged to occur once 50 ml of water was collected from the runoff collection channel and the time from start of rainfall simulation to runoff of 50 ml being the time to runoff (TR). Samples were collected every 5 min for RS1, and every 10 min for RS2 and RS3. Surface runoff was collected for 30 min once runoff commenced to allow the FWMC to be calculated (Kurz et al., 2006). Rainfall simulator input water had the following average concentrations: 0.05 mg NH4-N L-1, 4.61 mg NO3-N L-1, 0.001 mg DRP L-1 and 0.004 mg TP L-1; 0.00 mg NH4-N L-1, 4.53 mg NO3-N L-1, 0.004 mg DRP L-1 and 0.00 mg TP L-1; 0.00 mg NH4-N L-1, 4.51 mg NO3-N L-1, 0.00 mg DRP L-1 and 0.00 mg TP L-1 for RS1, RS2 and RS3 respectively. 111 Figure 6.4 Natural rainfall and average depth of simulated rainfall received by the plots for each event The volumetric water content of soil in each plot was measured immediately prior to each rainfall simulation event using time domain reflectrometry (Delta-T Devices Ltd., Cambridge, UK) (Figure 6.5), which was calibrated to measure resistivity in upper the 50 mm of the soil in each plot. Three readings were taken in each plot and the average was calculated. 112 Figure 6.5 Photo of the measurement of volumetric water content of soil using time domain reflectrometry Immediately after collection, runoff water samples were filtered through 0.45µm filter paper and a subsample was analysed colorimetrically for DRP, total oxidized nitrogen (TON), NO2-N and NH4-N using a nutrient analyser (Konelab 20, Thermo Clinical Labsystems, Finland). Nitrate was calculated by subtracting NO2-N from TON. A second filtered sample was analysed for TDP using acid persulphate digestion. Unfiltered runoff water samples were analysed for TP with an acid persulphate digestion. Particulate phosphorus was calculated by subtracting TDP from TP. The DRP was subtracted from the TDP to give the DUP. All samples were tested in accordance with the Standard Methods (APHA, 1995). 6.3.5. Statistical analysis The structure of the data (Appendix F) set was a blocked one-way classification (treatments) with repeated measures over time (events). The analysis was conducted using Proc Mixed in SAS software (SAS, 2004) with the inclusion of a covariance model to estimate the correlation between events. A large number of covariates were recorded, including measurements on the simulators. For each analysis, this set of covariates was screened for any effects that should be included in an analysis of covariance. The 113 interpretation was conducted as a treatment x time factorial. Comparisons between means were made with compensation for multiple testing effects using the Tukey adjustment to p-values. Significant interactions were interpreted using simple effects before making mean comparisons. In order to ensure that STP variation did not affect the experiment, STP was included as a variable in the statistical analysis. Slurry concentration, which was of much greater significance in terms of P concentrations in runoff following slurry application, was uniform within each block. 6.4. Results 6.4.1. Phosphorus (FWMC of DRP, DUP, PP and TP) The average FWMC of DRP, DUP and PP, which comprise TP in runoff, are shown in Figure 6.6. During RS1, alum (p<0.05) and PAC (p<0.001) reduced DRP in runoff water compared to the slurry-control by 95 (0.13 mg P L-1) and 98% (0.05 mg P L-1), respectively. Alum and PAC, at p<0.02 and p<0.01, also reduced TP concentrations in runoff from the plots during RS1 by 92 (0.61 mg P L-1) and 83% (1.37 mg P L-1), respectively, compared to the slurry-control. None of the amendments examined reduced FWMC of DRP or TP losses to below the MAC during the study. The FWMC of TP and DRP for the alum-amended plots did not show any discernable trend, although the average reduction in FWMC, compared to the slurry-control, over the three rainfall events, for TP and DRP was 81 and 77%, respectively. Comparatively, the FWMC of TP continued to reduce over the three rainfall events for the PAC-amended plots, although the DRP concentrations were still over the MAC for all runoff events. Alum-treated slurry and PAC-treated slurry were not significantly different to each other throughout the study. However, there was a significant difference in FWMC of TP in runoff during RS1 between soil-only (p<0.05), alum (p<0.05) and PAC (p<0.01) compared to the slurry-control. 114 12 PP DUP DRP 10 TP (mg L-1) 8 6 4 2 0 1 2 3 1 Slurry 2 3 1 Alum 2 3 1 PAC 2 3 1 Lime 10 2 3 Soil PP DUP DRP TP (mg L-1) (Log scale) 1 0.1 0.01 1 2 Slurry 3 1 2 3 1 Alum 2 3 PAC 1 2 Lime 3 1 2 3 Soil Treatment Figure 6.6 Average flow-weighted mean concentrations of dissolved reactive phosphorus (DRP), dissolved un-reactive P (DUP) and particulate P (PP) comprising total P (TP) for three rainfall simulation events, and maximum allowable concentrations (MAC) in waterways. 115 The addition of lime increased the average FWMC of DRP and TP over the three rainfall events, compared to the slurry-control, by 82 and 38%, respectively. This increase in P loss as a result of lime amendment may be due to the pH of the lime-amended slurry. Penn et al (2011) found that in order for Ca-phosphate bonds to remain stable, the pH must remain in a range of 6.5 to 7.5. The average pH of the soil on the site was 5.97 and the pH of the lime-amended slurry was 8.8 at the time of application. Chapter 3 showed that the pH of lime-amended dairy cattle slurry increased in the first 24 h following land application. The slurry pH was too high for Ca-P bonds to be stable during RS1 and when the slurry and soil interacted and reached equilibrium, the soil pH was lower than the optimal pH for the formation of Ca-P bonds. This may be why reductions were not observed during RS2 and RS3. 6.4.2. Nitrogen The average FWMC of NO3-N, NO2-N and NH4-N in runoff water for grassed soil-only plots for the three simulated rainfall events were 3.98 mg NO3-N L-1, 0.03 mg NO2-N L-1 and 0.22 mg NH4-N L-1 compared to 3.6 mg NO3-N L-1, 0.02 mg NO2-N L-1 and 0.82 mg NH4-N L-1 for the slurry-control (Figure 6.7). The NO3-N and NO2-N concentrations in runoff water from soil only plots were not in excess of the MAC of 11.3 mg NO3-N L-1 (EEC, 1988) and 0.1 mg NO2-N L-1 (OJEC, 2006) for salmonidal rivers. The addition of amendments had no significant effect on NO3 concentration in runoff water. Ammonium concentrations in runoff from plots receiving alum-amended dairy cattle slurry, averaged across the rainfall events, were in excess of lower drinking water standards of 0.2 mg NH4-N L-1, but below the upper limit of 4 mg NH4-N L-1 (EEC, 1989). The alum amendment increased NH4-N in runoff by 84% from 2.4 mg NH4-N L-1 in the slurry-control to 4.3 mg NH4-N L-1 during RS1, while PAC reduced NH4-N in runoff by 80% (0.4 mg NH4-N L-1) compared to slurry-control during RS1. Lime had no significant effect on NH4-N concentrations in runoff water. The peak in NH4 loss during RS1 was a result of the application of dairy cattle slurry, which was high in NH4. 116 12 NO3 10 NO2 NH4-N N (mg L-1) 8 6 4 2 0 1 2 Slurry 3 1 2 Alum 3 1 2 3 PAC 1 2 3 1 Lime 2 3 Soil Treatment Figure 6.7 Average flow-weighted mean concentrations of ammonium nitrate (NH4-N), nitrite (NO2-N) and nitrate (NO3-N) for three rainfall simulation events, and maximum allowable concentrations (MAC) in waterways. 6.4.3. Time to runoff, soil volumetric water content and runoff volume The rainfall intensity, volume of runoff (converted to equivalent depth), time from start of rainfall application to start of runoff event, and volumetric water content of the soil at the start of each rainfall simulation are shown in Figure 6.8. Almost 90% of all rainfall applied drained away or leached through the soil, with 7.8% of water applied to soil-only being collected as runoff from the upper 25 mm of the soil surface, 9% for the slurrycontrol, 9.4% for alum-amended slurry, 15% for PAC-amended slurry and 14.3% for lime-amended slurry. The runoff volumes were not statistically different to each other. 117 6 RS3 15 10 5 0 Soil Slurry Aum 140 Time to runoff (min) RS2 Runoff volume (mm) RS1 120 RS2 RS3 3 2 1 0 Soil Slurry Aum PAC Lime Mean 60 RS3 RS2 4 PAC Lime Mean RS1 RS1 5 Volumetric water content (%) Intensity (mm hr-1) 20 RS1 RS2 RS3 50 100 40 80 30 60 20 40 10 20 0 Soil Slurry Aum PAC Lime Mean 0 Soil Slurry Aum PAC Lime Mean Figure 6.8 Average rainfall intensity, runoff volume, time to runoff and soil volumetric water content for the first (RS1), second (RS2) and third (RS3) rainfall events. There was no statistical evidence of any effect of rainfall simulator on the experimental outcome. The average intensity for each rainfall simulation event for the two simulators was 10±1.8 mm h-1 and 10.7±1.93 mm h-1, respectively. Rainfall intensity and soil water content did not have a significant effect on TR, runoff volume, or P and N losses. Covariate analysis of the logarithmic of the TR showed that event (p<0.001) and slope (p<0.01) of plots affected TR. 118 6.5. Discussion 6.5.1. Phosphorus (FWMC of DRP, DUP, PP and TP) Throughout the study, the DRP concentrations in runoff water from soil-only plots were in excess of the MAC of 0.03 mg DRP L-1 for surface waterbodies in Ireland (Flanagan, 1990). The average FWMC of TP for the soil only treatment was in excess of water quality limit of 0.025-0.1 mg TP L-1 (USEPA, 1986) for surface water in the USA. The concentrations in runoff from the slurry-control plots were also all in excess of the MAC for DRP and TP for the duration of the study. However, the buffering capacity of water means that the concentration of the water in a surface waterbody will not be as high as the concentration of runoff, provided runoff from slurry flows over soil which has not received dairy cattle slurry (McDowell and Sharpley, 2002b). The results of the present study show that chemical amendments can be used to reduce P solubility in dairy cattle slurry and thus reduce P loss to a surface waterbody. Alum and PAC reduced P losses significantly compared to the slurry-control. Possible reasons for this failure to achieve runoff concentrations below the MAC may be insufficient chemical amendment of slurry, rainfall intensity and insufficient contact time to achieve adsorption of P. Incidental P losses accounted for the majority of P losses from the slurry-control plot during the study, with approximately 75% of DRP, 72% of DUP, 94% of PP and 83% of TP losses, measured over the three rainfall events, occurring during RS1. While incidental losses were significantly reduced in the alum and PAC-amended plots, the effect of amendments on chronic loss of P from the plots was not clear as differences in runoff concentrations during RS3 and were not statistically significantly to slurry control. The results show that even in low P Index soils, there is risk of DRP concentrations, which are in excess of the MAC in runoff, entering drains. In a similar plot study with simulated rainfall applied at 25 mm h-1, Kruz et al. (2006) observed an average FWMC of DRP of 0.99 mg L-1 from soil with a Morgan‘s P varying between 5 mg P L-1 and 7 mg P L-1. These concentrations are all similar to the soil only treatment in this study. 119 The results in this study were similar to previous work (Preedy et al., 2001; Kleinman and Shapley, 2003; Hanrahan et al., 2009). Kleinman and Sharpley (2003) applied dairy cattle slurry to grassed runoff boxes at 50 kg TP ha-1. Runoff boxes were subjected to simulated rainfall at 70 mm h-1 three days after application, and DRP in runoff was 3.2 mg DRP L-1. We have therefore shown that even when slurry was applied within guideline application rates, concentrations of P in runoff were still in excess of limits. In practice, runoff from fields receiving slurry will pass through a buffer area and undergo dilution before it enters a waterway. This means that the concentrations measured in this paper were higher than the actual concentration of the water that would enter the waterway if these treatments were used in practice. Timing of slurry application and incorporation of slurry may be a much more feasible way to reduce incidental P losses. 6.5.2. Nitrogen On a low permeability soil, infiltration of N is unlikely and at this location N will predominantly be lost in runoff to rivers. Dairy cattle slurry is high in NH4-N, which may explain the high NH4-N in runoff during RS1. The reduction in NH4 concentrations in runoff between RS1 and RS2 across all treatments, including the slurry-control, was likely due to nitrification occurring in the soil following slurry application, and interaction with the soil. Nitrification occurs when microbes use enzymes to convert NH4 to NO2 and then NO3 to obtain energy (Ketterings et al., 2011). This also explains why there was so little NO2 in the runoff water in comparison to NO3. Land application of dairy cattle slurry resulted in an increase in NH4-N compared to soil only. Smith et al. (2001b) reported similar findings. Smith et al. (2001b) added dairy cattle slurry at a rate 75 m3 ha-1 to grassed plots and reported soluble N (NH4-N+NO3-N) concentrations ranging from 2 mg L-1 to 14 mg L-1, which was comparable to the average FWMC of soluble N observed in this study (6.3 mg L-1). Nitrite losses were not significant and were equivalent to approximately 1.9% of NO3 for most samples. Land application of dairy cattle slurry did not have a significant effect on NO3 loss to runoff water; this was in agreement with results from Smith et al. (2001b). Alum increased NH4- 120 N loss during first rainfall event, while PAC reduced NH4-N loss compared to the slurrycontrol. These results indicate that chemical amendments could potentially increase N in runoff from dairy cattle slurry. It is critical that the potential for ‗pollution swapping‘ is examined when evaluating chemical amendment of dairy cattle slurry. In particular, the effects of any amendments on GHG emissions must be examined. Under the 1997 Kyoto Protocol of the United Nations Framework Convention on Climate Change (UN, 1998), participating nations agreed to publish national inventories of anthropogenic emissions of several GHG and to reduce future emissions below 1990 levels. In Ireland, agricultural activities were responsible for approximately 26% of total GHG emissions in 2008 (McGettigan et al., 2010) and account for virtually all NH3 emissions, with animal manure alone responsible for 92% of NH3 emissions (EPA, 2010). While NH3 is not a GHG, it contributes to acidification of soils, atmospheric pollution, and the eutrophication of surface and ground water systems (Goulding et al., 1998). An estimated 5% of global N2O emissions results from the conversion of NH3 into N2O in the atmosphere (Ferm, 1998). In addition to gaseous N losses (Amon et al., 2006), agricultural activities, such as land application of dairy cattle slurry, contribute to the production of NH3 and GHG, such as CO2, N2O (Ellis et al., 1998) and CH4 (Chadwick et al., 2000). Therefore, any chemical amendments which alter slurry properties may have an effect on GHG emissions. 6.5.3. Rainfall intensity, soil volumetric water content, time to runoff and runoff volume Land spreading of dairy cattle slurry at high rates may result in sealing of the soil surface by slurry solids. Smith et al. (2001b) reported a 16% increase in runoff volume compared to soil-only control when dairy cattle slurry was applied to the soil surface at 40 m3 ha-1. This is similar to an 11.5% increase in runoff volume observed in the present study, this increase was not, however, statistically significant. Chemical amendments of slurry appeared to increase runoff volume compared to the slurry-control, but the differences in runoff volume were not statistically significant. The rainfall simulation event was found 121 to have the greatest impact on runoff volume (p<0.05). There was a difference between plots, but the differences were not statistically significant. There was no statistically significant effect of treatment on runoff or TR. This indicated that the effect of amendment on any surface sealing which may have occurred was minimal. However, the lack of a relationship between soil water content and runoff properties may be a result of scale effects. The soil around the plots received no rainfall; this may also have resulted in an artificially high TR. In a similar plot study, Kleinman et al. (2006) examined the role of rainfall intensity and hydrology in nutrient transport via surface runoff and observed that despite significant differences in runoff generation processes (volume of runoff and TR), the concentrations of DRP in runoff were related to the STP of the grassed soil. Similar results were observed in the present study, however the DRP concentrations were dependent on the WEP of the slurry applied and not STP of the soil. Although amendments increased runoff at plot-scale, the effect of such an increase at field-scale cannot be fully known. There is potential that if runoff increased at a larger scale, increased erosion and loss of PP could occur. The variation observed in runoff has significant implications for comparing the results of this work with field-scale studies. Potential scale effects which must be considered include: (1) dilution due to different runoff volumes and TR (2) differing soil texture/permeability in between plots and (3) length of collection period, as the FWMC of the various measured water quality parameters may be artificially high since the water samples were not collected after rainfall stopped. 6.5.4. Outlook for future implementation of chemical amendment of dairy cattle slurry as a management practice for high P soils This study demonstrated that PAC was the most effective chemical amendment to reduce incidental DRP losses from dairy cattle slurry, with alum being most effective at reducing DUP and TP losses. Alum and PAC significantly reduced P losses, particularly in RS1, 122 while lime resulted in increased P losses and is not a suitable amendment at the rates examined in this study. The estimated cost of chemical amendment, calculated in Chapter 3, and based on the estimated cost of chemical, chemical delivery to farm, addition of chemical to slurry, increases in slurry agitation, and slurry spreading costs as a result of increased volume of slurry, increases the cost of land application from approximately Є1.90 m-3 for slurry only to Є6.5 m-3 for alum-, Є7.60 m-3 for PAC-, and 4.90 m-3 for lime-amended slurry. The TP lost from slurry-control plots during the study period had an approximate P fertiliser value of Є5.48 ha-1 compared to Є0.82 ha PAC reduced the value of P lost to Є1.45 ha -1 -1 lost from grass-only. Alum and and Є2.50 ha -1, respectively, while lime increased the value of TP lost to Є14.7 ha -1. The value of TP applied to plots receiving dairy cattle slurry and un-amended slurry was Є82.7 ha-1. Chemical amendment could be used in strategic areas (e.g. on farms with surplus P) to reduce P solubility in manure and P transfer to a surface and ground waters, whilst allowing farmers to utilise other nutrients in slurry on farms with high STP. In certain U.S states (Arkansas, Alabama, Tennessee and South Carolina), alum amendment of poultry litter is used as a standard conservation practice (Moore and Edwards, 2005). At present, there is no provision for a licence to landspread any of these amendments in Europe and if chemical amendment were to be used, a licensing system would have to be introduced by the relevant bodies. The plant availability of P in chemically amended manure is a major concern for stakeholders. Moore and Edwards (2005) has shown that chemical amendment improves yields due to increased N efficiency. In addition, in this study, chemical amendment is proposed for use to reduce P solubility where farmers have a short-term P surplus, and is recommended for strategic use within a catchment. Therefore, it should not be used in a site with low STP. Further work is required to access the long-term availability of P bound in Al bonds and if STP would decline as a result of chemical amendment of dairy cattle slurry prior to land spreading. 123 6.6. Conclusions The results of this plot-scale study validated results from micro-scale and meso-scale studies conducted in the laboratory. Treatment was not found to have a significant effect on time to runoff or volume of runoff. When compared to the slurry-control, alum and PAC reduced DRP by 95 and 98%, respectively, in runoff following RS1. Alum and PAC also reduced TP losses during RS1 by 85 and 92%, respectively. Lime increased P losses compared to the slurry-control. Addition of amendments had no significant effect on NO3-N in runoff water. Alum and lime increased the FWMC of NO2-N in runoff by 120 and 114% compared to the slurry-control. Alum amendment increased NH4-N in runoff by 84% compared to the slurry-control, while PAC reduced NH4-N in runoff by 80% compared to the slurry-control. Lime had no effect on NH4-N concentrations in runoff water. Alum amendment significantly increased average FWMC of NH4-N in runoff water during the first rainfall event after slurry was applied. This indicates that amendment on a large scale could increase soluble N losses and that large scale disposal to land may pose a problem. 6.7. Summary At the scale of the present study, alum and PAC provide the best value in reducing the TP loss from slurry; however, they are still very expensive. The next step is to examine the effects of long-term use of these amendments at field-scale and to quantify their effect on plant availability of P and GHG emissions. In addition, there is a need for a much greater examination of pollution swapping of N, with a focus on transfer of N to groundwater via leaching. Chapter 7 will examine the impact of chemically-amended slurry on soil WEP, plant available P and soil pH over a study with duration of 9 months. 124 Chapter 7 The long-term impact of the addition of chemically amended dairy slurry on phosphorus content and pH of five soil types 7.1. Overview In this chapter, the impact of chemically amended dairy slurry application to land on soil WEP, plant available P and soil pH was examined across 5 different soil types in Ireland. 7.2. Introduction A number of studies have examined the effect of chemical amendments on reducing P solubility in slurry (Dao, 1999), reducing P solubility in soil and slurry mixtures (Dao and Daniel, 2002), and reducing P in runoff from soils receiving amended slurry (Chapter 4). With the exception of Kalbasi and Karthikeyan (2004), there has been little research on the effect of chemical amendments on long-term P dynamics in soil following application of chemically amended dairy cattle slurry. Kalbasi and Karthikeyan (2004) examined three silt loam soils with different STPs in an incubation experiment conducted over a 24mo period. Kalbasi and Karthikeyan (2004) amended the soils with either untreated dairy manure, alum-treated dairy manure, ferric chloride-treated dairy manure, or lime-treated dairy manure. Results showed the effect of chemical amendment depended on treatment type, P application rate and background STP. Kalbasi and Karthikeyan (2004) concluded that more work was needed to investigate the effects of soils varying in physical and chemical characteristics. 125 7.3. Materials and methods 7.3.1. Soil collection and analysis Soils were selected from the upper 100 mm of 5 sites to represent some common soil types used in dairy farming in Ireland (Figure 7.1). The 5 soils collected were in the optimum range (5.1-8 mg L-1) of STP for productive grasslands with the exception of soil from Site C (Table 7.1), which was P deficient, and the peaty soil (soil E), which had a high STP. The peat soil was included as there is a particular risk of P loss from peat soils as they have poor capacity to store P (Cummins and Farrell, 2003) and could represent a critical source if P was applied in excess of agronomic requirements of crops. Fay et al. (2007) reported that 50% of mineral and organic soils had respective STPs lower than 6.4 mg L-1 and 9.3 mg L-1 in the upper 100 mm. Soils with different texture, OM, and pH were selected to test the effectiveness of the amendments in a variety of conditions. The selected soils give an indication of the stability of metal-phosphate bonds formed as a result of chemical amendment in a wide variety of conditions. Laboratory analysis was conducted to characterise the soil used in this study. The soil was air dried and crushed to pass a 2 mm sieve. Sub-samples were taken, dried at 40 °C for 72 h, and analysed for Morgan‘s P using Morgan‘s extracting solution (Morgan, 1941). Soil WEP (100:1 deionised water: soil) was determined after McDowell and Sharpley (2001). Soil pH (n=3) was determined using a pH probe and a 2:1 ratio of deionised water-to-soil. Particle size distribution was determined using B.S.1377-2:1990 (BSI, 1990a) and OM of the soil was determined using the LOI test (B.S.1377-3; BSI, 1990b). The results are presented in Table 7.1. Soil pH (n=3) was determined using a pH probe and a 2:1 ratio of deionised water-to-soil. 7.3.2. Slurry collection and analysis Dairy cattle slurry from dairy replacement heifers was taken from a farm (53°18‘ N, 8°47‘ W) in County Galway, Republic of Ireland, in Summer (June), 2010. The storage 126 tanks were agitated and slurry samples were transported to the laboratory in 10-L drums. Slurry samples were stored at 4°C prior to testing. Slurry pH was determined using a pH probe (WTW, Germany). The TP of the dairy cattle slurry was determined after Byrne (1979). Total potassium was analyzed using a Varian Spectra 400 Atomic Absorption instrument, and analyses for TN and TP were carried out colorimetrically using an automatic flow-through unit. The slurry application used in this experiment was based on an application rate of 33 m3 ha-1, which is common practice in Ireland (Coulter and Lalor, 2008). In order to facilitate randomisation, the same slurry application rate was selected for all soils. Amendment application rates to reduce soluble P in slurry were based on the results of Chapter 3. Figure 7.1 Site locations shown on map of Ireland 127 The slurry characterisation is shown in Table 7.2. The pH of slurry decreased for each of the acidifying amendments and increased for lime. The slurry sample was typical of slurry found on farms in Ireland (SI 610 of 2010). The slurry TN, TP, NH4-N and TK were relatively constant with the exception of the lime-treated slurry, which had high TN, TP and TK. Alum, PAC and FeCl3 addition reduced the slurry pH from approximately 7.2 to 5.1, 5.7 and 5.4 (p<0.001), respectively, while lime addition increased slurry pH to 12 (p<0.001). 7.3.3. Incubation experiment This 9-mo incubation study comprised six treatments, conducted in triplicate (n=3), at a fixed temperature of 11°C on: (1) soil only (to take account of the effects of incubation) (2) soil mixed with dairy cattle slurry (the study control); and soil mixed with dairy cattle slurry, which was amended with either (3) alum (4) lime (5) PAC, or (6) FeCl3 (In this study FeCl3 was used instead of FeCl2 as FeCl3 is the most commercially available form). First, 100 g samples of air dried soil, passed through a 2 mm sieve, were placed in 0.5-L containers. A volume of deionised water required to achieve 50% approximate field capacity was added and mixed with the soil using a spatula. Soil container capacity (CC), which is an approximate measurement of field capacity, was determined for each soil after Bond et al. (2006). To determine approximate field capacity, 100g of air-dried soil was placed in a container (with holes in the bottom) and saturated with deionised water. The container was then covered with para-film (perforated to allow air to circulate) and allowed to drain for 48 h through the drainage ports in the bottom of the container. It was then dried at 105° C and reweighed. This difference in weight was the CC (kg water kg-1 soil). 128 Table 7.1 Soil physical and chemical properties. Site Soil A Soil B Soil C Soil D Soil E Coordinates 52°07' N,8°16' W 52°17' N,6°31' W 52°17' N,6°31' W 53°21'N, 8°34' W 54°04' N,8°52' W Location Cork Wexford Wexford Galway Sligo Soil texture Sandy loam Clay loam Clay loam Silty loam Peat soil (na) Sand content % 56.2 (1.1) 51.8 (4.2) 37.8 (1.1) 15 (1.4) - Silt content % 25.8 (1.3) 28.1 (4.9) 31.1 (1.0) 72 (1.1) - Clay content % 18 (2.4) 20.1 (2.2) 31.1 (2.1) 13 (1.2) - 7.2 (1.2) 6.2 (2.1) 2.7 (0.9) 3.2 (1.5) 42.5 (4.5) 7.9 (0.6) 7.8 (0.26) 6.7 (0.5) 13.3 (0.23) 77.4 (0.2) Water extractable phosphorus mg kg Organic matter content % -1 Soil pH Potassium Magnesium Lime requirement of soil 6.1 (0.85) 5.7 (0.08) 6.5 (0.02) 5.1 (0.04) 5.6 (0.05) mg L-1 136 (5.4) 248 (2.9) 106 (1.1) 102 (6.1) 126 (6.4) -1 217 (9.1) 377 (19.4) 225 (2.1) 124 (2.9) 527 (48.7) 2 (0.6) 5 (0.3) XLS 3 (0.3) 12 (0.3) 5.8 (0.34) 5.7 (0.1) 2.6 (0.2) 5.1 (0.42) 24.6 (0.2) 3 3 1 3 4 675 (32) 634 (12) 539 (8) 825 (43) 2110 (59) 1.29 1.15 1.08 0.93 0.27 mg L t ha -1 Soil test phosphorus (Morgan‘s) mg L P Indexa Indexa Container capacity Soil bulk density -1 kg water kg soil -3 kg m -1 (Standard deviations in brackets), XLS: no lime requirement; aP Index: soils in Ireland ranked based on risk of P loss (Index 1 being low risk and 4 being the highest); 129 Table 7.2 Slurry properties Treatment Rate metal to TP Slurry DM pH % TN mg L TP -1 mg L TK -1 mg L-1 10.45 (0.78) 7.2 (0.34) 4860 (425) 1140 (93) 3110 (254) Alum 1.5:1 (Al:TP) 10.1 (0.35) 5.1 (0.35) 4660 (201) 1120 (19) 2840 (167) Lime 16:1 (Ca:TP) 13.8 (0.17) 12 (0.25) 3590 (459) 944 (79) 2620 (430) PAC 1.4:1 (Al:TP) 9.9 (0.35) 5.7 (0.4) 5320 (379) 1280 (154) 3060 (617) FeCl3 1.5:1 (Fe:TP) 11.4 (0.69) 5.4 (0.1) 5020 (283) 1180 (84) 3100 (153) (Standard deviation in brackets) The bulk density of each soil used in this study was determined based on the volume of 100g of sieved soil occupied in a container after field capacity was achieved (Table 7.1). Following this, slurry, or amended slurry, was added and mixed thoroughly (using a spatula) before being compacted to volume which was determined based on bulk density of soil and volume of slurry applied and water added. A packer was custom made (Figure 7.2) to compress soil to the approximate height. This height was determined based on soil bulk density, volume of water added and volume of slurry added (if added). First, the soil, slurry and deionised water were mixed in the container. The height of the stop blocks required to achieve appropriate bulk density was selected and placed beside the container The mixture was then compacted to an appropriate bulk density. The packer was then removed and cleaned using deionised water and drying paper before being used again. Figure 7.2 Schematic of packer used to achieve approximate bulk density 130 The amendments were applied at a stoichiometric rate based on the TP of the slurry (Table 7.2). The mineral soils examined have a mean bulk density of 1.12 ± 0.15 g cm-3 in the containers used to calculate field capacity and for the purpose of selecting slurry application rate, it was assumed that land applied slurry only interacts with the upper 20 mm of soil. Studies have shown that the STP in the upper 20 mm of grassland soils tends to be higher than for the equivalent depth in tillage soils receiving the same manure. This is due to the absence of tilling, which ploughs the nutrients into the soil (Andraski et al., 2003). Although the peat had a significantly different bulk density, it was decided to apply the same rate to the peat. The containers were covered with para-film. Throughout this study, water was added intermittently to ensure that approximately 50% field capacity was always maintained. After 1, 3, 6 and 9 mo, the DM and WEP of the wet soil was first determined. The remaining soil sample was air dried and crushed to pass a 2 mm sieve. Sub-samples were taken, dried at 40 °C for 72 h, and analysed for soil pH and Morgan‘s P using Morgan‘s extracting solution. 7.3.4. Statistical analysis The data (Appendix G) were analysed as a factorial design with soil type, month and treatment as factors. All interactions were examined. Soil type was a blocking effect in this structure, but its interactions with the randomised factors were of interest. The interactions were interpreted in the first instance by testing simple effects and then making comparisons of means, with adjustment for multiplicity of testing. The GLIMMIX procedure of SAS 9.2 was used to fit the analysis model. This procedure allowed the addition of heterogeneous variance structures and a number of options for examining a large number of means. Residual checks were made to check the assumptions of the analysis method. 131 7.4. Results 7.4.1. Water extractable phosphorus There was a significant interaction between soil type, month and treatment for WEP (p<0.001). The WEP of incubated soil samples at each sampling time is shown in Figure 7.3. The WEP of the soil-only treatments for the four mineral soils examined was lower after 1 mo of incubation than the WEP of the soil before the start of the experiment. This was in agreement with Kalbasi and Karthikeyan (2004) and Penn and Bryant (2006). This was likely due to the effect of drying and re-wetting, and breaking down of soil as a result of sieving (Penn and Bryant, 2006). In general, the WEP of the soil-only treatment did not vary significantly during the study for soils A, B and E. The WEP of soil C was significantly higher at the 6 mo sampling event than at any other time in the study. The WEP of soil D increased significantly between mo 1 and 3, and stayed steady for the remainder of the study. In contrast, the WEP of the peat soil increased initially as a result of incubation; however, there was no significant variation during the study. Addition of slurry increased the WEP of soil compared to the soil-only treatment for all soils. This was in agreement with result of other studies (Kalbasi and Karthikeyan, 2004; Murphy, 2007). However, in general, these increases were not statistically significant. The WEP of soil A, when amended with slurry, was significantly different to the soilonly treatment at the 3 mo sampling event. There were also significant differences for soil B (at the 1 and 3 mo sampling times) and for soil D (mo 1) (p<0.05). For the four mineral soils, alum-amended slurry reduced the average WEP of soil compared to the study control (average of 4 sampling events) by between 52 and 73%, lime by between 50 and 83%, PAC by between 21 and 64%, and FeCl3 by between 0 and 38%. These reductions in WEP were not consistently statistically significant. After 1 mo of incubation, the WEP of alum-amended slurry was significantly different to the slurrycontrol for soil B (89%), soil C (98%) and soil D (94%). Lime addition was also effective at reducing WEP compared to the slurry-control and there were significant reductions 132 after 1 mo for soils B (94%), C (98%) and D (97%) and after 3 mo for soils C (88%) and D (78%). Poly-aluminium chloride was less effective than alum or lime at reducing the WEP compared to the slurry-control with the only significant reductions occurring for soils C (81%) and D (54%) at the 1 mo sampling event. Ferric chloride was less effective than other amendments and much more variable: in soil C, WEP was significantly lower for soil which was mixed with FeCl3 treated slurry than the slurry-control after 1 mo (p<0.05). After 3 mo, soils A and D were significantly different to the slurry-control (p<0.05). There were no significant differences between WEP of the slurry-control and the soil amended with chemically amended slurry at the 6 and 9 mo sampling event. 7.4.2. Soil test phosphorus There was a significant interaction between soil type, month and treatment for the STP of the soil (p<0.001). The STP of incubated soil samples at each sampling time are shown in Figure 7.4. The STP of the soil only was observed to be much more stable than the WEP, and did not vary significantly during the course of the experiment. This was consistent with the results of Kalbasi and Karthikeyan (2004). The STP of soils which received dairy cattle slurry also remained relatively stable throughout the course of the experiment and although there were observed differences in STP between the control and soil-only treatments, these differences were not all statistically significant (p<0.05). For the four mineral soils, during the first month, alum reduced average STP of soil amended with alum-treated slurry compared to the slurry-control by between 13 to 58%, lime by between 0 and 62%, and PAC by between 13 and 46%. Ferric chloride increased STP by up to 30% at 1 mo; this was in agreement with the findings of Kalbasi and Karthikeyan (2004). The STP of the soil amended with alum, lime, PAC and FeCl3 was greater than the STP for each un-amended soil during the study. Chemical amendments did not have a significant effect on STP of the peat soil. These results indicated that there was no negative effect on plant available P with the use of a chemical amendment, with the exception of soil receiving FeCl3 amended slurry, the STP of which was significantly different to the slurry-control for soil A (mo 9) and soil B (mo 6 and 9). 133 Tunney et al. (2000) found a strong association between STP (measured using Morgan‘s extracting solution) and DRP concentrations in overland flow in Irish grassland soils. This relationship can vary between different hydrological conditions (Kurz et al, 2005) and soil types (Daly et al., 2001). Daly et al (2001) examined 11 soils chosen to best represent important agricultural grassland soils in Ireland varying in parent material, drainage, soil type and soil chemical properties. Daly et al (2001) found that, although STP was an important factor controlling P desorption, soil type also affected levels of sorption and desorption. Regan et al. (2010) found a similar relationship for tillage soils. 7.4.3. Soil pH There was a significant interaction between soil type, month and treatment for pH of soil (p<0.001). The pH of incubated soil samples at each sampling time are shown in Figure 7.5. The pH of the soil-only treatments did not significantly change as a result of the incubation experiment. Addition of dairy cattle slurry did not significantly alter soil pH for any of the soils examined. With the exception of FeCl3 (soil A, mo 9) (p<0.05), none of the amendments examined appeared to significantly affect soil pH. 7.5. Discussion 7.5.1. WEP The results of this study show that although there was an interaction with soil type, treatment and incubation duration, the WEP of soils mixed with chemically amended slurry was generally lower than the un-amended slurry-control. There were some instances where the WEP of soil which was incubated with FeCl3 amended slurry was greater than the control. Although these increases were not statistically significant, this may indicate that FeCl3 is not as stable as other amendments examined. These results indicate that chemical amendment may have beneficial impacts on the mitigation of longterm losses of P to surface runoff. 134 Soil Slurry Alum Lime 0 1 3 PAC FeCl 6 9 25 20 30 25 20 Soil A 35 15 15 10 5 10 0 20 5 0 Soil B 15 10 5 0 Soil C 10 5 Soil D 0 15 10 5 0 120 100 Soil E 80 60 40 20 0 Time (months) Figure 7.3 Water extractable phosphorus (WEP) of incubated soil samples at each sampling time (n=3) 135 Soil A 35 30 25 20 15 10 5 0 Soil B Soil 35 30 25 20 15 10 5 0 35 30 25 20 15 10 5 0 Slurry Alum Lime PAC FeCl Soil C 20 15 10 5 0 Soil D 20 15 10 5 0 Soil E 60 40 20 0 0 1 3 6 9 Time (months) Figure 7.4 Soil test P of incubated soil samples at each sampling time (n=3) 136 Soil Slurry Alum Lime PAC FeCl 8 6 30 25 20 Soil A 35 4 2 15 0 8 10 5 0 Soil B 6 4 2 0 8 Soil C 6 4 2 0 8 6 Soil D 4 2 0 8 Soil E 6 4 2 0 0 1 3 6 9 Time (months) Figure 7.5 pH of incubated soil samples at each sampling time (n=3) 137 In a similar study, Kalbasi and Karthikeyan (2004) found that application of alum and FeCl3 decreased P solubility in silt loam soil, while lime amendments increased WEP. This study found that Al-compounds (alum and PAC) reduced WEP in mineral soils. However, FeCl3 was as effective as the Al compounds, and lime addition resulted in the greatest reduction in WEP. In this study, lime was applied at a higher rate (16:1 compared to 10:1 (Ca:TP) in the Kalbasi and Karthikeyan (2004) study) and this may explain the difference in effectiveness. Anderson et al. (1995) amended soils - with a history of receiving dairy manure - with calcium carbonate (with the slurry pH adjusted to 7.5), gypsum (0 to 100 g kg-1 soil), ferrous sulphate (0 to 1 g kg-1 as Fe) and alum (0 to 1 g kg-1 as Al) in an incubation experiment. Calcium carbonate effectiveness was limited to soils with pH < 7.0 and gypsum was effective over a broad range of manure loading, pH and redox conditions. Although Al and Fe amendments to soil increased P retention by 400% relative to an un-amended control, Anderson et al. (1995) acknowledged elevated costs associated with amendments and the potential for biological toxicity. Runoff studies have been used to examine the addition of amendments to high STP soils to reduce P losses (McFarland et al, 2003; Novak and Watts, 2005; Brauer et al., 2005). Brauer et al. (2005) incorporated alum (127 kg Al ha-1) and gypsum at two rates (349 and 1163 kg Ca ha-1) into the upper 10 cm of a high STP soil on an annual basis for three years. Only the high gypsum treatment was observed to reduce WEP and STP values significantly during the study. A limited number of runoff studies have been carried out with chemical amendment of dairy cattle slurry (Elliot et al, 2005; Torbert et al, 2005) and swine slurry (Smith et al, 2001b), but little work has focused on the long-term effects of chemical amendments to slurry on the nutrient content of soil. Although this study gives a good indication of the stability of these amendments in the soil used in this study, it did not examine the effect of chemical amendments on the rate of mineralisation of fixed P to soluble WEP following loss of soluble P in runoff, or in drainage water. 138 7.5.2. Soil test phosphorus This study shows that one application of chemically amended slurry does not reduce plant availability of P in the soils examined in this study. In fact, in the case of FeCl3, STP was significantly increased for certain soils at the end of the study. This indicates that chemical amendment of dairy cattle may be a short-term management practice to control P surplus on a farm, but does not pose a risk to plant availability of P. In addition, it validates the work of Kalbasi and Karthikeyan (2004) for a range of soils found in Ireland using commercially available amendments. The amendments were buffered by organics in the peat soil examined in this study. In a high OM soil with a pH of 5.5, there is no free Al available, and any metals in the amendments are immediately buffered by organics, which reduces their effectiveness in reducing P solubility. There is a need to examine the effect of repeated applications of slurry amended with chemical amendments on STP and other soil properties. 7.5.3. Soil pH The pH of the mineral soils receiving FeCl3-amended dairy cattle slurry was consistently higher than the slurry-control (Figure 7.5), background and all other treatments. The Clin the FeCl3 treatment may have replaced OH- ions on the variable charge exchange sites in these soils, resulting in an increase in pH. This mechanism has been shown on HCltreated mineral soils with low starting pH and free iron oxides (Wang and Yu, 1998). An elevated soil pH was not measured in soil E. This was likely due to the high buffering capacity and lack of free iron sites in this organic soil. The national average soil pH is 5.5 for grasslands (Fay et al., 2007), which is below the recommended pH for optimum production of grass (6.3 for mineral soils and 5.5 for peat soils; Coulter and Lalor, 2008). Therefore, the soils examined in this study are representative of the pH range found in Ireland. The pH of a soil has a significant influence on nutrient availability (Tunney et al., 2010), and changes in pH can alter community composition and activity of microbes in soil (Sylvia et al., 2005). In addition, 139 if the amendments adversely affect the microbes, the microbes could potentially change the pH by their activity. Therefore, pH was examined as a means of determining if the amendments had the potential to have a significant effect on soil microbiology. 7.6. Conclusions This study found that although there were variations in the reductions in WEP of soil amended with dairy cattle slurry across soil types, the WEP of soil receiving chemically treated dairy cattle slurry was consistently, although not significantly, lower than the slurry-control. Soil test phosphorus and soil pH were not significantly affected by application of amended slurry, with the exception of FeCl3 amended slurry in some instances. Therefore, chemical amendment of dairy cattle slurry as a short-term management practice to control P loss does not pose a risk to plant availability of soil. There is a need to examine long-term effects of repeated applications of chemically amended dairy cattle slurry to develop an understanding of how amendments affect soil P release processes over time. 7.7. Summary This study indicates that the use of chemical amendment as a once-off management practice reduced WEP in soil compared to soil amended with slurry, but did not result in immobilisation of STP or have any significant effect on soil physical and chemical properties. Therefore, chemical amendment of dairy cattle slurry as a short-term management practice to control P loss does not pose an immediate risk to plant availability of soil. 140 Chapter 8 8.1. Conclusions and Recommendations Overview The objective of this study was to identify possible mitigation methods to prevent P loss to the environment during the land application of dairy cattle slurry. To address this, experiments were designed and conducted to evaluate the effectiveness, feasibility and pollution swapping potential of chemically amended dairy cattle slurry. The main conclusions of the study are now presented. 8.2. Conclusions 1. Experiments conducted at laboratory micro- and meso-scale, and micro plot-scale showed that chemical amendment was very successful in reducing incidental losses of DRP, TP, PP, TDP, DUP and SS from land-applied slurry. The results of the study demonstrate that PAC was the most effective amendment for decreasing DRP losses in runoff following slurry application, while alum was the most effective for TP and PP reduction. Incidental loss of metals (Al, Ca and Fe) from chemically amended dairy cattle slurry was below the MAC for receiving waters. 2. Although these treatments are expensive, they may be feasible if used strategically to mitigate P loss from dairy slurry in critical source areas within a farm. 3. The results of this study show that even with chemical amendment, P concentration in runoff was above the MAC. Therefore, amendments may not be 141 the best option for minimising incidental P losses, as timing of applications may be just as effective at controlling incidental P losses and may be much more cost effective. 4. This study showed that P mitigating amendments can result in pollution swapping. The amendments selected for recommendation for further study are, from best to worst, PAC, alum and lime (Table 8.1). In addition, at the current cost of treatment, the increase in fertiliser value of the slurry due to some treatments is not sufficient to offset the cost of treatment. In this study, there was no significant effect of any amendment, with the exception of charcoal, of slurry on GWP caused by the land application dairy cattle slurry. 5. Although there were variations in the reductions in WEP of soil amended with dairy cattle slurry across soil types, the WEP of soil receiving chemically treated dairy cattle slurry was consistently, although not significantly, lower than the slurry-control. Soil test phosphorus and soil pH were not significantly affected by the application of amended slurry, with the exception of FeCl3-amended slurry in some instances. Therefore, chemical amendment of dairy cattle slurry as a shortterm management practice to control P loss does not pose a risk to plant availability of soil. 142 Table 8.1 Summary of feasibility of amendments (adapted from Chapter 3). Marks for feasibility, pollution swapping, incubation study and plot study are from 1 to 5. 1 = best; 5 = worst. Chemical Agitator score P Pollution swapping Incubatio n study Plot Combined feasibility score Notes Alum 1 4 1 1 8 Risk of effervescence Risk of release of H2S due to anaerobic conditions and reduced pH Cheap and used widely in water treatment Reduced ammonia emissions AlCl3 (PAC) 2 1 3 2 7 No risk of effervescence (Smith et al., 2004) AlCl3 increased handling difficulty Expensive Reduced ammonia emissions FeCl2 (FeCl3) 3 3 4 4 14 Potential for Fe bonds to break down in anaerobic conditions Increased release of N2O Reduced ammonia emissions Not examined in plot study Ca(OH)2 4 2 2 3 11 Increased NH3 loss Strong odour Hazardous substance Not effective in plot study 8.3. Recommendations for future work 1. This work indicates that if amendments are to be implemented, extensive catchment-scale experiments, carried out over a number of years, are necessary to examine how amendments affect N leaching, plant availability of P, soil microbiology and structure, metal build-up in the soil, long-term release of P to runoff, gaseous emissions and pollution swapping. Such work should use land spreading equipment at farm-scale. 2. These results suggest that chemical amendment of dairy cattle slurry with PAC could be used to control P solubility and thus reduce incidental P losses from soils 143 receiving dairy cattle slurry without adversely affecting metal and N losses. Future work must examine the long-term stability of metal-to-P bonds formed as a result of chemical amendment of dairy cattle slurry following land application. There is a need to examine the use of chemical amendments to slurry under a wide range of conditions. 3. Results show that a once-off application of any of the chemical amendments examined will not result in a significant change in chemical and chemical properties, an increase in GHG emissions, a release of metals to runoff, or significant pollution swapping. It is, however, critical that the long-term effect of repeated applications of amendments on STP, soil pH, soil WEP, soil microbiology and macro-biology be examined. 4. The results of the gas experiment indicated that if a biochar could be engineered to sequester P as effectively as alum and PAC, it would be the ideal amendment, as charcoal has the potential to dramatically reduce GHG emissions. 8.4. Context Ireland has committed to meeting the requirements of the European Union Water Framework Directive (EU WFD; 2000/60/EC, OJEC, 2000) to achieve at least ‗good status‘ of all surface and groundwater by 2015. It is expected that the current programmes of measures (POM) will not reduce P losses sufficiently within this timeframe and that that substantial measures will be required to fulfil these obligations. While current practices are effective, there will be a time-lag before current changes in farming practices will result in an observable reduction in nutrient losses and reduction in risk to water quality. This study showed that amendments are effective and that there is no major risk of pollution swapping associated with alum and PAC. This is a significant finding as there is now potential to use amendments strategically, in combination with existing programme of measures (POM), to mitigate P losses. The next step will be to examine the use of chemical amendments at catchment-scale. 144 In future, farm nutrient management in Ireland must focus on examining all farms within a catchment and identifying areas which pose the greatest risk. 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Impact of chemical amendment of dairy cattle slurry on phosphorus, suspended sediment and metal loss to runoff from a grassland soil. Science of the Total Environment 409(23):5111-8. MANUCRIPTS IN PREPARATION Brennan RB, Fenton O, Healy MG, Lanigan G. Effect of chemical amendment of dairy cattle slurry on greenhouse gas and ammonia emissions (Submitted: Biological Engineering) Brennan RB, Fenton O, Grant J, Healy MG. Rainfall simulation study investigating the effect of chemical amendment of dairy cattle slurry on runoff characteristics and nutrient loss from grassland plots (Target journal: Science of the Total Environment). Brennan RB, Fenton O, Grant J, Healy MG. The long term impact of adding chemically amended dairy slurry to WEP, soil test phosphorus and pH in five grassland soils (Submitted: Journal of Environmental Quality). INTERNATIONAL CONFERENCE PAPERS Brennan RB, Fenton O, Healy MG. 2010. Chemical amendment of dairy cattle slurry for control of phosphorus in runoff from grasslands. A05 symposium on emerging 172 technologies to remove phosphorus. ASA-CSA-SSSA International Meetings, Long Beach, CA. 31 October - 4 November, 2010 (Oral presentation). Brennan RB, Fenton O, Healy MG. 2010. Evaluation of chemical amendments to control soluble phosphorus losses from dairy cattle slurry. (Eds. Turtola E, Ekholm P, Chardon W). In: MTT Science 10. Novel methods for reducing agricultural nutrient loading and eutrophication: Meeting of COST 869, 14-16 June, Jokioinen, Finland. p. 18 (Oral presentation). NATIONAL CONFERENCE PAPERS Brennan RB, Healy MG, Lanigan G, Fenton O. 2011. Chemical amendment of dairy cattle slurry for control of P in runoff from grasslands. Walsh Fellowship Seminars. 12 July, RDS, Co Dublin (Poster presentation). Brennan RB, Fenton O, Grant J, Healy MG. 2011. Mitigating incidental DRP losses from land application of dairy cattle slurry using chemical amendments. Agricultural Research Forum Conference. 14-15 March, Tullamore, Co. Offaly (Oral presentation). Brennan RB, Fenton O, Rodgers M, Healy MG. 2010. Chemical amendment of dairy cattle slurry for control of phosphorus in runoff from grasslands. SEGH 2010. 27 June - 2 July, 2010. National University of Ireland, Galway (Oral presentation). Brennan RB, Fenton O, Rodgers M, Healy MG. 2010. The addition of chemical amendments to dairy cattle slurry for the control of phosphorus in runoff from grasslands. BSAS/WPSA/Agricultural Research Forum Conference. Queen's University, Belfast. 1214 April, 2010 (Oral presentation). Brennan RB, Fenton O, Rodgers M, Healy MG. 2010. Chemical amendment of dairy cattle slurry to reduce P loss from grasslands. 19th World Congress of Soil Science. Brisbane, Australia, 1-6 August, 2010 (Poster presentation). 173 Appendix B Results of agitator test 174 Notation used in Appendix: DRP, dissolved reactive phosphorus Soil only – grassed soil sample Slurry – slurry control High, low and medium are rates as described in chapter 3 Alum, aluminium sulphate Wtr dry, sieved and dried Al-WTR Wtr wet, sludge Al-WTR Vw; represents volume of sample removed for analysis Vc, cumulative volume of sample removed during the experiment P is the concentration of P in overlying water Padj is the P concentration adjusted to take account of the change in volume of the overlying water during the experiment AlCl3, aluminium chloride FeCl2 ferric chloride FGD, flue gas desulphurisation by-product Table B.1 Results of preliminary batch study WTR FeCl2 FeSO4 MgCl2 Ca(OH)2 Amendment g/kg slurry pH DRP (mg/L) % reduction soluble P 0 7.3 23.9 20 7.5 17.1 28.5 50 7.6 13.29 44.4 100 7.7 11.6 51.5 150 7.84 5.6 76.6 300 7.95 0.5 97.9 0 7.4 24.4 1.6 7.2 5.6 77 5.5 6.84 0.33 98.6 10 6.6 0.1 99.6 20 6.2 0.05 99.8 0 7.38 20.4 1 7.23 18 11.8 Effective Effective Effective 5 6.98 11.6 43.1 10 6.8 0.7 96.6 20 6.56 0.13 99.4 0 7.38 14.943 1 7.4 2.612 82.5 5 7.33 2.171 85.5 10 7.24 3.081 79.4 20 6.96 3.305 77.9 50 6.28 7.673 48.7 0 7.5 31.707 1 8.2 12.221 61.5 5 10.1 10.499 66.9 10 12.5 3.156 90 20 12.6 1.057 96.7 50 12.7 0.707 97.8 175 Comment Not effective Effective CaO Al2(SO4)3 Fly ash Al2(SO4)3 Bottom ash Ferriox Septiox 0 7.4 22.681 Effective 1 7.66 16.323 28 5 7.93 12.207 46.2 10 8.12 9.926 56.2 20 8.42 2.481 89.1 50 12.63 0.684 97 0 7.48 20.941 1 6.64 17.457 16.6 5 4.37 5.128 75.5 10 3.89 5.13 75.5 20 3.55 2.971 85.8 50 2.97 0.939 95.5 0 7.3 18.412 10 7.43 16.953 7.9 20 7.49 13.387 27.3 50 7.56 15.182 17.5 100 7.62 9.331 49.3 150 7.72 5.385 70.8 300 7.76 2.926 84.1 400 7.92 1.38 92.5 0 7.31 24.512 0.3 7.02 19.115 22 0.5 6.89 11.564 52.8 1 6.63 3.933 84 1.5 6.21 1.357 94.5 2 5.73 0.375 98.5 0 7.33 14.263 10 7.4 14.067 1.4 20 7.44 16.088 -12.8 Effective Effective Effective Not effective 50 7.52 14.185 0.5 100 7.63 15.203 -6.6 150 7.74 14.626 -2.5 300 7.79 13.654 4.3 400 7.92 13.325 6.6 0 7.43 1 7.41 20.921 9.8 5 7.32 18.866 37.6 10 7.17 13.057 82.2 20 6.69 3.729 98 50 5.41 0.415 99.5 0 7.34 1 7.39 22.764 18.7 5 7.4 18.516 16.8 Effective Effective 176 FGD Charcoal Polyaluminium chloride 10 7.47 18.949 22.5 20 7.48 17.643 27.8 50 7.33 16.432 57.6 0 7.13 10 7.21 22.51 15.9 20 7.27 18.922 19.8 50 7.31 18.05 38.5 100 7.34 13.833 56.2 150 7.37 9.856 71.4 300 7.39 6.436 90.2 400 7.5 2.203 96.1 100 7.32 18.57 8 0 7.37 20.185 0 Effective 2 7.34 16 20.7 10 7.45 18.7 7.4 50 7.5 26 -28.8 0 7.18 20.921 0.3 7.22 18.866 10 0.5 7.3 13.057 38 1 7.36 3.729 82 1.5 3.43 0.415 98 2 7.48 0.103 100 Not effective Effective Note: The rates used in this experiment were based on values found in the literature. The most effective amendments were selected and examined in the agitator test. There are some exceptions to this rule: Calcium oxide (CaO) was not chosen as it is hazardous. Ferric sulphate (FeSO4) was not examined as it resulted in very strong smell. In addition commercial products Ferriox and Septiox were not examined further as they were expensive for this purpose. 177 Table B.2 Langmuir model applied to amendments which were effective in preliminary experiment and selected for use in agitator test (Chapter 3). 0.5 1.2 1 0.4 0.8 0.3 0.6 0.2 0.4 a=1 b = 1 mg P/ g Alum 0.2 0 0 0 5 10 0 15 6 6 5 5 4 4 3 2 4 6 3 a =0.35, b = 9.15 mg P /g Ca(OH)2 2 2 1 a =0.7, b = 11.2 mg P /g FeCl2 1 0 0 0 5 10 0 2 4 6 0.2 0.12 0.1 0.15 0.08 Cs Langmuir model (mg L-1) a =1, b = 0.52 mg P /g PAC 0.1 0.1 0.06 0.04 0 0 5 10 a =0.2, b = 0.21 mg P /g FGD 0.05 a =0.13, b = 0.45 mg P /g flyash 0.02 0 0 15 0.3 0.25 0.2 0.15 0.1 a =0.1, b = 0.31 mg P /g WTR 0.05 0 0 5 10 15 20 Solution equilibrium concentration (mg L-1) 178 5 10 15 Table B.3 Relationship between percentage reductions in dissolved reactive phosphorus and % reduction in P in overlying water percentage reduction in water extractable phosphorus of slurry (Chapter 3). Alum (aluminum sulphate) Aluminum chloride Ferric chloride Lime AL WTR (dry sieved) Al WTR (sludge) Fly ash FGD % reduction in water extractable P in slurry 179 Table B.4 Results of agitator test Control soil only Volume of water added ml Soil only Slurry Time (h) ml Vw Vc P Padj Mass P ml ml μg/l μg/l mg/m2 0 2 2 0 0 0 24 0.25 2 4 203 0.2 12.8 205 0.5 4 8 240 0.2 15 334 1 4 12 277 0.3 17.2 301 2 4 16 282 0.3 17.4 367 4 4 20 347 0.3 21.2 401 8 4 24 363 0.3 22 448 12 4 28 382 0.4 23 479 24 4 32 379 0.4 22.6 460 0 0 0 0 0 0 0.25 4 4 3100 3.1 195.8 3700 0.5 4 8 4100 4 256.8 4200 1 4 12 5800 5.7 360.4 6400 2 4 16 7600 7.4 468.3 8800 4 4 20 9900 9.5 605 10600 8 4 24 10700 10.2 648.5 13100 12 4 28 10900 10.3 655.1 11000 24 4 32 10900 10.2 649.5 11000 36 4 36 10400 9.7 614.4 10200 36 low alum Sample 1 500 0 10900 13100 0 0 0 0 0 0.25 4 4 324 0.3 20.5 487 0.5 4 8 563 0.6 35.3 785 1 4 12 709 0.7 44.1 1162 2 4 16 454 0.4 28 856 4 4 20 973 0.9 59.5 2025 8 4 24 1042 1 63.2 2325 12 4 28 1086 1 65.3 2470 4 32 1163 1.1 69.3 2669 24 32 high alum 0 69.3 0 0 0 0 0 4 549 0.5 34.7 500 0.25 4 0.5 4 8 770 0.8 48.2 795 1 4 12 1195 1.2 74.3 1295 2 4 16 1512 1.5 93.2 1812 4 4 20 1781 1.7 108.8 1981 180 8 4 24 1943 1.8 117.8 2143 12 4 28 2222 2.1 133.5 2348 4 32 2721 2.5 162.1 2721 24 32 med alum 0 162.1 0 0 0 0 0 0.25 4 4 199.054 0.2 12.6 269.079 0.5 4 8 236.702 0.2 14.8 335.064 1 4 12 325.291 0.3 20.2 429.671 2 4 16 497.673 0.5 30.7 647.708 4 4 20 592.011 0.6 36.2 760.275 8 4 24 609.977 0.6 37 835 12 4 28 831.11 0.8 49.9 1005.124 24 4 32 901 0.8 53.7 984 32 low lime 0 53.7 0 0 0 0 0 4 2859 2.8 180.6 2329 0.25 4 0.5 4 8 4293 4.2 268.9 3112 1 4 12 5730 5.6 356 4454 2 4 16 7050 6.8 434.5 6194 4 4 20 8485 8.1 518.6 8118 8 4 24 9986 9.5 605.2 9888 12 4 28 9513 9 571.7 8604 24 4 32 12158 11.4 724.5 9960 32 med lime 0 724.5 0 0 0 0 0 0.25 4 4 1438 1.4 90.8 1031 0.5 4 8 1698 1.7 106.4 1500 1 4 12 1739 1.7 108.1 1987 2 4 16 1888 1.8 116.3 2512 4 4 20 2184 2.1 133.5 2360 8 4 24 2268 2.2 137.5 2419 12 4 28 2912 2.7 175 2059 24 4 32 3066 2.9 182.7 2990 32 high lime 0 182.7 0 0 0 0 0 0.25 4 4 304 0.3 19.2 514 0.5 4 8 365 0.4 22.9 670 1 4 12 513 0.5 31.9 1154 2 4 16 746 0.7 46 544 181 4 4 20 674 0.6 41.2 1317 8 4 24 796 0.8 48.2 1443 12 4 28 2245 2.1 134.9 2289 24 4 32 1359 1.3 81 2163 32 low dry wtr 0 134.9 0 0 0 0 0 0.25 4 4 2016 2 127.3 2450 0.5 4 8 2282 2.2 143 2642 1 4 12 2670 2.6 165.9 2771 2 4 16 3015 2.9 185.8 2919 4 4 20 6672 6.4 407.8 5446 8 4 24 6975 6.6 422.7 5570 12 4 28 6920 6.5 415.9 5603 4 32 8353 7.8 497.7 8058 24 32 med dry wtr 0 497.7 0 0 0 0 0 0.25 4 4 626 0.6 39.5 433 0.5 4 8 869 0.9 54.4 456 1 4 12 819 0.8 50.9 673 2 4 16 1701 1.6 104.8 877 4 4 20 1887 1.8 115.3 1024 8 4 24 1885 1.8 114.2 1066 12 4 28 1795 1.7 107.9 1074 24 4 32 4814 4.5 286.9 1760 32 high dry wtr 0 286.9 0 0 0 0 0 4 393 0.4 24.8 224 0.25 4 0.5 4 8 574 0.6 36 333 1 4 12 419 0.4 26 355 2 4 16 411 0.4 25.3 336 4 4 20 361 0.3 22.1 287 8 4 24 281 0.3 17 242 12 4 28 295 0.3 17.7 236 24 4 32 2221 2.1 132.3 3759 32 low wet wtr 0 132.3 0 0 0 0 0 0.25 4 4 4345 4.3 274.4 6256 0.5 4 8 4305 4.2 269.7 6258 1 4 12 5720 5.6 355.4 8423 182 2 4 16 7610 7.4 469 10748 4 4 20 9656 9.3 590.1 11080 8 4 24 11359 10.8 688.4 13012 12 4 28 11722 11.1 704.5 13265 24 4 32 13090 12.3 780 13553 32 med wet wtr 0 780 0 0 0 0 0 0.25 4 4 2655 2.6 167.7 3482 0.5 4 8 1268 1.2 79.4 1584 1 4 12 2361 2.3 146.7 2749 2 4 16 2739 2.7 168.8 1331 4 4 20 2709 2.6 165.6 1924 8 4 24 2313 2.2 140.2 2657 12 4 28 1973 1.9 118.6 2145 4 32 2148 2 128 2577 24 32 high wet wtr 0 168.8 0 0 0 0 0 0.25 4 4 3591 3.6 226.8 3797 0.5 4 8 2604 2.6 163.1 2385 1 4 12 3354 3.3 208.4 3046 2 4 16 3857 3.7 237.7 3409 4 4 20 4027 3.9 246.1 3471 8 4 24 3536 3.4 214.3 3130 12 4 28 3151 3 189.4 2865 24 4 32 2233 2.1 133.1 2063 32 Flyash high 0 246.1 0 0 0 0 0 4 1029 1 65 1411 0.25 4 0.5 4 8 2461 2.4 154.2 780 1 4 12 2102 2.1 130.6 2191 2 4 16 3045 2.9 187.6 3094 4 4 20 2918 2.8 178.3 3108 8 4 24 1825 1.7 110.6 2094 12 4 28 1639 1.5 98.5 1639 24 4 32 1426 1.3 85 1797 32 Flyash medium 0 187.6 0 0 0 0 0 0.25 4 4 352 0.3 22.2 1391 0.5 4 8 459 0.5 28.8 2277 1 4 12 676 0.7 42 2001 183 2 4 16 898 0.9 55.3 2198 4 4 20 1143 1.1 69.9 2283 8 4 24 1391 1.3 84.3 2563 12 4 28 1399 1.3 84.1 2525 24 4 32 1661 1.6 99 3171 32 Flyash low 0 99 0 0 0 0 0 0.25 4 4 1965 1.9 124.1 2243 0.5 4 8 2790 2.7 174.8 3016 1 4 12 3240 3.2 201.3 3780 2 4 16 4181 4 257.7 4083 4 4 20 4732 4.5 289.2 4343 8 4 24 5122 4.9 310.4 4641 12 4 28 6888 6.5 413.9 5725 24 4 32 7967 7.5 474.7 6640 32 FeCl low 0 474.7 0 0 0 0 0 0.25 4 4 485 0.5 30.7 0 0.5 4 8 610 0.6 38.3 819 1 4 12 759 0.7 47.2 934 2 4 16 1002 1 61.8 1109 4 4 20 1331 1.3 81.4 1289 8 4 24 1750 1.7 106.1 1598 12 4 28 1945 1.8 116.9 1634 4 32 2398 2.2 142.9 1556 24 32 FeCl2 high 0 142.9 0 0 0 0 0 0.25 4 4 428 0.4 27.1 73 0.5 4 8 442 0.4 27.7 96 1 4 12 430 0.4 26.7 107 2 4 16 519 0.5 32 103 4 4 20 367 0.4 22.5 97 8 4 24 123 0.1 7.5 4.152 12 4 28 57 0.1 3.5 14 24 4 32 2 0 1.4 18 32 FeCl2 med 0 32 0 0 0 0 0 0.25 4 4 418 0.4 26.5 601 0.5 4 8 552 0.5 34.6 732 184 1 4 12 797 0.8 49.5 943 2 4 16 1056 1 65.1 1086 4 4 20 1519 1.5 92.8 1090 8 4 24 1680 1.6 101.8 968 12 4 28 1742 1.6 104.7 939 24 4 32 1889 1.8 112.6 821 32 AlCl3 low 0 112.6 0 0 0 0 0 4 645 0.6 40.8 192 0.25 4 0.5 4 8 914 0.9 57.2 360 1 4 12 1124 1.1 69.8 448 2 4 16 1536 1.5 94.7 700 4 4 20 1730 1.7 105.7 860 8 4 24 1809 1.7 109.7 1006 12 4 28 1851 1.7 111.2 998 24 4 32 2454 2.3 146.2 949 32 AlCl3 med 0 146.2 0 0 0 0 0 0.25 4 4 367 0.4 23.1 365 0.5 4 8 553 0.5 34.7 415 1 4 12 735 0.7 45.7 423 2 4 16 932 0.9 57.4 519 4 4 20 1063 1 65 606 8 4 24 1055 1 63.9 713 12 4 28 1085 1 65.2 745 24 4 32 1037 1 61.8 811 32 AlCl3 high 0 65.2 0 0 0 0 0 0.25 4 4 105 0.1 6.7 96 0.5 4 8 126 0.1 7.9 122 1 4 12 142 0.1 8.8 148 2 4 16 123 0.1 7.6 182 4 4 20 100 0.1 6.1 189 8 4 24 13 0 0.8 83 12 4 28 16 0 0.9 30 4 32 15 0 0.9 77 24 32 FGD high 0 0.25 4 8.8 0 0 0 0 0 4 269 0.3 17 185 185 0.5 4 8 348 0.3 21.8 281 1 4 12 395 0.4 24.5 318 2 4 16 482 0.5 29.7 467 4 4 20 624 0.6 38.1 532 8 4 24 809 0.8 49 679 12 4 28 888 0.8 53.4 722 4 32 880 0.8 52.4 744 24 32 FGD med 0 53.4 0 0 0 0 0 0.25 4 4 354 0.4 22.4 287 0.5 4 8 465 0.5 29.1 432 1 4 12 602 0.6 37.4 506 2 4 16 755 0.7 46.5 744 4 4 20 942 0.9 57.6 976 8 4 24 1206 1.1 73.1 1450 12 4 28 1265 1.2 76 1378 24 4 32 1445 1.4 86.1 1459 32 FGD low 0 86.1 0 0 0 0 0 4 379 0.4 23.9 1269 0.25 4 0.5 4 8 420 0.4 26.3 1634 1 4 12 620 0.6 38.5 2018 2 4 16 850 0.8 52.4 2477 4 4 20 1282 1.2 78.4 3272 8 4 24 1662 1.6 100.7 3611 12 4 28 1938 1.8 116.5 4516 24 4 32 2359 2.2 140.6 4815 32 Sample 2 Soil only 140.6 Sample 3 500 ml Padj Mass P μg/l Mean of adjusted values 500 ml P Padj mg/m2 mg/l mg/l Mass P mg/m2 0.023904 1.5 0 0.20 13 66 0.07 4.17 0.33 20 79 0.08 4.95 0.29 19 110 0.11 6.83 0.36 23 131 0.13 0.38 25 162 0.43 27 171 Mass P mg/m2 dev t^(1/2) 0.88 0 6.17 5.03 0.25 10.98 8.08 0.5 14.99 6.46 1 8.07 14.72 7.37 2 0.16 9.9 17.91 7.66 4 0.16 10.36 18.96 8.6 8 0 186 Slurry 0.45 29 203 0.19 12.2 20.77 8.41 12 0.43 27 174 0.16 10.37 20.58 8.78 24 0 0 0 0 0 0 0 4 234 5200 5.16 328.39 252.61 68.31 0.25 4 263 6500 6.4 407.18 309.04 85.05 0.5 6 398 7700 7.52 478.43 412.16 60.35 1 9 543 9500 9.2 585.44 532.03 59.22 2 10 647 9500 9.12 580.6 611.15 34.03 4 12 794 11800 11.23 715.15 719.19 72.81 8 10 661 13000 12.27 781.26 699.13 71.19 12 10 655 10400 9.73 619.71 641.56 19.15 24 9 603 10500 9.74 620.32 612.45 9.02 36 13000 low alum 719.19 0.00 0 0 0 0 0 0 0.48 30 407 0.4 24.72 25.31 5.17 0.25 0.77 49 563 0.55 33.91 39.45 8.45 0.5 1.13 72 812 0.79 48.49 54.91 15.13 1 0.83 52 1147 1.11 67.91 49.55 20.16 2 1.94 124 1585 1.52 93.03 92.09 32.16 4 2.21 141 1258 1.2 73.2 92.42 42.29 8 2.33 148 1720 1.62 99.21 104.3 41.82 12 2.50 159 2340 2.18 133.77 120.7 46.28 24 133.77 120.7 159 high alum 0.00 0 0 0 0 0.49 22 496 0.49 31.32 0.78 35 877 0.86 1.25 56 1493 1.46 1.72 77 2011 1.86 83 1.99 2.16 2.47 0 0 29.34 6.55 0.25 54.94 45.93 10.35 0.5 92.77 74.25 18.52 1 1.95 123.93 98.05 23.81 2 2371 2.28 144.9 112.33 30.98 4 89 2429 2.31 147.21 117.97 29.13 8 96 2500 2.36 150.24 126.68 27.63 12 110 2524 2.36 150.4 140.9 27.25 24 150.4 140.9 110 med alum 0 0.00 0 0 0 0 0.26 17 169 0.17 10.68 0.32 15 217 0.21 0.41 19 277 0.62 28 385 0.72 33 0.79 0.95 0 0 0 13.41 3.24 0.25 13.6 14.37 0.67 0.5 0.27 17.23 18.71 1.49 1 0.37 23.71 27.44 3.51 2 502 0.48 30.71 33.14 2.79 4 35 675 0.64 40.91 37.77 2.83 8 42 710 0.67 42.68 44.97 4.32 12 187 0.92 41 733 0.69 42 low lime 46.14 0 0 0 2.31 147 3730 3.7 235.56 3.06 194 4761 4.68 4.30 276 5823 5.90 381 7233 7.70 496 9.41 6.67 24 0 0 0 187.73 44.67 0.25 298.25 254.04 53.23 0.5 5.68 361.81 331.53 47.53 1 7 445.73 420.63 34.18 2 8816 8.46 538.79 517.83 21.34 4 599 9139 8.7 553.88 586.12 28.08 8 8.12 517 10465 9.88 628.91 572.56 55.93 12 9.32 593 13972 13.08 832.56 716.84 119.72 24 832.56 716.84 0 0.00 0 0 0 0 0 1.02 65 2996 2.97 189.21 115.04 78.54 0.25 1.48 93 2901 2.85 181.73 127.35 74.56 0.5 1.94 123 2951 2.88 183.36 138.29 76.39 1 2.43 154 3080 2.98 189.8 153.65 82.48 2 2.27 144 3000 2.88 183.35 153.69 79.77 4 2.30 146 2777 2.64 168.3 150.79 76.5 8 1.94 123 2760 2.61 165.87 154.87 80.59 12 2.80 178 3522 3.3 209.87 190.24 96.15 24 209.87 190.24 0.00 0 0 0 0 0.51 32 330 0.33 20.84 0.66 42 407 0.4 25.5 1.13 72 1144 1.12 0.53 34 1148 1.26 80 1.37 87 2.16 2.02 0 0 0 24.17 7.23 0.25 30.11 10.36 0.5 71.08 58.22 22.82 1 1.11 70.75 50.08 18.95 2 789 0.76 48.22 56.63 20.96 4 806 0.77 48.85 61.52 22.47 8 138 2416 2.28 145.19 139.22 5.34 12 129 1448 1.36 86.28 98.72 26.26 24 145.19 139.22 138 low dry wtr 43.68 0 178 high lime 46.14 0.00 599 med lime 43.68 0.00 0 0 0 0 2.43 155 1837 1.82 116.01 2.60 166 2142 2.11 2.70 172 2572 2.51 2.83 180 5090 5.23 333 5.30 338 0 0 0 132.7 19.92 0.25 134.18 147.55 16.16 0.5 159.8 165.97 6.19 1 4.93 313.67 226.45 75.59 2 5378 5.16 328.68 356.43 44.51 4 5639 5.37 341.76 367.35 48 8 188 5.29 337 5528 5.22 332.22 361.6 47.05 12 7.54 480 8478 7.94 505.18 494.36 12.85 24 505.18 494.36 480 med dry wtr 0.00 0 0 0 0 0.43 27 479 0.48 30.25 0.45 29 650 0.64 0.66 42 895 0.87 0.85 54 1277 0.98 63 1.01 1.01 1.65 0 0 32.38 6.37 0.25 40.72 41.24 12.94 0.5 55.61 49.43 7.01 1 1.24 78.69 79.19 25.39 2 1401 1.34 85.62 87.84 26.44 4 65 1300 1.24 78.79 85.88 25.57 8 65 1253 1.18 75.3 82.57 22.56 12 105 1496 1.4 89.14 160.29 109.89 24 89.14 160.29 105 high dry wtr 0.00 0 0 0 0 0.22 14 3984 3.95 251.6 0.33 21 1964 1.93 123.03 0.35 22 3084 3.01 0.33 21 2307 2.23 0.28 18 1507 0.23 15 0 96.86 134.12 0.25 59.95 55.15 0.5 191.62 79.9 96.77 1 142.17 62.73 68.83 2 1.45 92.1 43.9 41.8 4 888 0.85 53.82 28.51 21.95 8 0.22 14 984 0.93 59.14 30.35 24.99 12 3.52 224 3302 3.09 196.76 184.36 47.06 24 251.6 184.36 0 0.00 0 0 0 0 0 0 6.21 395 1681 1.67 106.16 258.55 145.11 0.25 6.16 392 2577 2.54 161.43 274.38 115.37 0.5 8.22 523 3963 3.87 246.24 375 139.59 1 10.40 662 5813 5.63 358.22 496.51 153.92 2 10.64 677 8452 8.11 516.55 594.61 80.4 4 12.39 789 9595 9.13 581.52 686.18 103.56 8 12.52 797 9749 9.2 585.88 695.84 105.91 12 12.69 808 9216 8.63 549.16 712.25 141.91 24 585.88 712.25 808 med wet wtr 0 0 224 low wet wtr 0 0.00 0 0 0 0 3.45 220 3764 3.73 237.71 1.56 99 1878 1.85 2.68 171 3097 3.02 1.29 82 1634 1.85 118 2.53 161 0 0 0 208.42 36.4 0.25 117.64 98.77 19.11 0.5 192.43 169.98 22.88 1 1.58 100.69 117.17 45.67 2 1336 1.28 81.65 121.6 42.1 4 1602 1.53 97.09 132.77 32.61 8 189 2.02 129 2528 2.39 151.92 133.13 17.07 12 2.41 154 2673 2.5 159.28 146.94 16.66 24 237.71 208.42 220 high wet wtr 0.00 0 0 0 0 3.77 240 1541 1.53 97.32 2.35 149 2111 2.08 2.97 189 2828 2.76 3.30 210 3650 3.33 212 2.98 2.70 1.93 0 0 187.96 78.77 0.25 132.24 148.26 15.47 0.5 175.72 191.12 16.42 1 3.53 224.93 224.23 13.82 2 3895 3.74 238.04 232.1 17.75 4 190 3628 3.45 219.88 207.96 16.06 8 172 3223 3.04 193.69 185.08 11.38 12 123 2455 2.3 146.29 134.09 11.71 24 238.04 232.1 240 Flyash high 0.00 0 0 0 0 1.40 89 1994 1.98 125.93 0.77 49 1007 0.99 2.14 136 2020 2.99 191 3531 2.98 190 1.99 0 93.34 30.69 0.25 63.08 88.7 57.14 0.5 1.97 125.51 130.75 5.31 1 3.42 217.6 198.64 16.49 2 3036 2.91 185.55 184.61 5.86 4 127 2318 2.21 140.49 126 14.96 8 1.55 98 2254 2.13 135.46 110.82 21.34 12 1.68 107 2026 1.9 120.72 104.26 18.04 24 217.6 198.64 0.00 0 0 0 0 1.38 88 551 0.55 34.8 2.24 143 692 0.68 1.95 124 861 0.84 2.13 135 1101 2.19 140 2.44 2.38 2.97 0 0 0 48.29 34.83 0.25 43.35 71.58 61.97 0.5 53.5 73.28 44.59 1 1.07 67.85 86.21 43.1 2 1335 1.28 81.59 96.99 37.3 4 155 1623 1.55 98.36 112.67 37.61 8 152 1619 1.53 97.3 111.04 35.87 12 189 1965 1.84 117.09 135.01 47.59 24 117.09 135.01 189 Fly ash low 0 0 191 Fly ash medium 0 0.00 0 0 0 0 2.23 142 2204 2.19 139.19 2.97 189 2197 2.16 3.69 235 3113 3.95 252 3286 4.17 265 3860 0 0 0 134.98 9.51 0.25 137.63 167.11 26.5 0.5 3.04 193.42 209.87 22.01 1 3.18 202.5 237.26 30.25 2 3.71 235.91 263.51 26.7 4 190 4.42 281 4463 4.25 270.49 287.39 20.66 8 5.40 344 5248 4.95 315.39 357.8 50.7 12 6.22 396 6007 5.62 357.94 409.45 59.6 24 357.94 409.45 396 FeCl low 0.00 0 0 0 0 0.00 0 332 0.33 20.97 0.81 51 410 0.4 25.71 0.91 58 437 0.43 1.07 68 554 1.24 79 1.52 97 1.54 1.46 0 0 17.21 15.67 0.25 38.42 12.8 0.5 27.18 44.14 15.66 1 0.54 34.15 54.76 18.15 2 539 0.52 32.97 64.38 27.23 4 501 0.48 30.37 77.79 41.32 8 98 458 0.43 27.55 80.88 47.12 12 93 583 0.55 34.74 90.13 54.12 24 34.74 90.13 98 FeCl high 0.00 0 0 0 0 0.07 5 49 0.05 3.07 0.09 6 58 0.06 0.10 7 76 0.07 0.10 6 77 0.09 6 0.00 0.01 0.02 0 11.59 13.41 0.25 3.64 12.46 13.25 0.5 4.75 12.72 12.18 1 0.07 4.77 14.39 15.27 2 65 0.06 3.95 10.8 10.16 4 0 7 0.01 0.4 2.7 4.12 8 1 3 0 0.18 1.5 1.73 12 1 19 0.02 1.13 1.22 0.2 24 4.77 14.39 0.00 0 0 0 0 0.60 38 289 0.29 18.23 0.72 46 383 0.38 23.98 0.92 59 539 0.53 1.05 67 673 0.65 1.05 67 734 0.92 59 0.89 0.77 0 0 0 27.55 9.92 0.25 34.82 10.94 0.5 33.46 47.2 12.73 1 41.47 57.85 14.21 2 0.7 44.86 68.11 24.03 4 723 0.69 43.82 68.12 30.13 8 56 750 0.71 45.07 68.75 31.68 12 49 781 0.73 46.52 69.35 37.44 24 46.52 69.35 67 AlCl3 low 0 0 7 FeCl med 0 0 0.00 0 0 0 0 0 0 0.19 12 512 0.51 32.34 28.41 14.71 0.25 0.35 23 625 0.61 39.13 39.64 17.35 0.5 0.44 28 786 0.77 48.84 48.82 21 1 0.68 43 1019 0.99 62.8 66.87 26.01 2 191 0.83 53 1253 1.2 76.57 78.28 26.63 4 0.96 61 1404 1.34 85.08 85.23 24.35 8 0.94 60 1454 1.37 87.38 86.2 25.66 12 0.89 57 1503 1.41 89.53 97.43 45.36 24 89.53 97.43 61 AlCl3 med 0.00 0 0 0 0 0 0 0.36 23 302 0.3 19.04 21.75 2.34 0.25 0.41 26 455 0.45 28.52 29.73 4.46 0.5 0.41 26 622 0.61 38.62 36.87 9.81 1 0.50 32 820 0.79 50.55 46.64 13.18 2 0.58 37 1034 0.99 63.19 55.07 15.63 4 0.68 43 1080 1.03 65.46 57.54 12.43 8 0.70 45 999 0.94 60.01 56.67 10.62 12 0.76 48 857 0.8 51.07 53.72 7.12 24 65.46 57.54 48 AlCl3 high 0.00 0 0 0 0 0.10 0.12 6 94 0.09 5.94 8 120 0.12 7.52 0.14 9 145 0.14 0.18 11 150 0.18 12 0.08 5 0.03 0.07 0 6.23 0.38 0.25 7.68 0.19 0.5 9.01 9.01 0.19 1 0.15 9.24 9.36 1.81 2 145 0.14 8.86 8.85 2.73 4 50 0.05 3.03 2.95 2.14 8 2 25 0.02 1.5 1.41 0.44 12 5 40 0.04 2.38 2.61 1.85 24 9.24 9.36 0.00 0 0 0 0 0.18 12 527 0.52 33.25 0.28 18 591 0.58 0.31 20 683 0.67 0.45 29 810 0.51 33 0.65 0.68 0.70 0 0 0 20.64 11.24 0.25 37.02 25.47 10.22 0.5 42.43 28.91 11.95 1 0.78 49.92 36.13 11.95 2 929 0.89 56.76 42.47 12.69 4 41 901 0.86 54.62 48.27 6.77 8 43 1020 0.96 61.3 52.68 8.97 12 44 1315 1.23 78.36 58.38 17.77 24 78.36 58.38 44 FGD med 0 0 12 FGD high 0 0.00 0 0 0 0 0.28 18 431 0.43 27.22 0.43 27 436 0.43 0.49 31 481 0.47 192 0 0 0 22.57 4.55 0.25 27.31 27.83 1.13 0.5 29.89 32.91 3.97 1 0.72 46 643 0.62 39.62 44 3.8 2 0.94 60 846 0.81 51.7 56.31 4.12 4 1.38 88 998 0.95 60.48 73.82 13.71 8 1.30 83 1120 1.06 67.31 75.38 7.77 12 1.37 87 1160 1.09 69.12 80.72 10.05 24 69.12 80.72 88 FGD low 0.00 0 0 0 0 1.26 80 361 0.36 22.8 1.61 102 496 0.49 1.97 125 658 2.40 153 928 3.14 200 3.44 0 0 0 42.29 32.78 0.25 31.07 53.25 42.6 0.5 0.64 40.88 68.26 49.48 1 0.9 57.19 87.4 56.55 2 1416 1.36 86.54 121.62 67.98 4 219 2071 1.97 125.52 148.36 62.29 8 4.26 271 3084 2.91 185.34 191.07 77.62 12 4.51 287 3071 2.87 182.99 203.49 75.3 24 185.34 203.49 287 193 0 Appendix C Runoff box study results 194 Notation used in Appendix C Treatment: treatments as described in chapter 4 Event: This number corresponds to the number of the rainfall simulation event Volume runoff: total volume of runoff collected during 1 hr runoff event SS FWMC: flow-weighted mean concentration of suspended solids DRP FWMC: flow-weighted mean concentration of dissolved reactive phosphorus TP FWMC: flow-weighted mean concentration of total phosphorus PP FWMC: flow-weighted mean concentration of particulate phosphorus Cd: flow-weighted mean concentration of cadmium Cr: flow-weighted mean concentration of chromium Cu: flow-weighted mean concentration of copper K: flow-weighted mean concentration of potassium Ni: flow-weighted mean concentration of nickel Pb: flow-weighted mean concentration of lead Zn: flow-weighted mean concentration of zinc Al: flow-weighted mean concentration of aluminium Ca: flow-weighted mean concentration of calcium Fe: flow-weighted mean concentration of iron Time to runoff, time from start of rainfall simulator to start of event and thus start of 1 hr collection period WEP: Slurry WEP at time of application DM: slurry DM at time of application pH runoff water: pH of runoff collected RS rainfall simulation event as described in Chapter 4 Tank: source mains water in NUI Galway Table C.1. Runoff box study flow weighted mean concentrations Treatment Event Grass Grass Grass Grass Grass Grass Grass Grass Grass slurryonly slurryonly slurryonly slurryonly slurryonly slurryonly slurryonly slurryonly slurryonly alum alum alum 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 Volume runoff ml 4610.7 4764.36 4688.3 4697.4 4752.2 4770.2 5198 4495 5576 4647 4975.7 4849.3 3982 4685 4648 4476 4696 4784 4519 4516 4560 Intensity mm/hr 10 11 10 10 11 11 12 12 10 10 11 11 9 10 10 10 10 11 10 10 10 SSFWMC mg/l 296 93 82 235 139 202 192 138 84 4552 4573 1763 3217 3409 1999 2362 3673 1720 406 231 330 195 DRPFWMC μg/l 87.66 100.80 85.15 169.39 171.49 188.61 238.44 271.73 222.78 896.26 952.73 342.29 358.98 821.19 1114.64 477.02 459.10 478.21 66.34 104.55 61.13 PPFWMC μg/l 124.74 76.03 50.73 42.59 36.10 24.43 122.95 438.16 93.82 7847.17 9362.10 4183.47 7527.58 8242.42 3931.55 6622.45 7108.90 3291.73 397.81 218.33 204.44 TPFWMC mg/l 0.32 0.23 0.18 0.23 0.24 0.25 0.59 0.88 0.45 9.17 11.15 5.02 9.45 10.35 5.52 7.79 11.57 5.60 0.64 0.36 0.33 Cd µg/l 1.89 1.25 1.41 1.52 1.27 1.72 0.15 0.05 0.38 0.92 0.12 1.45 0.05 0.21 1.51 0.29 0.24 0.63 0.47 0.50 1.69 alum alum alum alum alum alum PAC PAC PAC PAC PAC PAC PAC PAC PAC lime lime lime lime lime lime lime lime lime ferrous ferrous ferrous ferrous ferrous ferrous ferrous ferrous ferrous 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 Treatment Event Grass Grass Grass Grass Grass Grass Grass Grass Grass slurryonly slurryonly slurryonly slurryonly slurryonly slurryonly slurryonly slurryonly slurryonly alum alum 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 4916 4871 4609 4226 4403 4565.8 4712 4766 4474 4181 4029 4213 4524 4559 4352 5399.6 4251 4689 5930 5119 5061.8 4343 4650 4769 4533 4679 4638 4226 4315 4278 4210 4243 4342 Cr µg/l 5.34 2.11 2.17 1.09 1.00 1.29 0.12 0.82 2.19 5.84 4.01 4.54 3.38 2.16 3.46 3.43 2.28 3.83 2.47 2.53 Cu µg/l 22.26 11.91 15.07 14.33 9.88 15.09 23.14 9.69 12.32 29.17 32.78 66.03 33.38 28.52 73.17 20.67 18.56 59.41 14.22 20.39 K mg/l 38.99 31.06 26.17 21.21 16.69 16.31 14.02 11.24 11.74 21.27 35.02 74.17 51.49 60.51 81.82 56.12 53.13 78.69 129.86 149.74 11 11 10 9 10 10 10 11 10 9 9 9 10 10 10 12 9 10 13 11 11 10 10 11 10 10 10 9 10 10 9 9 10 Ni µg/l 0 0 0.7857 0 0.4031 1.1919 2.0594 8.065 2.2605 4.5977 3.0928 38.751 6.416 1.3506 15.89 0.1083 1.1696 9.9897 1.3875 3.9019 357 249 293 536 520 392 772 478 450 683 638 497 465 316 416 753 582 462 641 652 496 572 462 410 1758 1406 1023 852 731 711 808 1275 913 Pb µg/l 6.4 11.0 5.8 4.2 2.0 13.9 1.2 7.2 8.4 3.5 1.7 3.0 3.0 4.4 17.4 0.1 4.3 10.3 6.5 12.3 196 176.48 185.55 200.02 52.15 86.92 90.55 83.49 50.13 73.06 138.13 97.66 166.55 67.99 68.17 55.16 277.47 283.89 114.31 264.65 195.07 84.67 216.34 183.95 174.58 152.26 246.03 254.56 171.94 149.38 190.67 236.03 275.97 291.02 Zn µg/l 407.9 460.8 718.9 279.2 419.6 752.5 419.2 413.8 520.4 258.9 349.2 216.4 333.1 332.3 345.3 446.7 440.1 263.3 666.8 1413.1 Al µg/l 176.3 67.5 79.4 83.5 81.5 51.2 54.3 56.8 45.3 63.4 52.0 116.2 59.3 59.1 210.9 59.7 81.9 112.9 65.6 65.6 555.08 136.40 247.20 385.32 293.28 123.70 1269.21 935.78 899.53 439.34 639.87 309.39 1110.15 896.58 621.26 936.10 620.63 205.23 838.61 1125.78 601.92 312.81 16.85 298.41 2971.16 2488.45 1910.10 1420.25 1002.18 1020.95 1898.58 1878.18 1268.48 Ca mg/l 91.3 83.2 87.8 85.4 80.5 84.2 83.9 81.3 80.8 106.3 110.7 103.3 117.4 110.5 102.6 114.7 107.5 97.3 141.8 150.3 0.84 0.36 0.51 0.58 0.54 0.39 1.59 1.13 1.08 1.12 1.44 0.69 1.35 1.16 0.80 1.77 1.53 0.70 1.78 1.88 1.08 1.03 0.67 0.94 3.31 3.25 2.69 1.97 1.56 1.45 2.70 2.67 1.94 Fe µg/l 128.7 74.6 67.5 61.2 70.6 65.5 73.1 53.0 44.8 128.0 190.6 103.6 194.0 227.7 137.1 127.2 116.9 131.1 110.8 148.3 1.33 1.02 0.85 0.96 0.04 0.88 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Time to runoff min pH tank water 10 7 11 10 7 11 10.45 8 9 17 9 26 20 12 20 18 10 23 21 13 8 8 8 8 8 7.9 8 8.1 8 8 7.6 7.8 8 8 4 8 8 8 8 8 alum alum alum alum alum alum alum PAC PAC PAC PAC PAC PAC PAC PAC PAC lime lime lime lime lime lime lime lime lime ferrous ferrous ferrous ferrous ferrous ferrous ferrous ferrous ferrous 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 Treatment Event Grass Grass Grass Grass Grass Grass Grass Grass Grass slurryonly slurryonly slurryonly slurryonly slurryonly slurryonly slurryonly slurryonly slurryonly 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 3.14 2.70 2.92 1.92 1.96 3.61 3.90 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 27.12 23.89 12.58 12.48 20.24 14.20 16.55 8.29 1.21 4.58 3.00 3.00 6.26 9.10 1.32 11.64 3.29 0.00 1.72 1.80 8.41 0.10 1.44 0.00 13.62 1.58 0.18 87.78 112.96 131.18 119.57 88.42 83.54 74.85 33.95 50.13 59.73 54.47 61.21 75.61 60.01 58.22 53.86 37.16 53.27 57.34 68.34 69.40 61.94 79.36 83.94 48.56 71.88 79.16 6.2817 8.6688 0.4569 1.7282 4.5567 0.2449 0.9945 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 6.2 1.9 0.5 2.4 0.9 15.4 11.6 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1737.1 1762.9 618.9 1349.5 1742.3 749.2 1237.2 1317.7 1312.7 1064.8 1476.4 1471.2 1114.0 1801.5 1967.8 1323.8 467.1 595.2 961.9 633.1 690.2 949.4 628.3 591.1 567.7 367.9 371.3 65.6 54.4 54.4 54.4 50.6 50.6 50.6 25.6 23.3 43.6 23.7 25.8 17.8 22.0 18.7 12.8 2.1 2.1 21.6 4.7 5.4 14.2 5.4 2.9 6.0 4.9 6.0 129.3 140.7 146.4 142.3 127.0 126.4 122.8 165.8 194.3 203.0 207.6 193.1 238.9 203.3 192.3 187.4 156.3 216.6 218.2 234.3 203.1 217.1 225.1 194.2 206.0 242.5 254.7 313.7 240.6 131.5 178.9 353.8 123.4 161.2 18.8 9.1 28.1 13.6 0.0 7.5 0.0 1.1 34.4 54.7 113.5 21.3 85.1 122.5 47.2 93.4 193.7 30.7 50.8 77.9 0.00 0.00 32.79 0.00 72.28 75.76 0 0 0 0 645.8 445.4 40.7 4.4 177.2 213.0 54.3 81.5 0.00 0.00 0.00 28.83 23.84 17.83 85.67 64.64 75.64 0 0 0 0 0 0 978.0 879.6 1010.5 89.0 78.0 98.0 207.0 215.5 213.2 19.6 21.6 17.5 Water extractable P of slurry at time of application mg/kg Slurry DM at time of application % 1.9364 1.9364 1.9364 1.7387 1.7387 1.7387 1.8468 1.8468 1.8468 10.56 10.49 10.4 197 19 21 13 19 14 10 12 17 10 20 29 8 15 17 10 20 29 12 17 27 12 14 29 8 16 19 6 16 20 5 12 17 6 16 pH runoff water 7.5 7.6 7.6 7.6 7.7 7.6 7.5 7.6 7.9 7.6 7.6 7.5 7.8 7.8 7.7 7.8 7.7 7.8 8 8 8 8 8 8 8 7.9 8 8 8 8 8 7.98 8 8.3 8 8 7.8 8 8 8 8 8 8 8.1 8 8 8 8 8 8 8.1 8.1 alum alum alum alum alum alum alum alum alum PAC PAC PAC PAC PAC PAC PAC PAC PAC lime lime lime lime lime lime lime lime lime ferrous ferrous ferrous ferrous ferrous ferrous ferrous ferrous ferrous 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1.8468 1.8468 1.8468 1.8468 1.8468 1.8468 0.0074 0.0074 0.0074 0.012 0.012 0.012 0.013 0.013 0.013 0.0094 0.0094 0.0094 0.0153 0.0153 0.0153 0.0124 0.0124 0.0124 0.0134 0.0134 0.0134 0.0171 0.0171 0.0171 0.0187 0.0187 0.0187 0.0159 0.0159 0.0159 9.4 9.6 9.3 9.3 9.63 9.86 8 8.6 9.8 10.25 10.16 198 7.5 7.4 7.5 7.44 7.4 7.6 7.47 7.5 7.5 7.9 7.9 7.9 7.8 7.8 7.8 7.9 7.9 7.9 7.4 7.5 7.45 7.4 7.5 7.6 7.6 7.6 7.6 7.7 7.8 7.8 7.5 7.5 7.5 7.8 7.8 7.8 Table C.2. Runoff box study flow weighted mean metal concentrations Fe Lime PAC alum Slurry RS Cd Cr Cu K Ni Pb Zn µg/l µg/l µg/l mg/l µg/l µg/l 1 0.8 (0.7) 4.8 (0.9) 42.7 (20.3) 43.5 (27.5) µg/l 15.5 (20) 2.7 (1) 274 (67) 2 0.6 (0.8) 3 (0.7) 45 (24.5) 64.6 (15.6) 7.9 (7.4) 8.3 (7.9) 337 (7) 3 0.4 (0.2) 3.2 (0.8) 32.9 (23) 62.6 (14) 3.8 (5.4) 4.9 (5.5) 383 (104) 1 0.9 (0.7) 2.7 (0.4) 20.6 (6.5) 122.5 (31.6) 3.9 (2.5) 8.3 (3.4) 1272 (549) 2 1.1 (0.2) 2.5 (0.5) 16.3 (6.6) 121.2 (9.2) 3.6 (4.2) 1.6 (1) 1244 (579) 3 0.6 (0.5) 3.2 (1) 17 (3.1) 82.3 (6.9) 1.9 (2.2) 9.3 (7.5) 1243 (497) 1 < limit < limit 4.7 (3.5) 47.9 (13) < limit < limit 1232 (145) 2 < limit < limit 2.2 (3.5) 63.7 (10.8) < limit < limit 1354 (208) 3 < limit < limit 7.4 (5.4) 57.4 (3.2) < limit < limit 1698 (344) 1 < limit < limit 1.7 (1.7) 49.3 (10.7) < limit < limit 674 (257) 2 < limit < limit 3.4 (4.4) 66.6 (4) < limit < limit 758 (169) 3 < limit < limit 5 (7.5) 70.6 (19.2) < limit < limit 596 (31) 1 < limit < limit 0.9 (1) 75.5 (5.5) < limit < limit 370 (23) 2 < limit < limit < limit < limit 16.4 (23.2) 24.8 (5.5) 74 (2.5) 75.6 (10.5) < limit < limit < limit < limit 546 (142) 978 (68) 1 1.2 (0.9) 2.2 (2.8) 19.9 (4.9) 24.7 (12.9) 0.7 (1.2) 4 (2.6) 369 (78) 2 0.9 (0.7) 1.3 (0.7) 10.5 (1.2) 19.7 (10.2) 2.8 (4.5) 6.8 (4.5) 431 (26) 3 1.2 (0.7) 1.9 (0.5) 14.2 (1.6) 18.1 (7.4) 1.4 (0.8) 9.4 (4.2) 664 (125) < limit 0.7 (0.1) 22.1 (1.5) 1.8 (0.1) 6.3 (3.2) < limit 613 (136) Grass 3 Tank 199 Table C.3 Runoff box study box nutrient concentrations (Chapter 4) Date 10-May Treatment alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass RS 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 Time after 0 min 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 pH runoff 7.44 7.39 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.6 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.7 7.6 7.6 Vol runoff mg 438 374 377 402 428 389 416 410 449 389 454 390 345 390 436 399 410 426 415 411 410 474 370 385 356 315 374 374 382 425 359 408 375 391 395 455 255 357 352 413 412 411 420 420 430 410 407 411 267 316 386 200 SS mg/l 393 419 459 430 404 383 228 427 325 340 138 372 276 288 308 280 253 261 224 255 199 218 224 202 410 476 365 302 218 326 251 357 226 237 211 189 288 305 102 357 184 204 227 327 350 150 200 125 131 206 84 DRP μg/l 189 188 174 224 152 177 157 174 171 181 171 162 149 161 149 165 187 198 199 210 177 207 196 221 153 168 194 198 192 206 215 188 192 224 231 225 177 174 175 168 164 187 147 145 166 172 203 159 198 175 158 PP μg/l 374 504 482 572 447 700 626 278 600 678 688 721 164 196 149 137 139 100 107 103 122 157 165 105 414 417 63 206 284 203 231 51 249 250 332 306 44 57 111 96 56 15 31 10 14 21 24 47 24 75 72 TP μg/l DUP μg/l 615 773 780 871 745 989 926 599 893 949 958 993 404 431 362 356 364 327 334 327 318 375 368 360 620 590 317 463 510 491 533 341 496 547 607 599 264 231 296 282 235 204 219 191 195 220 233 212 273 269 273 TDP μg/l 53 81 124 76 146 112 143 146 122 89 99 110 90 74 65 54 38 28 28 13 19 11 7 34 54 4 60 60 34 82 86 101 56 73 44 67 44 0 9 19 14 1 41 36 14 26 6 7 51 19 43 242 269 298 299 298 289 300 320 293 271 270 271 239 235 214 219 225 227 227 224 196 218 203 255 207 173 254 257 226 288 302 289 248 297 275 292 221 174 185 187 178 189 188 181 181 199 210 166 249 194 201 17-May10 Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 7.6 7.6 7.7 7.7 7.7 7.7 7.7 7.7 7.7 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 395 418 438 442 420 417 412 422 420 298 368 386 438 440 372 437 410 399 411 396 415 46 179 88 25 313 268 235 52 57 536 159 175 129 72 190 247 167 290 132 200 229 147 163 138 153 157 238 198 167 177 121 202 260 290 182 185 204 186 174 177 187 182 95 15 27 48 46 20 18 56 22 129 43 31 30 31 29 29 20 66 47 89 32 283 228 222 236 242 272 267 246 211 278 267 312 387 253 263 316 315 357 235 278 221 40 50 57 34 39 14 51 22 12 28 22 21 67 40 49 83 109 117 11 2 7 188 213 195 188 196 251 249 189 189 149 224 281 357 222 234 287 295 291 188 189 189 PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 353 345 374 363 384 384 398 398 383 383 380 380 307 391 381 390 335 335 386 386 444 444 382 382 347 340 321 374 369 369 367 367 374 374 377 377 197 225 367 392 219 390 570 570 550 550 750 750 290 450 320 240 220 440 290 290 280 280 350 350 180 410 940 390 280 280 320 320 530 530 430 430 23 89 86 85 75 75 82 82 26 26 82 82 90 33 86 26 87 87 30 30 86 86 91 91 69 73 24 82 28 28 84 84 58 58 37 37 1725 1850 1828 1915 1981 772 652 652 555 557 520 520 862 973 895 979 1126 1090 1156 1156 969 946 616 616 1183 1113 1035 1021 153 247 335 335 489 489 495 495 1981 2017 2100 2182 2245 1000 844 844 789 789 783 783 1107 1225 1251 1277 1367 1345 1424 1424 1234 1234 907 907 1384 1291 1256 1221 332 450 562 562 689 689 668 668 233 78 185 183 189 153 110 110 208 205 181 181 155 219 270 272 154 168 239 239 179 202 200 200 133 105 197 119 152 175 143 143 142 142 136 136 256 167 271 268 264 228 193 192 234 232 263 263 245 252 356 298 241 255 268 268 265 288 291 291 201 178 221 200 179 203 227 227 200 200 174 174 201 24-May10 slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 7.6 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 366 363 376 376 388 393 388 405 392 395 405 400 356 404 444 507 358 367 417 408 433 427 433 422 347 395 400 401 406 419 419 391 426 425 391 429 1933 4200 3267 5000 3333 4000 4133 4867 5533 5933 6600 5467 7300 5933 3509 5404 4759 3950 3600 5250 2500 4600 4000 4467 1640 1353 2238 1793 1231 1792 1950 750 2235 2467 1563 2000 701 636 766 837 874 992 944 1054 1055 1047 881 922 705 783 891 812 941 1050 1142 995 1003 1109 1193 799 176 128 305 346 305 389 341 376 441 431 403 423 947 1623 2982 4553 6157 7461 8867 10672 11213 11834 13760 12427 9595 9198 9996 10352 9902 11742 9206 9890 9154 6763 4697 12212 4286 4105 4465 4603 4950 5246 4108 4404 3703 3026 1760 5460 1791 2372 3861 5402 7050 8536 10230 12131 12751 13559 15754 14814 11196 10904 11668 12160 11707 13617 10919 11721 11003 8628 6606 13980 5038 4907 5251 5472 5798 6128 4913 5275 4572 3883 2658 6291 144 113 113 11 18 82 420 405 483 678 1113 1465 896 923 781 996 863 825 571 837 846 756 717 969 576 674 481 522 544 493 464 494 428 425 494 408 845 750 879 848 892 1074 1364 1459 1538 1725 1994 2387 1601 1706 1673 1808 1805 1875 1713 1831 1849 1865 1910 1768 752 802 786 869 848 881 805 871 869 856 898 831 Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 7.7 7.7 7.7 7.7 7.7 7.8 7.8 7.7 7.7 7.7 7.7 7.7 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 394 337 371 359 398 398 371 371 385 385 383 383 395 371 371 371 390 390 403 403 413 1600 1960 1280 1460 1580 1580 1740 1740 1560 1560 1620 1620 1500 1300 940 1400 1440 1440 1560 1560 1500 110 110 102 145 169 194 152 152 106 106 322 322 156 196 171 174 248 214 236 236 325 1647 2226 2513 2471 2643 2621 2612 2679 2699 2712 2733 2702 2349 2696 2788 2774 2376 2377 2400 2427 2562 2241 2925 3313 3313 3488 3488 3488 3488 3501 3501 3501 3501 3086 3395 3545 3545 3165 3165 3165 3165 3218 484 590 699 697 676 673 724 657 696 683 446 476 581 503 586 597 541 574 529 502 332 594 699 801 842 845 867 876 809 802 789 768 798 737 699 756 771 789 788 765 738 656 202 31-May10 Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 7.8 7.8 7.8 7.8 7.8 7.9 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 413 381 381 370 372 439 342 398 398 411 411 389 389 360 360 315 293 324 349 326 333 367 360 378 380 456 345 284 384 347 360 370 365 375 369 371 370 360 360 280 342 380 334 431 431 299 299 361 361 381 381 1500 1340 1340 760 460 1660 920 1000 1000 1120 1120 880 880 1180 1180 550 600 680 530 850 850 940 940 940 940 1110 1110 470 690 660 650 830 830 640 640 840 840 810 810 720 670 620 700 690 690 720 720 680 680 820 820 325 330 330 162 95 299 298 312 349 355 355 194 194 184 224 218 202 198 183 184 184 161 161 149 149 150 150 154 155 150 155 149 149 151 151 148 148 141 141 188 180 187 183 190 190 185 185 194 194 203 203 2450 2353 2345 1419 1661 1939 1924 1996 2015 1967 1941 1977 2022 2034 1997 1283 1153 1165 1158 1151 1461 1771 1771 1588 1569 1414 1414 1302 1241 946 886 827 935 1043 1043 1042 913 949 949 1029 984 918 1030 1142 1077 1012 1012 1111 1000 910 1003 3218 3218 3218 2062 2415 2711 2711 2796 2796 2756 2756 2823 2823 2823 2823 1616 1616 1703 1730 1758 2057 2355 2355 2134 2136 2000 2000 1857 1857 1539 1473 1406 1498 1591 1591 1498 1468 1500 1500 1441 1441 1345 1401 1456 1448 1440 1440 1567 1456 1456 1456 444 535 544 480 658 473 490 488 432 434 461 652 607 605 602 115 261 340 390 423 412 423 423 397 418 436 436 401 461 444 431 430 414 396 396 308 407 410 410 224 277 240 188 124 181 243 243 262 262 343 250 768 865 873 642 754 772 788 800 781 789 816 846 801 789 825 333 464 538 572 607 596 584 584 546 567 586 586 555 616 594 587 579 563 547 547 456 555 551 551 412 457 427 371 314 371 428 428 456 456 546 453 PAC PAC PAC PAC PAC PAC 1 1 1 1 1 1 2.5 7.5 12.5 17.5 22.5 27.5 7.9 7.9 7.9 7.9 7.9 7.9 352 356 386 383 431 431 360 250 467 404 923 900 101 106 103 65 130 130 886 825 1236 1589 1595 1688 1141 1133 1504 1876 1899 2000 154 202 165 222 174 182 256 307 269 287 305 312 203 PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC PAC 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.9 378 378 410 410 399 399 372 442 343 432 352 352 414 414 422 422 402 402 283 303 351 401 386 386 397 397 395 395 392 392 339 290 377 310 384 384 324 324 363 363 362 362 181 245 323 333 359 359 356 356 383 383 377 377 222 295 351 204 925 925 1000 1000 981 981 580 390 100 30 596 741 702 702 444 444 520 520 440 360 460 440 460 460 410 410 480 480 490 490 617 783 783 967 667 667 500 500 700 700 667 667 717 850 783 600 633 633 650 650 783 783 350 350 450 217 400 36 36 59 59 85 85 38 30 38 25 97 97 50 50 42 42 54 54 33 91 82 52 116 116 116 116 32 32 44 44 258 125 245 59 237 237 61 61 110 110 58 58 62 49 54 61 45 45 100 100 95 95 207 207 139 142 146 1618 1618 1155 1156 884 884 742 918 954 911 1044 972 818 818 849 896 1027 1027 762 1043 926 865 312 411 545 545 967 976 1637 1637 1410 1261 915 310 178 20 46 46 89 89 210 210 134 338 673 876 966 926 833 833 311 311 411 411 431 43 47 1938 1938 1500 1500 1268 1268 1043 1252 1213 1174 1312 1200 1006 1006 1050 1050 1133 1133 873 1154 1099 1043 497 600 739 739 1200 1200 1865 1865 2087 2046 1586 1127 943 760 760 760 823 823 956 956 926 1058 1295 1532 1586 1640 1640 1640 1300 1300 1479 1479 752 429 440 284 284 286 285 299 299 263 304 222 239 171 131 139 139 159 112 52 52 78 19 90 127 69 74 78 78 201 192 184 184 419 659 426 757 528 502 653 653 624 624 688 688 730 671 567 595 575 669 706 706 894 894 860 860 182 245 247 320 320 345 344 384 384 301 334 259 264 268 228 189 189 201 154 106 106 111 110 173 179 185 189 194 194 233 224 228 228 677 785 671 817 765 739 714 714 734 734 746 746 792 720 622 656 620 713 807 807 989 989 1068 1068 321 386 393 14-Jun10 PAC PAC PAC PAC PAC PAC PAC PAC PAC 3 3 3 3 3 3 3 3 3 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 7.8 7.7 7.8 7.8 7.8 7.8 7.8 7.8 7.8 332 366 366 368 368 395 395 379 379 617 617 433 433 517 583 583 517 517 171 176 176 157 157 177 177 181 181 113 189 246 228 228 477 477 504 504 502 576 650 650 650 900 900 909 909 218 212 229 265 265 246 246 225 225 389 387 405 422 422 423 423 405 405 alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 1 1 1 1 1 1 1 1 1 1 1 1 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 7.5 7.4 7.4 7.3 7.3 7.3 7.3 7.3 7.3 7.3 7.3 7.3 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.6 7.6 7.6 7.6 7.6 7.6 7.6 412 346 343 347 392 361 385 387 415 372 392 367 337 358 380 367 374 400 370 387 386 448 343 366 343 285 366 373 393 428 356 402 380 387 391 456 402 406 401 449 412 451 446 422 464 449 462 434 345 376 396 385 313 754 386 359 327 426 460 368 215 270 251 261 232 244 226 242 248 183 200 209 256 337 301 306 357 453 325 255 354 219 514 277 318 237 160 133 200 197 92 204 188 168 145 280 97 71 68 65 77 48 63 57 58 52 70 67 46 54 50 148 47 48 73 47 60 112 39 42 60 72 69 69 62 61 56 66 51 47 55 66 195 231 206 236 220 227 221 215 238 326 262 273 623 582 520 701 504 319 204 477 229 229 220 208 142 243 177 127 225 179 142 179 266 313 269 217 271 154 189 353 297 149 70 491 33 212 139 254 133 107 132 91 145 81 61 37 45 93 70 23 832 805 761 926 768 755 449 694 442 444 416 406 359 410 333 314 410 315 286 312 388 434 381 333 374 328 341 483 433 235 191 645 152 328 296 374 643 623 643 654 643 590 567 543 547 564 523 543 112 152 173 160 187 388 182 160 155 163 126 132 170 112 105 39 138 87 71 86 62 9 73 74 44 101 83 61 73 25 66 87 67 69 102 53 314 285 305 327 278 283 285 291 265 145 191 246 209 223 241 225 264 436 245 216 213 216 196 199 216 166 156 187 185 136 144 133 122 121 112 116 104 174 152 130 136 86 122 153 118 116 157 120 510 516 511 563 498 509 506 506 502 471 453 520 205 28-Jun10 Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 7.6 7.5 7.5 7.5 7.5 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.9 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 477 376 427 436 480 550 398 421 545 407 520 539 434 566 413 267 367 340 368 343 383 315 343 356 191 183 183 174 182 61 112 110 78 166 154 103 125 99 116 74 69 84 88 48 37 108 67 71 280 267 272 256 265 261 258 267 283 289 278 279 102 166 156 261 255 266 280 237 234 236 281 281 593 502 530 476 445 411 356 421 444 389 321 394 198 109 20 96 118 138 107 89 79 35 62 49 958 931 987 955 943 888 819 841 853 796 757 812 345 322 457 567 523 546 521 476 453 432 456 432 85 161 185 223 234 216 205 153 126 118 158 139 45 47 280 210 150 142 134 150 140 161 113 102 365 429 457 479 499 477 463 420 409 408 436 418 147 213 437 471 405 408 414 387 374 397 394 383 lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.45 7.4 7.44 7.45 7.5 7.5 7.5 7.6 7.4 374 418 460 456 532 385 478 453 466 476 463 439 287 396 349 358 370 360 414 392 323 362 376 265 348 380 390 390 386 403 404 384 415 691 698 696 1000 794 739 713 826 747 716 778 611 654 632 674 558 711 293 429 667 607 767 485 520 386 394 425 491 316 341 200 885 755 190 259 270 286 334 244 173 293 326 309 360 255 207 223 224 286 287 328 278 241 295 324 345 388 118 78 95 107 108 111 131 135 117 932 1080 1240 1159 965 1037 1171 1050 909 843 602 237 18 73 191 126 1215 1290 1383 1082 1220 183 267 80 136 333 87 118 114 58 152 128 484 1964 2112 2255 2081 1890 1994 2177 1922 1753 1524 1079 543 871 911 1040 974 1891 1957 2023 1862 1666 1835 1634 1564 529 493 566 620 729 639 663 662 1081 842 773 745 637 591 713 834 578 518 373 117 51 645 614 625 562 389 338 363 539 151 1328 1021 1096 275 83 384 395 507 470 380 399 480 1033 1032 1015 922 925 957 1007 871 844 681 477 306 853 837 849 848 676 666 640 780 446 1652 1367 1484 393 160 479 502 616 581 511 534 597 206 05-Jul-10 lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum 3 3 3 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 7.4 7.4 7.4 7.4 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.6 7.5 7.53 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.47 7.46 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.4 7.5 7.5 7.5 7.5 7.5 7.5 414 388 387 456 402 520 520 612 443 538 327 533 540 529 510 341 462 409 420 436 419 477 455 389 442 442 427 352 411 425 423 420 423 443 423 458 445 422 417 248 272 258 347 373 397 388 435 362 382 396 368 331 359 320 365 379 392 207 586 303 448 347 410 571 711 771 464 690 852 694 628 1044 439 500 517 619 581 736 733 732 699 787 674 543 684 786 633 435 263 468 383 588 431 404 229 735 667 478 485 580 554 625 531 553 523 575 543 500 476 333 556 722 505 427 727 133 139 98 210 231 242 200 278 202 304 285 253 368 297 282 216 177 192 193 122 173 206 162 173 219 248 263 62 66 81 76 80 81 80 75 83 89 95 145 58 46 79 48 46 43 58 47 43 52 56 59 126 66 74 69 84 80 680 39 86 157 863 751 1014 1080 518 1025 1101 837 688 1050 905 1041 1216 1200 1224 1072 1180 1149 1080 1103 1075 1042 1112 123 602 683 768 719 625 670 643 488 655 529 641 453 443 413 451 349 350 372 371 342 379 344 415 400 643 323 256 217 202 1232 575 531 968 1425 1507 1733 1886 1930 2156 2068 1995 1959 1930 1724 1845 1950 1991 1999 1900 1938 1910 1776 1848 1793 1722 1849 864 1022 1080 1220 1219 1074 1110 1163 870 1076 1066 1146 643 646 648 654 548 574 602 567 543 563 531 520 628 875 526 553 496 488 419 396 347 601 331 514 520 528 1210 828 683 905 902 583 537 588 557 599 582 706 586 555 534 572 499 432 474 679 354 316 376 420 368 359 445 299 331 443 359 133 156 156 155 153 181 172 149 158 133 131 46 102 167 128 228 194 206 551 535 445 811 562 756 720 806 1412 1131 967 1158 1271 880 819 804 734 791 775 828 759 761 696 744 718 680 736 741 420 397 451 500 449 439 520 382 421 538 505 191 202 235 202 199 224 231 196 201 185 187 105 228 233 202 297 278 286 07-Jul-10 alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum alum Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass Grass lime lime lime 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 1 1 1 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.5 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 361 387 404 336 384 385 392 250 338 387 386 413 404 380 447 375 389 405 326 384 351 390 394 392 397 400 408 364 416 389 295 433 381 382 397 412 427 398 408 404 417 411 335 393 356 409 416 362 414 394 403 408 389 409 366 295 381 208 529 500 660 254 551 446 309 371 624 467 378 544 167 212 143 486 638 420 286 213 370 240 253 267 301 302 300 433 344 256 158 88 138 45 25 76 23 42 170 100 216 48 63 85 134 50 33 95 95 115 68 85 130 43 550 367 850 81 85 89 91 94 105 73 89 84 83 84 86 115 99 97 90 97 87 67 71 69 75 82 77 74 76 194 102 77 81 79 72 75 77 83 84 106 100 65 109 122 130 48 44 68 75 79 113 81 96 89 82 95 145 280 105 132 216 204 248 253 291 301 85 31 147 145 160 78 101 146 37 107 182 248 166 187 206 228 172 144 74 59 74 56 58 93 90 91 101 85 83 86 66 63 74 60 73 45 138 88 89 46 22 11 34 31 40 54 66 8 405 304 461 480 484 453 476 526 525 391 393 388 383 436 378 400 402 367 377 394 425 352 372 401 424 375 347 293 281 288 223 256 265 278 271 269 246 244 227 198 206 206 192 209 177 233 176 186 168 145 156 179 187 167 165 198 166 1095 1030 1084 183 195 117 132 141 119 234 273 157 155 192 215 184 157 232 180 115 90 119 114 125 121 121 126 146 146 20 65 121 91 109 108 93 83 78 57 26 44 66 24 14 2 47 44 29 47 44 32 64 60 38 29 37 13 410 621 491 264 280 205 223 235 224 306 362 241 237 276 300 299 256 330 270 212 177 186 185 194 196 203 203 220 222 214 167 197 172 188 180 168 161 161 141 132 144 131 133 135 132 95 88 97 122 123 145 145 156 127 111 132 158 690 726 624 lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime lime slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.5 7.6 7.7 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.6 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.7 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 7.9 327 395 395 354 354 373 373 366 366 392 295 389 377 391 391 395 395 434 434 379 379 340 380 405 382 399 399 403 403 429 429 401 401 153 216 274 304 326 339 358 373 378 411 393 457 276 268 348 390 357 395 406 435 439 449 436 486 209 533 650 650 650 650 450 450 500 500 567 467 517 400 450 450 567 567 400 400 383 383 567 500 433 450 450 500 500 450 167 167 400 400 1067 1667 3000 2880 2900 3933 4200 2400 3733 3600 3267 3800 1950 3400 3300 3350 3050 3333 3533 3600 3267 4067 2600 4667 129 100 100 286 286 291 291 295 295 122 86 133 98 269 269 132 132 169 169 306 306 150 145 158 186 193 193 167 167 188 188 177 177 150 169 177 225 351 363 472 384 375 512 460 373 918 826 700 541 735 709 691 714 1166 867 1134 800 335 257 260 306 306 200 200 18 18 32 28 14 38 8 50 9 9 143 177 253 253 46 402 176 501 292 306 265 265 277 277 459 459 663 47 672 306 3892 5735 10434 11737 12089 10821 11021 10748 10786 4776 5785 8786 10025 9238 9341 9244 9054 6303 9224 6279 1139 1097 1055 1055 1055 1000 1000 863 863 410 790 628 566 629 713 713 713 800 834 926 926 211 929 901 873 928 983 983 983 1000 1000 1186 1186 1219 798 1686 1974 5565 7519 12419 13855 14089 12982 13890 13330 12350 6317 8099 11029 12592 11764 11279 11031 10603 8857 11022 8878 674 740 694 463 463 509 509 550 550 256 676 481 430 351 393 572 572 488 488 367 367 15 382 566 186 442 484 551 551 535 535 550 550 406 582 837 1443 1322 1421 1514 1735 1625 1649 2410 2209 646 715 1614 1702 1832 1817 1248 1073 383 1687 665 1799 803 840 794 749 749 800 800 845 845 378 762 613 528 621 662 704 704 657 657 673 673 165 526 725 372 635 677 718 718 723 723 727 727 556 751 1014 1668 1673 1784 1986 2119 2000 2161 2870 2582 1564 1541 2314 2243 2567 2526 1939 1787 1549 2554 1799 2599 12-Jul-10 slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry slurry Fe Fe Fe Fe Fe Fe Fe Fe Fe 3 3 3 3 3 3 3 3 3 3 3 3 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 1 1 1 1 1 1 1 1 1 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 7.7 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.7 7.7 7.7 7.7 7.7 7.7 7.7 7.7 7.9 7.9 7.9 7.9 7.9 7.7 7.7 7.7 7.7 7.9 7.7 7.8 7.6 7.7 7.7 7.7 7.7 7.7 7.7 7.7 7.7 7.7 7.7 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 235 334 335 400 312 384 399 426 409 480 446 488 320 334 357 364 380 379 385 390 384 438 347 398 342 298 384 412 376 401 413 415 411 421 403 420 330 381 405 434 345 405 411 413 415 429 409 407 360 323 348 345 371 371 342 342 356 210 3000 1575 1000 880 5480 2040 2200 2600 1250 1367 1833 1867 3050 3200 960 1080 1360 1233 1950 3550 2800 3150 2600 3300 1550 1257 4200 7333 1550 3150 3700 4867 4867 3800 3200 3400 1525 1200 2367 1800 2650 1667 1933 1467 1500 1833 1367 1400 670 670 620 660 700 700 860 860 960 868 984 1138 1077 1093 1057 1050 1134 1125 1130 1224 1309 574 529 72 40 166 430 517 557 538 649 758 850 256 340 271 280 491 368 390 448 517 609 777 682 410 364 369 495 482 556 514 466 619 558 543 334 256 95 272 272 277 280 274 274 256 4973 4168 3806 2338 2957 3191 4536 5369 3377 4483 4416 3596 11485 8524 796 1380 2470 3460 5202 6553 7400 10152 10881 11207 7439 8363 4052 5659 7138 7785 8233 7800 7690 6985 6176 8159 307 448 677 1992 1344 4779 4282 5711 4982 4619 4558 4682 1154 1333 1336 1314 1827 1847 1834 1851 2563 6049 5191 4994 4060 4692 5098 6247 6896 5324 6061 5858 5469 12084 9125 1528 2141 3287 4588 6520 7995 8951 11741 12506 12850 10819 12188 11596 11883 11550 11701 12245 11784 11642 10977 10100 12347 2589 2566 3225 4971 4930 6867 6902 7053 7209 6699 7076 6206 1745 1993 2150 2150 2668 2668 2668 2668 3417 208 39 50 645 642 850 661 393 822 448 218 564 25 72 660 721 651 698 800 885 1013 939 867 793 3124 3485 7273 5944 3921 3548 3622 3536 3435 3383 3147 3506 1872 1754 2179 2484 3104 1533 2106 876 1608 1522 1975 1190 336 564 541 563 564 541 560 543 598 1076 1023 1188 1722 1735 1907 1711 1527 1947 1578 1442 1873 599 601 732 761 817 1128 1317 1442 1551 1588 1625 1643 3380 3825 7544 6224 4412 3916 4012 3984 3952 3992 3924 4188 2282 2118 2548 2979 3586 2089 2620 1342 2227 2080 2518 1524 591 659 813 836 841 821 834 817 854 Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe Fe 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 3 3 3 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 2.5 7.5 12.5 17.5 22.5 27.5 32.5 37.5 42.5 47.5 52.5 57.5 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 7.8 356 349 349 362 334 334 352 355 355 361 361 373 373 342 342 324 330 396 311 365 365 370 370 377 377 380 380 211 960 1020 1020 1100 1760 980 1320 1240 1240 1280 1280 1280 1280 1280 1280 960 1420 1540 1080 540 540 900 900 560 560 1000 1000 256 152 152 312 292 273 271 292 300 289 289 315 315 176 176 319 333 332 342 350 290 369 369 224 224 182 182 2553 2585 2541 1575 1879 2266 2231 1835 1751 1785 1655 1838 1857 1968 1942 586 912 570 650 1241 1261 1582 1552 1594 1704 1655 1710 3417 3417 3417 2452 2615 2993 2993 2536 2536 2536 2536 2718 2718 2718 2718 1160 1445 1321 1321 1942 1942 2332 2332 2305 2305 2305 2305 608 680 724 565 444 455 491 409 485 462 592 565 546 574 601 255 199 419 329 351 391 381 411 487 377 468 412 864 832 877 877 736 728 762 701 785 751 882 880 861 750 777 574 533 751 671 701 681 750 780 711 601 650 594 Appendix D Results from Chapter 5 212 Table D.1 Ammonia emissions data mass N Cumulative runtime Run time Period mins hours mg/l mgN m2 mgN NH3-N loss kg/ha hourly KG HAmeasurement 1 period (mins) Slurry Slurry Slurry Alum Alum Alum Ferrous 1 120 120 2 45.56 29 3699 18 18 2 240 360 4 22.97 13 1703 4 4 3 1080 1440 18 44.83 26 3325 2 2 4 1440 2880 24 0.00 0 0 0 0 5 2880 5760 48 16.76 9 1215 0 0 6 4320 10080 72 0.00 0 0 0 0 1 120 120 2 31.99 20 2570 13 13 2 240 360 4 31.90 17 2234 6 6 3 1080 1440 18 52.33 30 3881 2 2 4 1440 2880 24 0.00 0 0 0 0 5 2880 5760 48 22.00 12 1577 0 0 6 4320 10080 72 0.00 0 0 0 0 1 120 120 2 33.49 21 2732 14 14 2 240 360 4 35.55 21 2637 7 7 3 1080 1440 18 45.97 27 3429 2 2 4 1440 2880 24 0.00 0 0 0 0 5 2880 5760 48 15.34 9 1112 0 0 6 4320 10080 72 0.00 0 0 0 0 1 120 120 2 0.41 0 33 0 0 2 240 360 4 1.14 1 83 0 0 3 1080 1440 18 3.22 2 236 0 0 4 1440 2880 24 0.00 0 0 0 0 5 2880 5760 48 7.40 4 549 0 0 6 4320 10080 72 0.00 0 0 0 0 1 120 120 2 0.67 0 54 0 0 2 240 360 4 2.42 1 156 0 0 3 1080 1440 18 4.04 2 250 0 0 4 1440 2880 24 0.00 0 0 0 0 5 2880 5760 48 5.33 3 389 0 0 6 4320 10080 72 0.00 0 0 0 0 1 120 120 2 0.39 0 32 0 0 2 240 360 4 13.77 8 1021 3 3 3 1080 1440 18 15.63 9 1159 1 1 4 1440 2880 24 0.00 0 0 0 0 5 2880 5760 48 6.59 4 473 0 0 6 4320 10080 72 0.26 0 14 0 0 1 120 120 2 9.39 6 774 4 4 2 240 360 4 16.64 11 1358 3 3 3 1080 1440 18 26.66 17 2175 1 1 213 Ferrous Ferrous Lime Lime Lime PAC PAC 4 1440 2880 24 35.60 21 2641 1 1 5 2880 5760 48 24.40 13 1639 0 0 6 4320 10080 72 3.55 2 226 0 0 1 120 120 2 7.00 4 574 3 3 2 240 360 4 18.86 12 1531 4 4 3 1080 1440 18 24.60 15 1895 1 1 4 1440 2880 24 39.62 22 2775 1 1 5 2880 5760 48 21.87 13 1649 0 0 6 4320 10080 72 2.88 1 154 0 0 1 120 120 2 9.92 6 817 4 4 2 240 360 4 23.51 15 1918 5 5 3 1080 1440 18 25.98 16 1991 1 1 4 1440 2880 24 36.88 22 2765 1 1 5 2880 5760 48 15.60 10 1285 0 0 6 4320 10080 72 2.51 1 149 0 0 1 120 120 2 115.47 73 9421 47 47 2 240 360 4 30.75 19 2496 6 6 3 1080 1440 18 18.58 11 1371 1 1 4 1440 2880 24 4.47 2 313 0 0 5 2880 5760 48 0.63 0 34 0 0 6 4320 10080 72 0.66 0 42 0 0 1 120 120 2 112.20 71 9108 46 46 2 240 360 4 33.94 22 2769 7 7 3 1080 1440 18 11.84 7 927 1 1 4 1440 2880 24 4.80 3 334 0 0 5 2880 5760 48 0.47 0 33 0 0 6 4320 10080 72 0.01 0 0 0 0 1 120 120 2 79.14 50 6457 32 32 2 240 360 4 25.26 15 1977 5 5 3 1080 1440 18 15.10 9 1182 1 1 4 1440 2880 24 4.92 3 345 0 0 5 2880 5760 48 0.17 0 12 0 0 6 4320 10080 72 4.14 2 278 0 0 1 120 120 2 4.50 3 365 2 2 2 240 360 4 9.07 6 732 2 2 3 1080 1440 18 25.48 15 1963 1 1 4 1440 2880 24 35.97 20 2609 1 1 5 2880 5760 48 22.52 12 1596 0 0 6 4320 10080 72 7.18 3 361 0 0 1 120 120 2 8.42 5 694 3 3 2 240 360 4 14.97 10 1221 3 3 3 1080 1440 18 27.44 16 2103 1 1 4 1440 2880 24 41.35 24 3067 1 1 214 Char Char Charcoal Soil Only Soil Only Soil Only 5 2880 5760 48 25.71 16 2013 0 0 6 4320 10080 72 7.29 4 453 0 0 1 120 120 2 9.46 6 780 4 4 2 240 360 4 13.55 9 1116 3 3 3 1080 1440 18 14.69 9 1186 1 1 4 1440 2880 24 11.07 7 894 0 0 5 2880 5760 48 0.00 0 0 0 0 6 4320 10080 72 3.89 2 288 0 0 1 120 120 2 1.74 1 143 1 1 2 240 360 4 10.05 6 820 2 2 3 1080 1440 18 10.01 6 825 0 0 4 1440 2880 24 5.44 3 440 0 0 5 2880 5760 48 1.12 1 91 0 0 6 4320 10080 72 4.23 3 342 0 0 1 120 120 2 2.93 2 241 1 1 2 240 360 4 9.98 6 822 2 2 3 1080 1440 18 19.55 12 1563 1 1 4 1440 2880 24 11.74 6 813 0 0 5 2880 5760 48 5.61 3 448 0 0 6 4320 10080 72 0.76 0 52 0 0 1 120 120 2 0.00 0 0 0 0 2 240 360 4 0.09 0 7 0 0 3 1080 1440 18 0.00 0 0 0 0 4 1440 2880 24 0.00 0 0 0 0 5 2880 5760 48 0.00 0 0 0 0 6 4320 10080 72 0.00 0 0 0 0 1 120 120 2 0.00 0 0 0 0 2 240 360 4 0.01 0 1 0 0 3 1080 1440 18 0.00 0 0 0 0 4 1440 2880 24 0.00 0 0 0 0 5 2880 5760 48 0.00 0 0 0 0 6 4320 10080 72 0.00 0 0 0 0 1 120 120 2 0.92 1 76 0 0 2 240 360 4 0.00 0 0 0 0 3 1080 1440 18 0.06 0 5 0 0 4 1440 2880 24 0.00 0 0 0 0 5 2880 5760 48 0.00 0 0 0 0 6 4320 10080 72 0.00 0 0 0 0 215 Table D.2 Nitrous oxide flux Nitrous oxide Atmospheric pressure ppb g N2O 1014.4 -1 - g ha hr 28 Slurry 26 Slurry 27 Slurry Time Temp RH DewPt (hr) °C 23.1 24.4 22.3 20.8 22.3 18.1 22.7 22.5 17.7 22 20.9 21.1 24 23.1 23.8 23.9 24.1 23.3 0 23.1 24.4 22.3 20.8 22.3 18.1 22.7 22.5 17.7 22 20.9 21.1 24 23.1 23.8 23.9 24.1 23.3 0 23.1 24.4 22.3 20.8 22.3 18.1 22.7 22.5 17.7 22 20.9 21.1 % 32 31 35 35 42 44 38 38 41 32 32 35 37 39 34 32 33 31 °C -1 0 6 24 48 72 96 144 168 192 216 240 264 312 336 360 384 408 -1 0 6 24 48 72 96 144 168 192 216 240 264 312 336 360 384 408 -1 0 6 24 48 72 96 144 168 192 216 240 0 1 2 3 4 ppm 0.25 1.25 3.14 6.56 1.84 1.18 0.45 1.23 0.8 1.15 0.77 2.08 0.57 1.03 4.64 1.22 1.87 1.18 0.03 0.73 0.84 0.99 0.83 0.75 0.06 0.57 0.65 0.77 0.54 0.98 0.75 0.51 1 0.88 0.69 0.61 N2O -2 -1 μg m h 22.8 113.1 285.1 599.6 167.4 109 40.8 111.7 74.2 104.8 70.1 190 51.5 93.5 419.9 110.1 168.5 106.5 0.55 0.58 0.56 0.11 0.89 2.69 9.95 -0.52 3.65 4.28 1 2.93 3.58 2.66 1.69 1.21 1.15 1.89 0.95 1.34 1.3 0.02 0.41 0.98 0.98 0.33 0.77 0.97 0.53 0.97 0.87 0.84 0.84 0.91 0.34 0.6 0.62 0.69 0.9 10.3 80.7 244.3 908.6 -46.9 336.3 388.3 90.5 270.8 325.3 242.7 154.4 109.5 103.9 170.9 85.7 121.4 117.9 0.1 0.81 2.44 9.09 -0.47 3.36 3.88 0.9 2.71 3.25 2.43 1.54 1.1 1.04 1.71 0.86 1.21 1.18 0.53 0.41 0.65 1.66 0.98 0.61 0.6 0.46 0.51 0.51 0.51 0.55 0.89 -0.35 1.6 10.86 5.74 0.35 0.29 0.02 0.4 0.23 0.4 -0.25 0.72 0.07 0.93 1 0.97 0.02 0.04 0 0.55 0.08 0.21 0.44 80.5 -31.4 145 991.9 521.3 32.1 26.7 1.6 37.1 20.7 36.7 -23 0.8 -0.31 1.45 9.92 5.21 0.32 0.27 0.02 0.37 0.21 0.37 -0.23 h 5.7 6.6 6.5 5 8.9 5.9 8.1 7.7 4.4 5 3.8 5.5 8.9 8.8 7.3 6.5 7.1 5.7 0.53 0.47 0.58 0.81 0.54 0.53 0.58 0.55 0.53 0.5 0.53 0.52 0.5 0.53 0.59 0.52 0.49 0.48 0.56 0.45 0.7 0.88 0.58 0.54 0.51 0.52 0.54 0.56 0.58 0.55 0.51 0.54 0.66 0.54 0.51 0.54 0.55 0.48 0.74 1.01 0.56 0.53 0.53 0.57 0.59 0.55 0.55 0.6 0.53 0.59 0.75 0.57 0.55 0.51 0.62 0.5 0.81 1.14 0.65 0.59 0.59 0.56 0.56 0.56 0.6 0.63 0.52 0.54 0.82 0.56 0.64 0.55 0.52 0.55 0.79 1.23 0.66 0.61 32 31 35 35 42 44 38 38 41 32 32 35 37 39 34 32 33 31 5.7 6.6 6.5 5 8.9 5.9 8.1 7.7 4.4 5 3.8 5.5 8.9 8.8 7.3 6.5 7.1 5.7 0.54 0.51 0.58 0.89 0.46 0.46 0.59 0.48 0.52 0.6 0.48 0.49 0.54 0.5 0.38 0.5 0.51 0.48 0.49 0.47 0.62 1.08 0.46 0.58 0.61 0.44 0.54 0.58 0.58 0.49 0.56 0.53 0.46 0.51 0.52 0.48 0.55 0.56 0.66 1.26 0.49 0.58 0.72 0.5 0.59 0.67 0.61 0.51 0.56 0.61 0.51 0.56 0.58 0.5 0.53 0.54 0.73 1.45 0.44 0.75 0.78 0.53 0.64 0.79 0.62 0.59 0.6 0.62 0.47 0.56 0.61 0.54 0.53 0.55 0.75 1.53 0.43 0.68 0.86 0.51 0.71 0.79 32 31 35 35 42 44 38 38 41 32 32 35 5.7 6.6 6.5 5 8.9 5.9 8.1 7.7 4.4 5 3.8 5.5 0.49 0.44 0.54 0.93 0.62 0.52 0.54 0.48 0.48 0.51 0.48 0.57 0.47 0.45 0.56 1.11 0.66 0.57 0.58 0.45 0.5 0.46 0.52 0.55 0.52 0.5 0.57 1.3 0.82 0.56 0.62 0.49 0.51 0.5 0.49 0.56 0.53 0.46 0.6 1.46 0.9 0.44 0.52 0.5 0.5 0.49 0.54 0.54 216 0.63 0.59 0.6 0.58 0.65 0.54 0.61 0.61 0.58 0.58 0.62 0.55 R² 1 -1 0.23 1.13 2.85 6 1.67 1.09 0.41 1.12 0.74 1.05 0.7 1.9 0.52 0.94 4.2 1.1 1.69 1.07 264 312 336 360 384 408 31 Alum -1 0 6 24 48 72 96 144 168 192 216 240 264 312 336 360 384 408 30 Alum -1 0 6 24 48 72 96 144 168 192 216 240 264 312 336 360 384 408 32 Alum -1 0 6 24 48 72 96 144 168 192 216 240 24 23.1 23.8 23.9 24.1 23.3 0 23.1 24.4 22.3 20.8 22.3 18.1 22.7 22.5 17.7 22 20.9 21.1 24 23.1 23.8 23.9 24.1 23.3 0 23.1 24.4 22.3 20.8 22.3 18.1 22.7 22.5 17.7 22 20.9 21.1 24 23.1 23.8 23.9 24.1 23.3 0 23.1 24.4 22.3 20.8 22.3 18.1 22.7 22.5 17.7 22 20.9 21.1 37 39 34 32 33 31 8.9 8.8 7.3 6.5 7.1 5.7 0.58 0.47 0.52 0.53 0.47 0.57 0.54 0.49 0.51 0.5 0.46 0.5 0.53 0.51 0.5 0.56 0.48 0.55 0.51 0.56 0.54 0.54 0.49 0.54 0.52 0.51 0.57 0.51 0.55 -0.85 0.94 0.39 0.68 0.66 0.04 0.7 0.55 0.18 0.49 0.87 0 -76.5 85.4 35.3 61.8 59.6 3.8 -0.76 0.85 0.35 0.62 0.6 0.04 32 31 35 35 42 44 38 38 41 32 32 35 37 39 34 32 33 31 5.7 6.6 6.5 5 8.9 5.9 8.1 7.7 4.4 5 3.8 5.5 8.9 8.8 7.3 6.5 7.1 5.7 0.51 0.44 0.66 1.1 0.87 0.63 0.66 0.79 0.56 0.68 0.52 0.58 0.49 0.49 0.47 0.58 0.68 0.69 0.58 0.51 0.69 1.4 1.11 0.86 0.93 1.02 0.72 0.8 0.53 0.62 0.61 0.55 0.52 0.54 0.7 0.81 0.58 0.49 0.83 1.69 1.32 1.19 1.18 1.71 0.89 0.9 0.61 0.64 0.63 0.58 0.51 0.53 0.74 0.83 0.52 0.55 0.85 1.97 1.56 1.46 1.41 2.07 1.05 1.04 0.65 0.7 0.61 0.61 0.54 0.6 0.79 0.9 0.51 0.66 0.93 2.25 1.74 1.76 1.62 2.52 1.18 1.08 0.71 0.71 0.67 0.69 0.55 0.61 0.83 0.71 -0.38 2.84 4.26 17.22 13.1 17.17 14.39 27.02 9.37 6.23 2.95 2.11 2.11 2.77 1.09 0.66 2.29 0.75 0.07 0.81 0.96 1 1 1 1 0.98 1 0.98 0.97 0.96 0.73 0.97 0.86 0.25 0.98 0.05 -34.3 256 387.1 1572.9 1191 1582.7 1306.5 2454.4 865.1 567.1 269 192.7 190.3 251.2 98.2 59.6 206.5 67.9 -0.34 2.56 3.87 15.73 11.91 15.83 13.06 24.54 8.65 5.67 2.69 1.93 1.9 2.51 0.98 0.6 2.06 0.68 32 31 35 35 42 44 38 38 41 32 32 35 37 39 34 32 33 31 5.7 6.6 6.5 5 8.9 5.9 8.1 7.7 4.4 5 3.8 5.5 8.9 8.8 7.3 6.5 7.1 5.7 0.58 0.49 0.73 0.68 0.65 0.74 0.61 0.6 0.51 0.41 0.55 0.55 0.51 0.61 0.71 0.49 0.57 0.57 0.62 0.42 0.82 0.91 0.72 0.8 0.74 0.89 0.6 0.49 0.6 0.6 0.62 0.76 0.99 0.68 0.64 0.63 0.67 0.66 0.83 0.91 0.77 0.84 0.81 0.9 0.59 0.61 0.6 0.68 0.62 0.87 1.28 0.71 0.74 0.69 0.64 0.79 0.91 1.03 0.81 0.91 0.87 0.9 0.69 0.66 0.62 0.73 0.7 0.9 1.42 0.86 0.82 0.74 0.63 0.91 0.92 1.11 0.88 0.99 0.9 0.77 7.29 2.84 5.85 3.29 3.7 4.18 5.37 2.96 4.92 0.7 3.84 3.65 5.89 3.67 6.19 3.98 3.79 0.36 0.89 0.93 0.91 0.99 0.99 0.94 0.61 0.91 0.99 0.6 0.99 0.95 0.96 0.1 0.96 0.91 0.99 69.6 657.7 257.9 534.3 299.4 340.8 379 487.7 273.1 447.6 64.1 350.3 330.2 534 332 559.1 359.3 342.9 0.7 6.58 2.58 5.34 2.99 3.41 3.79 4.88 2.73 4.48 0.64 3.5 3.3 5.34 3.32 5.59 3.59 3.43 32 31 35 35 42 44 38 38 41 32 32 35 5.7 6.6 6.5 5 8.9 5.9 8.1 7.7 4.4 5 3.8 5.5 0.72 0.72 0.8 0.73 0.49 0.59 0.57 0.53 0.56 0.61 0.51 0.44 0.85 0.8 0.93 0.77 0.58 0.64 0.58 0.52 0.54 0.64 0.52 0.47 0.95 0.99 1.01 0.93 0.61 0.67 0.61 0.65 0.56 0.64 0.53 0.5 0.97 0.99 1.17 0.9 0.64 0.7 0.7 0.64 0.57 0.65 0.54 0.51 1.01 1.14 1.27 0.94 0.69 0.69 0.68 0.69 0.6 0.65 0.56 4.24 6.15 7.12 3.31 2.77 1.59 1.96 2.62 0.62 0.51 0.65 1.4 0.91 0.95 0.99 0.8 0.96 0.83 0.82 0.83 0.55 0.78 0.96 0.99 383.9 554.9 647.2 302.5 251.9 146.6 178.1 237.6 57.6 46.4 59.2 127.5 3.84 5.55 6.47 3.03 2.52 1.47 1.78 2.38 0.58 0.46 0.59 1.28 217 0.71 0.74 0.6 0.8 0.77 1.03 0.8 0.92 0.81 0.83 264 312 336 360 384 408 23 FeCl 24 FeCl 18 FeCl -1 0 2 8 24 48 96 192 216 240 312 336 360 384 408 504 528 552 576 -1 0 2 8 24 48 96 192 216 240 312 336 360 384 408 504 528 552 576 -1 0 2 8 24 48 96 192 216 240 24 23.1 23.8 23.9 24.1 23.3 0 21.1 19.7 19.7 24 24.3 23.8 23.8 22.7 21.6 22.4 23.2 22.9 23.4 22.5 22.5 22.3 22.1 21.9 22.9 0 21.1 19.7 19.7 24 24.3 23.8 23.8 22.7 21.6 22.4 23.2 22.9 23.4 22.5 22.5 22.3 22.1 21.9 22.9 0 21.1 19.7 19.7 24 24.3 23.8 23.8 22.7 21.6 22.4 37 39 34 32 33 31 8.9 8.8 7.3 6.5 7.1 5.7 0.58 0.55 0.66 0.48 0.47 0.5 0.54 0.65 0.86 0.5 0.52 0.53 0.53 0.68 0.89 0.57 0.62 0.56 0.6 0.72 0.99 0.52 0.54 0.54 0.61 0.75 35 40 42 37 38 34 29 27 27 29 33 32 30 30 30 29 28 31 27 5.5 6 6.8 8.9 9.3 7.3 4.8 3 2 4 6.5 5.4 5 4.4 4.5 4.3 4.4 5.1 3.9 0.56 0.57 0.54 0.47 0.63 0.64 0.87 0.59 0.47 0.51 0.53 0.53 0.47 0.47 0.47 0.62 0.46 0.44 0.48 0.52 0.6 0.53 0.52 0.71 0.78 1.15 0.65 0.51 0.55 0.58 0.59 0.54 0.51 0.47 0.6 0.49 0.46 0.46 0.54 0.64 0.54 0.52 0.76 0.88 1.38 0.65 0.57 0.52 0.56 0.59 0.51 0.48 0.51 0.63 0.49 0.49 0.54 0.55 0.71 0.54 0.5 0.86 1.01 1.71 0.73 0.58 0.6 0.57 0.63 0.52 0.49 0.53 0.62 0.5 0.51 0.5 0.56 35 40 42 37 38 34 29 27 27 29 33 32 30 30 30 29 28 31 27 5.5 6 6.8 8.9 9.3 7.3 4.8 3 2 4 6.5 5.4 5 4.4 4.5 4.3 4.4 5.1 3.9 0.52 0.62 0.56 0.5 0.68 0.79 0.73 0.59 0.46 0.48 0.45 0.49 0.46 0.48 0.45 0.58 0.51 0.46 0.44 0.47 0.59 0.57 0.53 0.78 0.97 0.97 0.55 0.47 0.54 0.53 0.53 0.51 0.5 0.52 0.56 0.46 0.43 0.47 0.52 0.58 0.62 0.56 0.87 1.06 1.15 0.57 0.43 0.5 0.48 0.5 0.46 0.49 0.5 0.55 0.52 0.48 0.49 0.53 0.69 0.58 0.53 0.93 1.26 1.39 0.5 0.47 0.48 0.51 0.53 0.47 0.5 0.45 0.57 0.52 0.53 0.49 0.56 0.77 0.63 0.56 1.04 1.38 1.58 35 40 42 37 38 34 29 27 27 29 5.5 6 6.8 8.9 9.3 7.3 4.8 3 2 4 0.48 0.6 0.56 0.52 0.77 0.63 0.42 0.54 0.49 0.45 0.47 0.64 0.57 0.56 0.87 0.85 0.62 0.55 0.52 0.47 0.51 0.6 0.57 0.57 1.01 1.12 0.8 0.59 0.52 0.5 0.54 0.63 0.62 0.57 1.07 1.29 0.95 0.58 0.49 0.51 0.56 0.65 218 0.6 0.57 0.56 0.55 0.9 1.14 1.99 1.14 0.61 1.14 0.57 0.49 0.49 0.49 0.5 0.49 1.38 0.55 1.38 0.52 0.47 0.49 0.53 0.51 0.43 0.61 1.24 1.52 1.18 0.68 1.52 0.53 0.66 2.74 6.08 1.55 1.31 0.75 0.25 0.91 0.89 0.71 0.4 0.46 59.6 248.5 550.2 139.9 118.1 67.9 0.6 2.48 5.5 1.4 1.18 0.68 0.13 2.7 0.35 0.97 4.19 7.37 16.79 2.45 8.43 1.51 0.7 7.6 1.1 0.08 0.59 0.19 0.43 0.98 0.29 0.04 0.95 0.44 0.62 0.98 1 1 0.87 0.66 0.73 0.39 0.64 0.62 0.02 0.42 0.14 0.57 0.87 0.07 11.5 247.6 32.5 87.8 378 666.3 1517.7 222.1 768 136.8 63.1 688.9 99.9 7.1 53.4 17.4 39.3 89.6 26.1 0.11 2.48 0.32 0.88 3.78 6.66 15.18 2.22 7.68 1.37 0.63 6.89 1 0.07 0.53 0.17 0.39 0.9 0.26 0.78 2.35 0.83 0.72 5.19 8.76 12.79 -1.45 11.09 0.39 0.94 10.67 0.46 -0.12 0.11 -0.25 0.65 1.22 0.04 0.4 0.61 0.51 0.53 0.99 0.99 1 0.67 0.5 0.1 0.28 0.52 0.21 0.07 0.01 0.2 0.4 0.65 0 71.2 215.7 76.5 65.1 468.5 792.1 1156.5 -131.8 1010.7 35.4 85.3 967.5 41.8 -10.9 10.4 -22.9 58.9 110.9 3.8 0.71 2.16 0.76 0.65 4.68 7.92 11.56 -1.32 10.11 0.35 0.85 9.67 0.42 -0.11 0.1 -0.23 0.59 1.11 0.04 1.4 0.52 0.95 1.24 6.82 13.36 11.14 1.9 12.14 1.24 0.9 0.43 0.76 0.85 0.98 1 1 0.79 0.5 0.97 128.1 47.9 87.5 111.7 615.2 1207.7 1006.7 172.6 1106.3 112.8 1.28 0.48 0.87 1.12 6.15 12.08 10.07 1.73 11.06 1.13 312 336 360 384 408 504 528 552 576 17 Lime 21 Lime 19 Lime -1 0 2 8 24 48 96 192 216 240 264 336 360 384 432 528 552 576 600 -1 0 2 8 24 48 96 192 216 240 264 336 360 384 432 528 552 576 600 -1 0 2 8 24 48 96 23.2 22.9 23.4 22.5 22.5 22.3 22.1 21.9 22.9 0 21.1 19.7 19.7 24 24.3 23.8 23.8 22.7 21.6 22.4 23.2 22.9 23.4 22.5 22.5 22.3 22.1 21.9 22.9 0 21.1 19.7 19.7 24 24.3 23.8 23.8 22.7 21.6 22.4 23.2 22.9 23.4 22.5 22.5 22.3 22.1 21.9 22.9 0 21.1 19.7 19.7 24 24.3 23.8 23.8 33 32 30 30 30 29 28 31 27 6.5 5.4 5 4.4 4.5 4.3 4.4 5.1 3.9 0.44 0.54 0.48 0.5 0.45 0.5 0.44 0.87 0.46 0.48 0.51 0.51 0.47 0.49 0.52 0.49 0.46 0.47 0.48 0.57 0.47 0.5 0.48 0.52 0.48 0.46 0.5 0.55 0.55 0.51 0.51 0.49 0.51 0.51 0.47 0.48 35 40 42 37 38 34 29 27 27 29 33 32 30 30 30 29 28 31 27 5.5 6 6.8 8.9 9.3 7.3 4.8 3 2 4 6.5 5.4 5 4.4 4.5 4.3 4.4 5.1 3.9 0.48 0.63 0.58 0.56 0.87 0.55 0.42 0.44 0.46 0.52 0.48 0.51 0.54 0.47 0.49 0.49 0.47 0.48 0.47 0.47 0.7 0.58 0.59 0.95 0.63 0.49 0.53 0.56 0.51 0.46 0.47 0.5 0.49 0.46 0.52 0.51 0.49 0.46 0.51 0.7 0.59 0.63 1.07 0.66 0.54 0.53 0.49 0.47 0.48 0.47 0.48 0.41 0.53 0.54 0.53 0.45 0.51 0.54 0.74 0.64 0.64 1.24 0.74 0.51 0.51 0.54 0.5 0.47 0.51 0.47 0.53 0.5 0.52 0.47 0.48 0.46 0.56 35 40 42 37 38 34 29 27 27 29 33 32 30 30 30 29 28 31 27 5.5 6 6.8 8.9 9.3 7.3 4.8 3 2 4 6.5 5.4 5 4.4 4.5 4.3 4.4 5.1 3.9 0.49 0.58 0.54 0.53 0.75 0.53 0.42 0.47 0.43 0.44 0.45 0.51 0.5 0.43 0.45 0.58 0.46 0.53 0.44 0.5 0.6 0.52 0.53 0.77 0.55 0.51 0.51 0.47 0.51 0.5 0.52 0.49 0.49 0.46 0.56 0.54 0.5 0.52 0.5 0.69 0.57 0.59 0.86 0.64 0.5 0.47 0.45 0.46 0.49 0.54 0.54 0.5 0.47 0.55 0.57 0.5 0.44 0.49 0.68 0.59 0.57 0.98 0.68 0.51 0.49 0.48 0.52 0.55 0.55 0.54 0.49 0.52 0.57 0.55 0.51 0.48 0.55 0.71 0.64 0.63 1.03 0.77 0.47 0.59 0.48 0.49 0.48 0.58 0.53 0.5 0.53 35 40 42 37 38 34 29 5.5 6 6.8 8.9 9.3 7.3 4.8 0.52 0.52 0.53 0.55 0.68 0.45 0.37 0.52 0.57 0.57 0.56 0.66 0.45 0.49 0.48 0.61 0.6 0.57 0.74 0.52 0.5 0.51 0.65 0.63 0.59 0.75 0.5 0.47 219 2.09 11.95 0.78 0.11 0.52 0.19 0.91 -4.4 -0.15 0.89 0.52 0.45 0.03 0.74 0.2 0.75 0.42 0.04 189.7 1083.9 70.6 9.8 47.4 16.9 82.9 -400.8 -13.6 1.9 10.84 0.71 0.1 0.47 0.17 0.83 -4.01 -0.14 1.4 1.97 1.18 3.38 7.34 3.26 1.24 0.73 0.71 0.38 -0.05 0.25 -0.34 0.65 0.54 0.67 0.79 0.46 0.2 0.9 0.89 0.85 0.8 0.99 0.98 0.53 0.27 0.22 0.1 0.01 0.1 0.09 0.15 0.23 0.52 0.31 0.21 0.06 128.1 180.5 108.4 305.3 662.4 295.2 112.3 66.4 64.5 34.3 -4.3 22.9 -30.4 58.9 49 60.5 72 41.5 18.5 1.28 1.8 1.08 3.05 6.62 2.95 1.12 0.66 0.65 0.34 -0.04 0.23 -0.3 0.59 0.49 0.61 0.72 0.42 0.19 0.57 0.53 0.46 0.66 2.02 1.53 1.48 4.57 3.65 0.62 1.33 0.71 0.67 0.64 0.97 0.65 0.85 1.37 -0.25 1.38 -0.01 -0.13 0.45 0.85 0.81 0.82 0.95 0.96 0.19 0.53 0.65 0.28 0.24 0.93 0.52 0.54 0.92 0.2 0.64 0 0.01 60.2 184.9 140.3 133.9 412.7 329.9 56.4 120.9 64.5 61 57.6 88.2 58.7 77.4 124.2 -22.9 125.5 -1.1 -11.4 0.6 1.85 1.4 1.34 4.13 3.3 0.56 1.21 0.65 0.61 0.58 0.88 0.59 0.77 1.24 -0.23 1.26 -0.01 -0.11 0.48 0.63 0.64 0.58 0.79 0.6 0.52 -0.55 1.74 1.67 0.47 1.86 2.14 1.75 0.51 0.86 0.98 0.74 0.8 0.79 0.58 -49.8 159.6 152.9 42.3 167.9 193.2 158.4 -0.5 1.6 1.53 0.42 1.68 1.93 1.58 1.52 0.55 0.48 0.5 0.51 0.49 0.45 0.65 0.81 1.33 0.77 0.52 0.52 0.54 0.56 0.47 0.51 0.53 0.51 0.52 0.56 0.52 0.48 192 216 240 264 336 360 384 432 528 552 576 600 PAC PAC Char 27 27 29 33 32 30 30 30 29 28 31 27 3 2 4 6.5 5.4 5 4.4 4.5 4.3 4.4 5.1 3.9 0.59 0.44 0.48 0.49 0.55 0.49 0.51 0.46 0.48 0.43 0.46 0.47 0.57 0.49 0.53 0.54 0.49 0.47 0.49 0.47 0.56 0.49 0.48 0.46 0.47 0.47 0.52 0.54 0.53 0.5 0.47 0.5 0.54 0.54 0.48 0.49 0.52 0.53 0.48 0.47 0.53 0.52 0.48 0.46 0.55 0.52 0.45 0.46 0.54 0.52 0.49 0.51 0.57 0.5 0.47 0.48 32 31 35 35 42 44 38 38 41 32 32 35 37 39 34 32 33 31 5.7 6.6 6.5 5 8.9 5.9 8.1 7.7 4.4 5 3.8 5.5 8.9 8.8 7.3 6.5 7.1 5.7 0.6 0.54 0.53 0.78 0.43 0.36 0.52 0.42 0.52 0.45 0.52 0.49 0.49 0.49 0.49 0.52 0.53 0.48 0.73 0.54 0.54 0.9 0.55 0.5 0.52 0.52 0.51 0.48 0.48 0.46 0.49 0.54 0.52 0.51 0.5 0.48 0.78 0.58 0.54 1.01 0.65 0.54 0.51 0.53 0.47 0.5 0.53 0.53 0.5 0.52 0.54 0.49 0.5 0.48 0.87 0.58 0.56 1.2 0.76 0.63 0.54 0.49 0.5 0.51 0.54 0.56 0.51 0.51 0.52 0.53 0.51 0.44 0.93 0.58 0.6 1.3 0.84 0.73 0.49 0.58 0.56 0.55 0.58 0.54 0.51 0.54 -1 0 6 24 48 72 96 144 168 192 216 240 264 312 336 360 384 408 22.7 21.6 22.4 23.2 22.9 23.4 22.5 22.5 22.3 22.1 21.9 22.9 0 23.1 24.4 22.3 20.8 22.3 18.1 22.7 22.5 17.7 22 20.9 21.1 24 23.1 23.8 23.9 24.1 23.3 0 23.1 24.4 22.3 20.8 22.3 18.1 22.7 22.5 17.7 22 20.9 21.1 24 23.1 23.8 23.9 24.1 23.3 32 31 35 35 42 44 38 38 41 32 32 35 37 39 34 32 33 31 5.7 6.6 6.5 5 8.9 5.9 8.1 7.7 4.4 5 3.8 5.5 8.9 8.8 7.3 6.5 7.1 5.7 0.57 0.5 0.5 0.7 0.46 0.39 0.51 0.53 0.5 0.49 0.46 0.49 0.46 0.46 0.5 0.51 0.4 0.5 0.63 0.54 0.56 0.77 0.52 0.59 0.54 0.53 0.49 0.45 0.5 0.52 0.49 0.47 0.52 0.5 0.45 0.45 0.67 0.53 0.57 0.84 0.54 0.57 0.61 0.53 0.53 0.52 0.46 0.55 0.48 0.52 0.52 0.49 0.48 0.44 0.74 0.54 0.56 0.94 0.63 0.61 0.61 0.51 0.6 0.49 0.51 0.54 0.49 0.48 0.51 0.53 0.49 0.51 0.77 0.58 0.59 0.97 0.73 0.67 0.63 0.52 0.62 0.49 0.53 0.5 0.48 0.51 -1 0 6 24 48 72 21.1 19.7 19.7 24 24.3 23.8 35 40 42 37 38 34 5.5 6 6.8 8.9 9.3 7.3 0.49 0.48 0.5 0.49 0.51 0.48 0.49 0.48 0.51 0.5 0.51 0.49 0.5 0.49 0.51 0.5 0.51 0.49 0.5 0.49 0.5 0.5 0.51 0.49 -1 0 6 24 48 72 96 144 168 192 216 240 264 312 336 360 384 408 220 -0.86 1.22 -0.16 -0.18 0.5 0.55 -0.59 0.25 1.12 0.78 0.17 0.05 0.23 0.81 0.03 0.03 0.19 0.49 0.83 0.16 0.42 0.29 0.09 0.01 -77.9 111.5 -14.2 -16.3 45.7 50 -53.9 22.9 101.4 70.9 15.8 4.4 -0.78 1.12 -0.14 -0.16 0.46 0.5 -0.54 0.23 1.01 0.71 0.16 0.04 4.73 0.74 0.95 8.05 6.22 5.2 -0.25 1.69 0.34 1.31 1.12 1.21 0.34 0.47 0.67 0.23 -0.01 0.1 0.98 0.68 0.79 0.99 1 0.98 0.16 0.58 0.08 0.97 0.66 0.62 0.86 0.34 0.52 0.12 0 0.01 429.1 66.6 86.1 735.5 565 479.6 -22.9 153.1 31.6 119 102.4 110 30.4 43 60.2 20.6 -1.1 9.2 4.29 0.67 0.86 7.35 5.65 4.8 -0.23 1.53 0.32 1.19 1.02 1.1 0.3 0.43 0.6 0.21 -0.01 0.09 0.52 0.45 0.51 3.04 0.95 1.04 4.37 3.95 3.43 1.86 -0.23 2.13 0.32 0.88 0.26 0.29 0.7 0.19 0.29 0.86 0.4 0.99 0.74 0.68 0.98 0.95 0.76 0.9 0.47 0.9 0.11 0.57 0.06 0.43 0.51 0.2 0.28 0.44 0.11 275.7 86.1 94.9 399.5 358.8 316.4 168.8 -20.7 196.6 29.5 80 24.1 26.6 63.6 16.8 26.6 77.5 36.4 2.76 0.86 0.95 4 3.59 3.16 1.69 -0.21 1.97 0.29 0.8 0.24 0.27 0.64 0.17 0.27 0.77 0.36 0.5 0.49 0.5 0.5 0.51 0.5 0.24 0.17 0.02 0.06 0.11 0.23 0.94 0.57 0.1 0.93 0.95 1 21.9 16 1.7 5.4 9.7 21.2 0.22 0.16 0.02 0.05 0.1 0.21 0.49 0.49 0.47 0.53 0.53 0.51 Char Soil 96 144 168 192 216 240 264 312 336 360 384 408 23.8 22.7 21.6 22.4 23.2 22.9 23.4 22.5 22.5 22.3 22.1 21.9 29 27 27 29 33 32 30 30 30 29 28 31 4.8 3 2 4 6.5 5.4 5 4.4 4.5 4.3 4.4 5.1 0.49 0.48 0.5 0.49 0.49 0.48 0.5 0.49 0.49 0.5 0.49 0.48 0.5 0.5 0.51 0.49 0.5 0.48 0.52 0.51 0.5 0.51 0.49 0.49 0.51 0.51 0.52 0.49 0.51 0.49 0.53 0.52 0.51 0.51 0.5 0.49 0.52 0.53 0.53 0.5 0.52 0.49 0.55 0.54 0.52 0.52 0.5 0.5 0.53 0.55 0.53 0.5 0.52 0.49 0.57 0.55 0.53 0.53 0.51 0.5 0.58 1.04 0.47 0.16 0.5 0.13 1.09 0.86 0.66 0.37 0.26 0.36 1 0.99 0.98 0.93 0.97 0.98 1 0.99 1 0.98 0.96 0.97 52.1 94.2 42.6 14.2 45.7 11.4 98.9 78.5 59.9 33.8 23.5 32.8 0.52 0.94 0.43 0.14 0.46 0.11 0.99 0.78 0.6 0.34 0.23 0.33 -1 0 6 24 48 72 96 144 168 192 216 240 264 312 336 360 384 408 21.1 19.7 19.7 24 24.3 23.8 23.8 22.7 21.6 22.4 23.2 22.9 23.4 22.5 22.5 22.3 22.1 21.9 35 40 42 37 38 34 29 27 27 29 33 32 30 30 30 29 28 31 5.5 6 6.8 8.9 9.3 7.3 4.8 3 2 4 6.5 5.4 5 4.4 4.5 4.3 4.4 5.1 0.42 0.4 0.38 0.4 0.43 0.47 0.5 0.43 0.4 0.38 0.4 0.46 0.5 0.5 0.47 0.51 0.41 0.5 0.42 0.4 0.39 0.41 0.44 0.48 0.5 0.44 0.4 0.43 0.44 0.46 0.5 0.52 0.49 0.52 0.42 0.5 0.43 0.41 0.4 0.41 0.45 0.48 0.51 0.46 0.41 0.44 0.46 0.46 0.51 0.54 0.53 0.52 0.44 0.5 0.43 0.41 0.4 0.41 0.45 0.48 0.51 0.46 0.42 0.48 0.46 0.47 0.52 0.56 0.56 0.52 0.44 0.51 0.44 0.41 0.41 0.28 0.2 0.43 0.14 0.41 0.25 0.2 0.58 0.25 1.79 0.98 0.21 0.61 1.02 1.46 0.08 0.45 0.13 0.99 0.99 0.99 0.96 0.98 0.98 0.96 0.99 0.61 0.98 0.82 0.88 0.96 0.98 0.96 0.72 0.9 0.76 25.7 18.2 39.6 13 36.8 22.8 17.9 52.3 23 163 89.1 19 54.9 92.6 132.4 7.6 40.9 11.5 0.26 0.18 0.4 0.13 0.37 0.23 0.18 0.52 0.23 1.63 0.89 0.19 0.55 0.93 1.32 0.08 0.41 0.11 -1 0 6 24 48 72 96 144 168 192 216 240 264 312 336 360 384 21.1 19.7 19.7 24 24.3 23.8 23.8 22.7 21.6 22.4 23.2 22.9 23.4 22.5 22.5 22.3 22.1 35 40 42 37 38 34 29 27 27 29 33 32 30 30 30 29 28 5.5 6 6.8 8.9 9.3 7.3 4.8 3 2 4 6.5 5.4 5 4.4 4.5 4.3 4.4 0.48 0.5 0.42 0.48 0.5 0.48 0.48 0.51 0.42 0.39 0.43 0.51 0.49 0.43 0.47 0.44 0.46 0.48 0.5 0.43 0.48 0.51 0.49 0.52 0.53 0.43 0.44 0.44 0.52 0.49 0.44 0.48 0.47 0.46 0.48 0.5 0.43 0.49 0.52 0.5 0.56 0.54 0.46 0.46 0.46 0.53 0.5 0.45 0.48 0.47 0.46 0.48 0.5 0.43 0.49 0.53 0.53 0.59 0.56 0.46 0.48 0.46 0.54 0.5 0.45 0.49 0.48 0.46 0.49 0.48 0.47 0.04 0.02 0.17 0.31 0.53 0.97 2.01 1.22 0.76 1.6 0.53 0.52 0.21 0.46 0.26 0.46 0.1 0.3 0.17 0.81 0.88 0.99 0.97 0.99 0.98 0.94 0.97 0.81 0.95 0.95 0.97 0.92 0.73 0.63 3.3 1.7 15.4 27.7 48.2 87.9 181.7 110.5 68.9 145.5 48.4 46.8 19 41.4 24 42 9.3 0.03 0.02 0.15 0.28 0.48 0.88 1.82 1.11 0.69 1.46 0.48 0.47 0.19 0.41 0.24 0.42 0.09 408 21.9 31 5.1 0.45 0.46 0.47 0.48 0.48 0.4 0.89 36.6 0.37 221 0.46 0.49 0.51 0.47 0.41 0.5 0.48 0.47 0.54 0.57 0.56 0.52 0.44 0.51 0.5 0.43 0.49 0.54 0.54 0.62 0.59 0.47 0.5 0.46 Table D 3 Methane flux ug ch4 m -1 h Time 0 1 2 3 4 ppm -1 h -2 R² CH4 -1 g ha -1 hr CH4-C -1 g ha -1 hr (hr) 28 -1 2.8 2.6 2.4 2.8 3.1 4.8 0.2 158.2 1.6 1.2 Slurry 0 27.4 38.1 48.5 57.5 66.1 580.8 1.0 19050.4 190.5 142.9 6 0.4 0.8 0.9 1.0 2.8 29.6 0.7 976.8 9.8 7.3 24 2.4 2.2 2.2 1.7 2.9 2.5 0.0 82.1 0.8 0.6 48 1.1 1.2 1.6 1.3 1.3 3.0 0.2 99.1 1.0 0.7 72 2.7 1.9 2.6 2.1 2.6 0.0 0.0 0.0 0.0 0.0 96 1.7 1.6 1.6 1.2 -9.0 0.8 -297.0 -3.0 -2.2 144 2.9 2.7 1.9 2.4 -13.8 0.5 -455.7 -4.6 -3.4 168 2.0 3.2 3.0 3.9 5.0 39.5 0.9 1327.0 13.3 10.0 192 2.1 2.5 1.6 2.2 2.0 -3.0 0.1 -99.2 -1.0 -0.7 216 2.4 2.0 1.9 1.9 1.9 -6.6 0.6 -219.1 -2.2 -1.6 240 2.4 2.0 1.8 2.3 2.6 4.2 0.1 139.3 1.4 1.0 264 2.1 1.5 1.1 1.5 1.2 -10.8 0.5 -354.8 -3.5 -2.7 312 2.2 1.6 0.7 1.2 1.2 -14.7 0.5 -485.9 -4.9 -3.6 336 1.9 2.1 2.0 1.1 -15.0 0.5 -493.1 -4.9 -3.7 360 3.3 2.8 2.6 3.0 3.1 -1.2 0.0 -39.4 -0.4 -0.3 384 2.3 2.9 3.5 2.5 2.7 2.4 0.0 78.8 0.8 0.6 408 1.9 1.7 2.1 2.5 13.2 0.7 434.7 4.3 3.3 26 -1 2.1 2.1 2.8 2.3 1.6 -4.8 0.1 -158.2 -1.6 -1.2 Slurry 0 29.3 37.8 45.7 52.6 59.1 446.4 1.0 14642.0 146.4 109.8 6 2.0 3.1 2.8 4.4 3.7 28.7 0.7 949.4 9.5 7.1 24 2.7 2.0 2.5 1.9 1.8 -11.8 0.6 -390.7 -3.9 -2.9 48 2.1 1.9 2.8 4.6 4.8 48.4 0.9 1598.6 16.0 12.0 72 1.5 2.8 2.2 1.9 6.0 48.0 0.5 1610.5 16.1 12.1 96 0.7 2.4 2.4 5.5 8.3 109.6 0.9 3617.8 36.2 27.1 144 1.8 2.7 2.4 5.1 7.2 79.4 0.8 2620.4 26.2 19.7 168 0.7 2.4 3.2 4.3 5.5 68.5 1.0 2299.7 23.0 17.2 192 2.3 5.0 6.5 7.0 7.8 77.7 0.9 2569.7 25.7 19.3 216 1.8 2.9 3.2 4.0 40.4 1.0 1339.9 13.4 10.0 240 2.8 3.3 3.3 4.1 5.4 36.0 0.9 1194.1 11.9 9.0 264 2.4 3.5 3.8 4.1 4.3 26.4 0.9 867.3 8.7 6.5 312 1.6 6.5 9.0 12.7 15.3 201.6 1.0 6642.1 66.4 49.8 336 0.9 8.7 17.4 23.3 455.0 1.0 14959.3 149.6 112.2 360 0.6 3.5 9.4 12.8 16.4 245.5 1.0 8065.2 80.7 60.5 384 2.6 5.8 14.3 15.2 19.8 263.7 0.9 8659.3 86.6 64.9 408 2.5 4.6 5.3 7.5 8.4 88.6 1.0 2916.9 29.2 21.9 222 27 -1 2.3 2.5 3.2 2.7 2.0 -2.4 0.0 -79.1 -0.8 -0.6 Slurry 0 27.0 36.8 44.5 52.6 60.4 495.6 1.0 16255.8 162.6 121.9 6 1.2 1.9 2.9 4.2 4.4 52.6 1.0 1736.3 17.4 13.0 24 2.6 3.3 3.6 4.4 4.1 24.0 0.9 798.0 8.0 6.0 48 1.5 1.4 1.8 2.0 2.7 17.9 0.8 592.4 5.9 4.4 72 1.6 1.6 2.5 2.7 2.9 23.0 0.9 770.9 7.7 5.8 96 2.4 3.0 3.6 3.8 4.7 31.0 1.0 1021.8 10.2 7.7 144 1.5 1.2 3.0 4.5 6.8 84.5 0.9 2791.0 27.9 20.9 168 2.0 2.7 2.4 3.5 4.4 34.3 0.9 1152.2 11.5 8.6 192 1.7 3.3 3.9 5.5 5.7 60.1 1.0 1987.3 19.9 14.9 216 1.9 1.7 3.2 3.8 4.4 42.6 0.9 1414.1 14.1 10.6 240 2.1 3.9 4.3 5.3 4.8 41.3 0.8 1369.6 13.7 10.3 264 0.8 1.7 1.9 2.2 3.0 29.4 0.9 965.9 9.7 7.2 312 1.1 2.4 2.6 2.2 4.5 40.4 0.7 1332.4 13.3 10.0 336 1.5 1.2 0.6 0.6 4.2 -19.8 0.9 -650.9 -6.5 -4.9 360 1.9 3.5 4.9 6.5 8.2 93.6 1.0 3073.8 30.7 23.1 384 0.6 2.6 7.4 10.8 12.0 185.7 1.0 6099.1 61.0 45.7 408 6.3 13.7 18.6 23.5 26.4 300.6 1.0 9899.0 99.0 74.2 -1 2.4 1.7 1.0 1.9 2.6 3.6 0.0 118.6 1.2 0.9 0 1.7 3.1 4.8 5.0 7.6 81.2 1.0 2662.7 26.6 20.0 31 Alum 30 Alum 6 1.5 1.7 0.7 3.5 3.2 31.9 0.5 1052.5 10.5 7.9 24 2.5 1.3 2.9 2.9 3.1 16.3 0.4 539.9 5.4 4.0 48 2.6 3.1 3.6 3.7 4.5 26.8 1.0 886.8 8.9 6.7 72 2.7 2.0 3.0 3.8 3.9 24.7 0.7 826.6 8.3 6.2 96 0.6 1.1 0.6 1.2 1.8 15.0 0.6 495.0 4.9 3.7 144 1.9 2.3 2.5 4.7 5.1 52.9 0.9 1745.6 17.5 13.1 168 1.7 2.8 2.6 4.4 5.2 51.2 0.9 1717.8 17.2 12.9 192 1.5 0.9 0.9 0.5 1.0 -8.4 0.4 -277.8 -2.8 -2.1 216 2.3 2.6 4.4 7.3 9.5 115.4 0.9 3830.1 38.3 28.7 240 2.3 2.8 3.1 3.3 3.9 22.2 1.0 736.4 7.4 5.5 264 0.9 1.2 4.2 6.0 7.1 102.8 1.0 3378.6 33.8 25.3 312 1.5 5.3 11.5 14.1 15.7 223.6 1.0 7367.6 73.7 55.3 336 1.5 6.3 10.3 13.1 15.2 205.4 1.0 6751.8 67.5 50.6 360 1.3 2.3 2.6 3.6 3.0 27.9 0.8 917.7 9.2 6.9 384 1.5 2.7 4.1 5.5 6.7 78.5 1.0 2577.1 25.8 19.3 408 1.7 0.5 1.2 1.9 2.3 15.6 0.4 513.7 5.1 3.9 -1 1.3 2.7 3.2 5.1 6.3 74.9 1.0 2468.4 24.7 18.5 0 7.8 11.0 13.6 19.6 22.6 228.7 1.0 7502.1 75.0 56.3 6 0.3 0.8 2.4 2.8 3.3 47.3 0.9 1562.5 15.6 11.7 24 2.2 2.6 3.7 3.5 5.0 39.0 0.9 1295.1 13.0 9.7 48 1.3 2.0 2.6 3.1 3.7 35.3 1.0 1167.1 11.7 8.8 223 32 Alum 72 1.9 2.3 3.1 3.3 4.1 32.3 1.0 23 10.8 8.1 4.3 22.8 0.6 752.7 7.5 5.6 -4.8 0.1 -158.5 -1.6 -1.2 96 2.5 2.7 2.3 3.0 144 1.7 1.2 1.0 1.5 168 2.4 3.0 4.1 4.2 4.9 37.5 1.0 1257.7 12.6 9.4 192 2.0 2.2 2.4 2.5 2.8 11.4 1.0 377.0 3.8 2.8 216 1.8 1.9 1.8 2.0 1.5 -3.0 0.2 -99.6 -1.0 -0.7 240 1.3 5.4 6.6 6.9 7.4 82.7 0.8 2742.4 27.4 20.6 264 1.8 4.5 5.9 7.4 8.6 99.7 1.0 3275.7 32.8 24.6 312 1.6 2.0 3.3 3.9 4.3 43.8 1.0 1443.1 14.4 10.8 336 2.0 1.5 1.2 0.3 7.9 63.7 0.3 2094.8 20.9 15.7 360 1.1 3.5 6.3 8.4 10.5 141.6 1.0 4653.6 46.5 34.9 384 1.8 1.9 1.6 1.7 2.2 3.1 0.1 102.8 1.0 0.8 408 1.1 5.2 8.0 10.1 12.7 169.1 1.0 5567.9 55.7 41.8 -1 3.2 3.3 3.6 4.3 4.4 20.4 0.9 672.2 6.7 5.0 0 4.0 5.5 5.6 7.3 8.6 65.2 1.0 2139.2 21.4 16.0 0.3 3.3 3.9 3.5 62.3 0.6 2057.4 20.6 15.4 6 FeCl 1082.6 24 2.4 4.3 4.5 4.5 4.8 30.3 0.7 1006.2 10.1 7.5 48 2.1 3.0 3.1 3.2 3.8 21.0 0.9 694.7 6.9 5.2 72 2.7 4.3 5.2 5.3 6.5 51.1 0.9 1711.9 17.1 12.8 96 1.9 2.7 4.0 2.7 7.9 71.5 0.6 2358.0 23.6 17.7 144 1.3 1.7 2.2 2.5 3.1 26.4 1.0 873.3 8.7 6.5 168 0.5 1.1 2.4 3.4 4.2 58.4 1.0 1960.8 19.6 14.7 192 0.9 0.9 0.8 0.7 1.0 0.0 0.0 0.0 0.0 0.0 216 1.3 1.3 1.5 2.1 2.3 16.8 0.9 557.7 5.6 4.2 240 1.9 2.7 4.4 5.1 4.9 68.2 1.0 2261.6 22.6 17.0 264 1.8 2.3 2.0 1.9 2.7 8.4 0.4 276.0 2.8 2.1 312 1.7 2.2 3.3 4.3 4.5 47.1 1.0 1551.8 15.5 11.6 336 1.8 2.4 3.9 5.0 66.8 1.0 2197.2 22.0 16.5 360 1.1 1.8 4.5 6.1 7.2 100.0 1.0 3285.3 32.9 24.6 384 1.4 3.2 4.2 6.8 8.2 102.9 1.0 3378.0 33.8 25.3 408 2.3 2.9 3.9 4.8 7.0 51.0 1.0 1679.5 16.8 12.6 -1 1.1 1.5 1.7 1.0 -0.6 0.0 -19.9 -0.2 -0.1 0 5.1 7.8 11.2 13.9 179.1 1.0 5970.5 59.7 44.8 2 1.7 2.3 3.2 3.9 5.0 50.1 1.0 1668.7 16.7 12.5 8 2.1 6.2 2.6 2.8 3.1 -8.4 0.0 -276.0 -2.8 -2.1 24 2.0 2.7 2.3 3.2 2.8 12.6 0.5 413.5 4.1 3.1 48 2.3 2.6 1.9 2.1 3.0 5.0 0.1 163.7 1.6 1.2 96 2.0 1.3 1.0 1.1 0.5 -19.2 0.9 -631.0 -6.3 -4.7 192 1.7 2.3 2.6 1.8 3.0 0.0 100.0 1.0 0.7 216 4.4 3.8 3.0 3.6 -18.5 0.5 -612.1 -6.1 -4.6 240 1.8 2.2 2.3 1.5 -5.4 0.2 -178.3 -1.8 -1.3 1.7 224 24 FeCl 18 FeCl 312 1.9 2.0 2.3 2.4 6.6 10.8 1.0 355.7 3.6 2.7 336 1.6 0.9 0.7 0.5 360 1.8 1.8 1.6 0.8 5.6 46.4 0.3 1529.2 15.3 11.5 0.2 -25.2 0.9 -829.4 -8.3 -6.2 384 1.7 1.8 1.4 0.7 1.1 -13.8 0.7 -455.7 -4.6 -3.4 408 1.9 3.2 2.4 2.3 2.0 -4.2 0.0 -138.7 -1.4 -1.0 504 1.1 528 2.5 2.9 2.3 1.8 5.7 9.0 0.1 297.4 3.0 2.2 2.2 2.0 2.4 1.6 -9.6 0.5 -317.4 -3.2 -2.4 552 1.2 0.9 0.9 0.8 1.6 4.2 0.1 139.0 1.4 1.0 576 1.5 1.5 1.6 1.3 1.6 0.0 0.0 0.0 0.0 0.0 -1 2.5 2.4 1.5 2.4 2.1 -4.8 0.1 -159.2 -1.6 -1.2 0 3.4 6.7 9.1 11.6 14.9 167.4 1.0 5580.5 55.8 41.9 2 1.5 2.2 3.2 4.7 5.3 61.2 1.0 2039.7 20.4 15.3 8 1.3 1.2 1.9 2.4 2.3 19.2 0.8 630.8 6.3 4.7 24 1.8 1.7 2.4 2.4 2.1 7.8 0.4 256.0 2.6 1.9 48 1.3 1.5 1.4 1.3 1.8 4.8 0.4 157.8 1.6 1.2 96 1.9 0.1 0.2 0.0 0.3 -19.8 0.4 -650.8 -6.5 -4.9 192 1.5 1.1 1.7 1.8 10.4 0.5 343.0 3.4 2.6 216 3.7 3.8 3.1 3.1 1.4 -31.9 0.8 -1055.4 -10.6 -7.9 240 4.0 1.1 1.2 0.4 0.4 -46.3 0.7 -1527.7 -15.3 -11.5 312 1.1 0.4 0.4 0.6 -9.0 0.3 -296.4 -3.0 -2.2 336 1.8 1.9 2.5 2.2 5.7 48.6 0.6 1602.4 16.0 12.0 360 1.5 1.4 1.4 1.0 1.3 -4.8 0.4 -158.0 -1.6 -1.2 384 2.0 1.0 0.8 0.2 0.2 -26.4 0.9 -871.7 -8.7 -6.5 408 1.4 1.1 1.1 1.1 1.5 1.2 0.0 39.6 0.4 0.3 504 1.9 1.7 1.7 2.3 7.2 0.3 237.9 2.4 1.8 528 1.9 3.1 2.4 3.6 3.0 16.2 0.4 535.6 5.4 4.0 552 2.5 3.0 3.1 3.0 2.7 2.4 0.1 79.4 0.8 0.6 576 2.2 2.1 1.6 1.9 2.5 2.4 0.0 79.1 0.8 0.6 -1 1.6 1.6 1.0 1.0 0.7 -14.4 0.9 -477.6 -4.8 -3.6 0 3.2 5.8 8.0 10.6 12.2 136.4 1.0 4548.4 45.5 34.1 2 2.5 1.8 4.7 5.0 62.5 0.7 2083.3 20.8 15.6 8 1.7 2.3 1.6 2.1 2.0 2.4 0.0 78.8 0.8 0.6 24 1.8 2.2 1.4 1.5 1.6 -6.6 0.3 -216.6 -2.2 -1.6 48 2.2 1.6 2.0 2.1 2.2 3.0 0.1 98.6 1.0 0.7 96 2.8 1.4 0.7 -62.7 1.0 -2059.8 -20.6 -15.4 192 2.5 2.7 1.3 2.3 -10.5 0.3 -346.6 -3.5 -2.6 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1.4 0.6 1.0 1.1 0.7 336 2.2 1.2 0.5 1.2 360 1.5 1.2 1.4 1.4 384 1.2 1.6 1.6 408 1.9 1.8 1.2 1.9 -5.4 0.2 -177.9 -1.8 -1.3 -22.2 0.5 -729.8 -7.3 -5.5 1.3 -1.2 0.1 -39.4 -0.4 -0.3 1.3 0.3 -12.9 0.4 -425.2 -4.3 -3.2 1.5 1.3 -9.0 0.6 -296.4 -3.0 -2.2 227 PAC Char Char -1 0.6 3.3 4.9 5.6 6.6 86.2 0.9 2838.9 28.4 21.3 0 1.4 1.7 1.8 1.7 2.3 10.8 0.8 354.2 3.5 2.7 6 1.8 1.5 1.4 1.8 1.6 -0.6 0.0 -19.8 -0.2 -0.1 24 1.6 1.5 2.2 1.9 2.1 8.4 0.5 278.9 2.8 2.1 48 4.3 2.8 1.6 2.4 2.2 -26.3 0.5 -868.2 -8.7 -6.5 72 4.9 0.0 0.6 -127.5 0.6 -4273.6 -42.7 -32.1 96 4.3 2.4 2.6 1.8 2.2 -28.3 0.6 -932.9 -9.3 -7.0 144 0.9 1.0 0.5 0.5 0.3 -10.1 0.8 -335.0 -3.4 -2.5 168 1.8 1.1 0.9 0.5 0.9 -14.4 0.6 -483.9 -4.8 -3.6 192 1.7 1.5 1.8 0.9 1.4 216 2.1 1.5 0.4 0.8 240 1.6 0.8 0.6 0.9 264 1.8 0.2 0.4 312 1.9 2.3 336 1.9 2.3 360 1.1 384 -7.2 0.3 -238.1 -2.4 -1.8 -30.0 0.7 -995.9 -10.0 -7.5 0.6 -11.4 0.5 -378.1 -3.8 -2.8 0.0 0.3 -19.2 0.5 -630.8 -6.3 -4.7 1.7 1.8 1.8 -4.2 0.2 -138.4 -1.4 -1.0 2.1 1.5 -8.4 0.3 -276.1 -2.8 -2.1 1.6 2.5 1.6 2.2 13.2 0.4 433.7 4.3 3.3 2.2 1.4 1.4 1.5 2.1 -0.6 0.0 -19.7 -0.2 -0.1 408 1.3 1.0 1.6 1.4 1.2 1.2 0.0 39.5 0.4 0.3 -1 1.6 1.7 1.7 1.7 1.7 1.2 0.5 39.8 0.4 0.3 0 8.4 10.2 13.0 16.0 16.9 136.8 1.0 4560.4 45.6 34.2 6 2.9 3.3 4.0 5.1 5.8 45.6 1.0 1519.8 15.2 11.4 24 2.0 2.0 2.1 2.2 2.1 2.4 0.6 78.8 0.8 0.6 48 1.7 1.6 1.6 1.6 1.7 0.0 0.0 0.0 0.0 0.0 72 2.8 2.6 2.5 2.5 2.5 -9.0 0.7 -295.9 -3.0 -2.2 96 2.1 2.0 1.9 1.9 1.9 -3.0 0.8 -98.6 -1.0 -0.7 144 3.3 2.8 1.6 2.4 2.2 -14.3 0.4 -470.9 -4.7 -3.5 168 1.7 2.0 2.1 2.2 2.2 7.2 0.8 238.5 2.4 1.8 192 2.0 2.1 2.2 2.3 2.5 7.2 1.0 237.8 2.4 1.8 216 2.5 3.0 3.5 3.6 3.6 23.0 0.8 756.9 7.6 5.7 240 1.6 1.7 1.7 1.8 1.9 4.2 0.9 138.5 1.4 1.0 264 2.0 1.6 1.8 1.9 2.1 3.0 0.2 98.7 1.0 0.7 312 1.9 2.0 2.1 2.2 2.2 4.4 0.9 146.6 1.5 1.1 336 1.9 1.9 2.0 2.1 2.1 3.8 0.9 124.8 1.2 0.9 360 1.9 1.9 1.7 1.6 1.5 -6.6 0.9 -218.1 -2.2 -1.6 384 2.0 2.1 2.1 2.2 2.2 3.0 0.9 99.2 1.0 0.7 408 1.9 2.1 1.9 1.8 1.8 -3.0 0.4 -99.3 -1.0 -0.7 -1 1.6 1.8 2.2 2.0 1.9 4.8 0.3 159.2 1.6 1.2 0 4.9 5.9 8.1 9.3 11.2 96.2 1.0 3208.3 32.1 24.1 6 2.1 3.1 4.5 5.2 5.7 55.8 1.0 1859.7 18.6 13.9 24 2.1 1.1 1.6 1.7 1.9 1.2 0.0 39.4 0.4 0.3 48 1.7 1.7 1.8 1.8 1.9 3.0 0.9 98.4 1.0 0.7 228 Soil 72 1.3 1.3 1.3 1.3 1.4 1.2 0.5 39.4 0.4 0.3 96 2.0 2.1 2.2 2.2 2.3 4.2 0.9 138.0 1.4 1.0 144 2.0 2.0 2.0 2.1 2.1 1.8 0.8 59.4 0.6 0.4 168 1.8 1.7 1.6 1.6 1.5 -4.2 0.9 -139.1 -1.4 -1.0 192 1.3 1.0 0.6 1.1 0.9 -4.2 0.2 -138.7 -1.4 -1.0 216 2.2 1.2 1.4 1.2 0.9 -15.6 0.7 -513.8 -5.1 -3.9 240 2.3 2.4 2.4 2.2 2.1 -3.6 0.5 -118.7 -1.2 -0.9 264 2.0 2.0 1.7 1.6 1.5 -8.4 0.9 -276.5 -2.8 -2.1 312 2.1 2.1 2.2 2.2 2.3 3.0 0.9 99.1 1.0 0.7 336 2.4 2.5 2.2 1.8 1.7 -12.6 0.9 -416.0 -4.2 -3.1 360 2.6 2.6 2.5 2.6 2.4 -2.4 0.5 -79.3 -0.8 -0.6 384 2.1 2.1 2.0 2.1 2.2 1.2 0.2 39.7 0.4 0.3 408 1.8 1.8 1.7 1.8 1.6 -2.4 0.5 -79.4 -0.8 -0.6 -1 2.4 2.4 2.5 2.6 2.6 3.6 0.9 119.4 1.2 0.9 0 1.8 3.2 4.1 7.2 8.4 103.2 1.0 3440.3 34.4 25.8 6 2.1 2.3 2.6 2.9 3.1 15.6 1.0 519.9 5.2 3.9 24 2.2 2.3 2.3 2.1 1.9 -4.8 0.6 -157.7 -1.6 -1.2 48 2.2 2.3 2.3 2.2 2.2 -0.6 0.1 -19.7 -0.2 -0.1 72 1.2 1.2 1.2 1.3 1.2 0.6 0.1 19.7 0.2 0.1 96 1.8 1.7 1.6 1.4 1.5 -5.4 0.8 -177.5 -1.8 -1.3 144 2.0 2.1 2.1 2.2 2.0 0.6 0.0 19.8 0.2 0.1 168 2.0 2.2 2.3 2.3 2.4 5.4 0.9 178.9 1.8 1.3 192 1.6 1.3 1.2 1.4 1.7 1.8 0.1 59.4 0.6 0.4 216 1.3 1.3 1.1 1.1 1.1 -3.6 0.8 -118.6 -1.2 -0.9 240 1.9 2.0 2.3 2.1 1.8 -0.6 0.0 -19.8 -0.2 -0.1 264 2.0 2.0 2.1 2.1 2.3 4.2 0.8 138.2 1.4 1.0 312 2.1 2.2 2.4 2.4 2.5 6.0 0.9 198.1 2.0 1.5 336 2.4 2.4 2.1 2.2 2.3 -2.4 0.2 -79.2 -0.8 -0.6 360 2.0 2.0 2.0 1.9 1.8 -3.0 0.8 -99.1 -1.0 -0.7 384 2.1 2.2 2.2 2.3 2.5 5.4 0.9 178.5 1.8 1.3 408 1.8 1.8 1.9 2.1 2.1 5.4 0.9 178.7 1.8 1.3 229 Table D 4 Carbon dioxide flux ug CO2 m -1 h ppm 0 1 2 3 4 ppm h-1 -2 kg CO2-C ha -1 hr -1 R² 28 -1 889 1010 1120 1190 1280 5772 0.99 523126 1.4 Slurry 0 2950 3840 4580 5250 5840 43140 0.99 3892138 10.6 6 1330 1630 1900 2140 2360 15420 1.00 1401168 3.8 24 882 1010 1120 1230 1320 6576 1.00 600647 1.6 48 654 728 797 858 912 3876 1.00 352285 1.0 72 669 734 792 846 901 3456 1.00 318634 0.9 96 575 642 698 748 841 3828 0.99 347443 0.9 144 668 734 791 846 897 3420 1.00 310613 0.8 168 819 871 916 962 1010 2838 1.00 261977 0.7 192 756 851 913 972 1100 4854 0.98 441567 1.2 216 672 738 771 858 849 2844 0.92 259684 0.7 240 775 946 1010 1060 1120 4824 0.92 440120 1.2 264 606 678 732 780 819 3168 0.99 286284 0.8 312 795 896 986 1050 1110 4704 0.99 426297 1.2 336 942 1060 1160 1240 5964 0.99 539302 1.5 360 792 869 926 973 1010 3240 0.98 292814 0.8 384 760 867 931 993 1050 4236 0.98 382611 1.0 408 637 729 749 791 2892 0.92 261958 0.7 0 0.0 26 -1 833 956 1060 1140 1230 5868 0.99 531826 1.5 Slurry 0 2750 3490 4110 4670 5100 35280 0.99 3183000 8.7 6 1210 1460 1690 1900 2100 13320 1.00 1210347 3.3 24 846 972 1080 1180 1270 6336 1.00 578726 1.6 48 636 711 786 861 933 4464 1.00 405727 1.1 72 614 739 830 914 999 5670 0.99 522759 1.4 96 625 725 804 887 963 5028 1.00 456360 1.2 144 614 705 778 846 913 4434 1.00 402708 1.1 168 686 808 895 978 1060 5508 0.99 508445 1.4 192 850 955 1050 1120 1190 5070 0.99 461217 1.3 216 832 855 928 969 2904 0.97 265163 0.7 240 635 749 835 907 969 4956 0.99 452164 1.2 264 704 777 831 882 928 3318 0.99 299839 0.8 312 767 887 937 999 1070 4308 0.98 390409 1.1 336 1480 1380 1420 1450 -300 0.02 -27128 -0.1 360 786 896 977 1040 1100 4632 0.98 418616 1.1 384 798 895 969 1040 1090 4374 0.99 395076 1.1 408 665 731 787 835 880 3204 0.99 290219 0.8 230 0 0.0 27 -1 627 773 849 923 987 5220 0.97 473097 1.3 Slurry 0 2900 3730 4410 5010 5560 39600 0.99 3572755 9.7 6 1300 1580 1820 2040 2250 14160 1.00 1286675 3.5 24 868 987 1090 1180 1280 6102 1.00 557352 1.5 48 700 790 864 939 1000 4494 1.00 408454 1.1 72 657 771 850 927 996 5004 0.99 461356 1.3 96 579 694 779 858 932 5220 0.99 473786 1.3 144 591 732 812 893 967 5478 0.98 497526 1.4 168 654 792 866 934 998 4980 0.97 459705 1.3 192 766 852 919 978 1030 3924 0.99 356965 1.0 216 674 750 806 848 889 3168 0.98 289268 0.8 240 709 790 843 887 929 3222 0.98 293961 0.8 264 653 712 759 798 833 2676 0.99 241823 0.7 312 731 803 866 907 952 3276 0.99 296885 0.8 336 872 970 1030 1120 4824 0.99 436216 1.2 360 875 939 990 1030 1070 2886 0.99 260822 0.7 384 734 803 855 898 930 2922 0.98 263926 0.7 408 752 801 836 865 881 1932 0.97 175001 0.5 0 0.0 31 Alum 30 Alum -1 735 877 963 1050 1120 5658 0.98 512794 1.4 0 1480 2920 3920 4670 5380 57300 0.98 5169669 14.1 6 845 1000 1160 1310 1460 9240 1.00 839610 2.3 24 877 1030 1180 1320 1460 8736 1.00 797940 2.2 48 739 856 970 1070 1180 6576 1.00 597684 1.6 72 545 678 809 937 1060 7734 1.00 713055 1.9 96 569 678 791 898 1000 6492 1.00 589238 1.6 144 637 778 882 976 1070 6384 0.99 579812 1.6 168 637 750 856 966 1060 6372 1.00 588201 1.6 192 882 946 1000 1060 1120 3540 1.00 322033 0.9 216 596 669 726 785 832 3528 0.99 322140 0.9 240 770 845 912 976 1040 4026 1.00 367314 1.0 264 937 982 1030 1080 1130 2904 1.00 262427 0.7 312 727 789 913 969 1030 4716 0.98 427384 1.2 336 978 986 1010 1040 1060 1308 0.97 118277 0.3 360 716 791 845 899 948 3432 0.99 310166 0.8 384 782 867 946 1020 1090 4614 1.00 416753 1.1 408 807 876 953 1020 1040 3660 0.97 331524 0.9 0 0.0 -1 1040 1220 1370 1500 1610 8520 0.99 772182 2.1 0 2900 3890 4770 5590 6210 49920 0.99 4503837 12.3 6 960 1130 1290 1440 1580 9300 1.00 845062 2.3 24 851 991 1110 1230 1340 7302 1.00 666959 1.8 231 32 Alum 23 FeCl 48 781 874 953 1030 1110 4884 1.00 443901 1.2 72 794 906 1020 1110 1210 6216 1.00 573099 1.6 96 623 737 842 927 1000 5664 0.99 514086 1.4 144 640 881 917 1020 7056 0.89 640845 1.7 168 758 891 980 1060 1140 5598 0.99 516753 1.4 192 678 801 890 981 1050 5544 0.99 504336 1.4 216 773 739 805 859 879 1992 0.81 181888 0.5 240 725 831 904 973 1030 4512 0.99 411655 1.1 264 722 822 880 958 1020 4392 0.99 396894 1.1 312 859 952 1030 1100 1150 4380 0.99 396934 1.1 336 843 977 1088 1140 1030 3222 0.55 291353 0.8 360 741 872 965 1040 1110 5436 0.98 491277 1.3 384 779 867 928 980 1020 3570 0.98 322456 0.9 408 706 780 844 897 946 3582 0.99 324459 0.9 0 0.0 -1 843 970 1070 1150 1220 5604 0.99 507900 1.4 0 2000 2530 2990 3410 3780 26640 1.00 2403490 6.6 6 870 1010 1140 1260 1380 7620 1.00 692406 1.9 24 934 1050 1150 1260 1360 6372 1.00 582014 1.6 48 719 813 901 984 1060 5118 1.00 465169 1.3 72 804 911 1010 1110 1200 5946 1.00 548206 1.5 96 624 740 838 928 1010 5760 1.00 522799 1.4 144 651 722 864 948 1030 5904 0.99 536217 1.5 168 896 991 1080 1150 1230 4962 1.00 458044 1.2 192 841 949 1030 1100 1170 4854 0.99 441567 1.2 216 709 777 828 872 911 2994 0.99 273380 0.7 240 642 764 838 909 5250 0.98 478987 1.3 264 703 786 851 908 961 3828 0.99 345927 0.9 312 803 944 1050 1140 1210 6060 0.98 549183 1.5 336 944 1090 1190 1280 6648 0.99 601153 1.6 360 708 795 871 930 982 4098 0.99 370356 1.0 384 669 795 860 939 1000 4836 0.98 436805 1.2 408 671 763 806 846 3408 0.95 308698 0.8 0 0.0 -1 846 992 1060 1120 1160 4536 0.94 413845 1.1 0 2870 3650 4350 4970 5530 39840 1.00 3653149 10.0 2 1110 1280 1440 1590 1730 9300 1.00 852561 2.3 8 620 700 767 833 894 4086 1.00 369241 1.0 24 954 1090 1210 1330 1440 7272 1.00 656408 1.8 48 746 845 927 1000 1080 4938 1.00 446525 1.2 96 697 800 872 949 1020 4770 0.99 431228 1.2 192 960 1030 1090 1130 3420 0.99 310336 0.8 216 747 861 918 1000 4830 0.99 440025 1.2 1080 232 24 FeCl 18 FeCl 240 740 836 909 971 1020 4170 0.98 378792 1.0 312 966 1020 1070 1110 336 955 1020 1070 1120 1080 2892 1.00 262001 0.7 2100 0.76 190450 0.5 360 714 805 877 940 985 4062 0.98 367729 1.0 384 699 742 779 811 839 2094 0.99 190183 0.5 408 841 887 504 823 930 945 971 997 2376 0.97 215771 0.6 993 1050 4464 0.98 405684 1.1 528 873 909 949 985 1020 2220 1.00 201899 0.6 552 738 805 851 889 924 2736 0.98 249008 0.7 576 682 762 799 836 867 2664 0.96 241623 0.7 0 0.0 -1 647 807 862 903 965 4392 0.92 400707 1.1 0 2810 3245 4250 4870 5450 41430 0.99 3798945 10.4 2 1600 1780 1950 2100 2220 9360 0.99 858062 2.3 8 658 747 832 908 982 4854 1.00 438644 1.2 24 1290 1470 1630 1780 1930 9540 1.00 861129 2.3 48 825 941 1040 1140 1230 6054 1.00 547440 1.5 1190 7914 1.00 715459 2.0 4560 1.00 413782 1.1 96 666 809 949 1080 192 1070 1150 1220 1300 216 895 976 1040 1110 1230 4824 0.99 439478 1.2 240 776 861 955 1050 1130 5382 1.00 488887 1.3 312 902 969 1020 1070 3330 0.99 301681 0.8 336 964 1030 1090 1150 1230 3912 1.00 354781 1.0 360 822 903 974 1040 1100 4158 1.00 376419 1.0 384 588 681 749 801 837 3708 0.97 336770 0.9 408 769 817 872 915 951 2772 0.99 251733 0.7 504 866 974 1050 1130 5208 0.99 473298 1.3 528 740 819 883 954 998 3906 0.99 355232 1.0 552 713 779 827 865 897 2724 0.98 247916 0.7 576 701 746 790 827 865 2454 1.00 222576 0.6 0 0.0 -1 605 732 798 856 907 4368 0.96 398517 1.1 0 2130 2670 3160 3620 4030 28500 1.00 2613322 7.1 2 1270 1420 1560 1700 8580 1.00 786557 2.1 8 629 698 766 829 889 3906 1.00 352975 1.0 24 1060 1220 1360 1490 1620 8340 1.00 752811 2.1 48 769 864 950 1030 1010 3888 0.89 351577 1.0 96 573 694 790 886 971 5928 1.00 535917 1.5 192 961 1070 1170 1260 1340 5688 1.00 516138 1.4 216 860 953 1040 1120 1010 2802 0.58 255269 0.7 240 701 885 992 1100 1190 7158 0.98 650214 1.8 312 814 972 1040 1100 5556 0.94 503345 1.4 336 991 1060 1120 1180 3348 0.98 303632 0.8 1210 233 17 Lime 21 Lime 360 760 825 893 951 1010 3756 1.00 340027 0.9 384 904 937 962 990 1020 1710 1.00 155307 0.4 408 719 778 873 916 954 3648 0.97 331285 0.9 504 829 927 997 1060 4578 0.99 416044 1.1 528 702 792 848 903 954 3690 0.99 335588 0.9 552 705 760 816 864 909 3072 1.00 279588 0.8 576 790 816 847 876 898 1656 1.00 150198 0.4 0 0.0 -1 638 701 760 806 847 3138 0.99 286297 0.8 0 350 311 287 273 2 483 479 477 473 469 -1530 0.95 -140294 -0.4 -204 0.99 -18701 -0.1 8 419 416 413 410 407 -180 1.00 -16266 0.0 24 778 831 875 918 959 2694 1.00 243174 0.7 48 758 872 96 713 845 950 1020 1096 4944 0.99 447067 1.2 952 1050 1150 6474 1.00 585277 1.6 192 818 907 982 1050 1110 4362 0.99 395815 1.1 216 813 948 1040 1120 1190 5556 0.98 506165 1.4 240 794 843 893 941 980 2820 1.00 256161 0.7 264 807 856 897 950 1030 3240 0.98 293528 0.8 336 698 801 860 910 953 3714 0.97 336824 0.9 360 770 824 875 918 954 2772 0.99 250946 0.7 384 666 709 751 774 805 2058 0.99 186913 0.5 432 700 782 787 819 872 2286 0.92 207598 0.6 528 811 920 979 1030 4296 0.97 390416 1.1 552 786 839 880 918 944 2370 0.99 215540 0.6 576 720 781 823 863 893 2568 0.98 233718 0.6 600 709 731 752 791 807 1536 0.98 139314 0.4 0 0.0 -1 644 803 861 918 964 4530 0.92 413297 1.1 0 379 324 261 241 228 -2310 0.92 -211817 -0.6 2 437 435 425 419 410 -420 0.97 -38503 -0.1 8 392 382 374 380 361 -384 0.79 -34701 -0.1 24 767 826 892 937 976 3174 0.99 286501 0.8 48 717 826 1010 1090 1070 5820 0.88 526281 1.4 96 711 869 996 1110 1220 7554 0.99 682914 1.9 192 761 905 1010 1090 1160 5898 0.98 535194 1.5 216 848 937 989 1060 1120 4002 0.99 364592 1.0 240 790 921 1010 1090 1160 5454 0.98 495427 1.4 264 739 827 880 939 985 3624 0.99 328316 0.9 336 776 891 940 1060 1130 5262 0.99 477213 1.3 360 751 829 899 956 1010 3870 0.99 350347 1.0 384 688 757 810 852 882 2898 0.98 263204 0.7 432 794 835 878 911 944 2256 1.00 204873 0.6 234 19 Lime PAC 528 866 974 1050 1130 552 856 955 981 1030 576 821 870 915 955 600 639 675 710 742 5208 0.99 473298 1.3 1070 3018 0.95 274473 0.7 980 2418 0.99 220066 0.6 771 1986 1.00 180129 0.5 0 0.0 -1 872 953 1020 1070 1110 3558 0.98 324616 0.9 0 480 455 432 417 406 -1116 0.97 -102332 -0.3 2 443 435 424 421 414 -432 0.97 -39603 -0.1 8 374 361 351 343 337 -552 0.98 -49883 -0.1 24 713 751 787 820 847 2022 1.00 182516 0.5 48 646 700 789 862 927 4344 1.00 392811 1.1 96 525 688 793 898 995 6900 0.99 623790 1.7 192 820 931 1030 1120 1200 5694 1.00 516683 1.4 216 751 892 1060 1130 1190 6696 0.96 610022 1.7 240 860 1000 1100 1180 1260 5880 0.98 534124 1.5 264 937 1020 1090 1160 1200 3996 0.99 362017 1.0 336 798 915 1000 1080 1150 5214 0.99 472860 1.3 360 711 865 944 1020 1060 5118 0.95 463327 1.3 384 792 849 893 932 968 2610 0.99 237047 0.6 432 611 790 848 899 941 4614 0.89 419010 1.1 528 773 903 997 1070 5910 0.98 537095 1.5 552 754 860 931 987 1040 4194 0.98 381425 1.0 576 687 789 847 899 947 3780 0.97 344024 0.9 600 675 716 764 784 802 1932 0.96 175231 0.5 0 0.0 -1 3310 4150 4840 5500 6070 41220 0.99 3735836 10.2 0 833 1050 1200 1330 1460 9204 0.99 830395 2.3 6 681 765 845 917 987 4584 1.00 416534 1.1 24 1140 1310 1470 1620 1760 9300 1.00 849455 2.3 48 627 735 860 973 1080 6864 1.00 623860 1.7 72 464 586 737 868 993 8040 1.00 741267 2.0 96 781 889 982 1060 1130 5214 0.99 473242 1.3 144 760 882 982 1070 1150 5808 0.99 527498 1.4 168 802 948 1060 1160 1250 6648 0.99 613679 1.7 192 693 795 881 955 1020 4884 0.99 444296 1.2 216 767 863 937 981 1050 4104 0.98 374734 1.0 240 835 930 997 1060 1110 4080 0.99 372241 1.0 264 734 798 844 888 925 2832 0.99 255921 0.7 312 736 813 882 928 975 3558 0.99 322441 0.9 336 811 920 979 1030 4296 0.97 388471 1.1 360 836 910 961 1010 1050 3168 0.99 286307 0.8 384 821 870 915 955 980 2418 0.99 218403 0.6 408 678 738 792 839 887 3114 1.00 282067 0.8 235 0.0 PAC -1 2010 2234 3430 3820 4200 35796 0.94 3244250 8.8 0 836 962 1080 1190 1300 6936 1.00 625774 1.7 6 612 676 734 842 4488 0.98 407811 1.1 24 886 1010 1120 1220 1320 6468 1.00 590782 1.6 48 617 716 806 889 967 5238 1.00 476075 1.3 72 561 622 697 765 831 4098 1.00 377825 1.0 96 898 1100 1230 1330 1430 7764 0.97 704689 1.9 144 742 858 937 1010 1070 4848 0.98 440308 1.2 168 1150 1240 1280 1320 1360 3000 0.96 276931 0.8 192 960 1040 1060 1090 1120 2220 0.93 201953 0.6 216 758 896 974 1040 1100 4968 0.97 453625 1.2 240 942 994 1040 1080 1110 2532 0.99 231009 0.6 264 663 779 849 907 959 4320 0.97 390387 1.1 312 885 954 1000 1040 1080 2856 0.98 258823 0.7 336 829 827 997 1022 1060 3942 0.84 356460 1.0 360 982 1050 1100 1150 1190 3096 0.99 279800 0.8 384 836 874 914 953 999 2430 1.00 219487 0.6 408 708 744 783 815 851 2142 1.00 194023 0.5 0.0 Char -1 1012 1022 1038 1044 1052 612 0.97 55836 0.2 0 678 681 688 693 698 312 0.99 28609 0.1 6 552 555 562 568 573 330 0.99 30252 0.1 24 704 706 708 709 710 102 0.98 9217 0.0 48 783 789 793 803 812 432 0.97 38995 0.1 72 722 717 724 731 729 204 0.57 18447 0.1 96 691 702 704 707 708 300 0.86 27121 0.1 144 829 832 844 847 851 354 0.94 32123 0.1 168 449 452 467 473 488 594 0.96 54115 0.1 192 594 596 598 604 609 228 0.95 20711 0.1 216 560 652 655 656 661 1236 0.57 111975 0.3 240 723 726 732 738 741 288 0.98 26119 0.1 264 890 902 917 926 943 780 0.99 70613 0.2 312 882 886 892 899 903 330 0.99 29971 0.1 336 1001 1004 1012 1014 1019 276 0.97 25064 0.1 360 702 708 714 723 736 498 0.97 45258 0.1 384 722 723 723 725 729 96 0.82 8731 0.0 408 511 524 555 571 579 1098 0.96 99931 0.3 0.0 Char -1 736 754 777 823 896 2334 0.92 212944 0.6 0 1003 1021 1134 1146 1204 3162 0.93 289941 0.8 6 823 879 933 972 1011 2814 0.99 257969 0.7 24 742 890 1023 1085 6972 0.97 630042 1.7 236 48 825 922 1057 1108 1239 6084 0.99 549173 1.5 72 552 627 645 674 681 2304 0.91 208342 0.6 96 716 724 748 776 779 1224 0.95 110655 0.3 144 713 735 746 772 783 1062 0.98 96368 0.3 168 924 926 931 937 946 330 0.95 30064 0.1 192 801 810 814 823 834 474 0.98 43057 0.1 216 649 652 655 656 661 168 0.97 15220 0.0 240 702 702 705 709 710 138 0.92 12515 0.0 264 714 712 715 717 721 114 0.77 10320 0.0 312 783 786 792 793 796 198 0.96 17983 0.0 336 802 813 813 809 812 96 0.29 8718 0.0 360 853 870 876 891 902 714 0.99 64888 0.2 384 739 741 745 751 759 300 0.95 27284 0.1 408 795 801 803 809 810 228 0.96 20751 0.1 0.0 Soil -1 488 499 502 509 0 566 571 577 579 396 0.95 36129 0.1 581 228 0.95 20907 0.1 6 362 367 371 376 378 246 0.98 22552 0.1 24 466 469 478 493 505 612 0.95 55305 0.2 48 593 594 597 602 611 264 0.89 23830 0.1 72 738 741 750 757 762 384 0.98 34724 0.1 96 711 713 713 716 718 102 0.94 9221 0.0 144 892 903 926 951 973 1260 0.99 114334 0.3 168 764 777 781 789 795 444 0.97 40449 0.1 192 721 730 734 742 748 396 0.99 35972 0.1 216 692 703 717 728 751 858 0.98 77730 0.2 240 503 510 513 518 288 0.98 26119 0.1 264 901 903 908 911 210 0.98 19011 0.1 312 873 875 878 880 144 0.99 13078 0.0 336 772 784 801 819 837 990 0.99 89905 0.2 360 813 820 822 825 832 258 0.96 23447 0.1 384 845 850 852 857 859 210 0.98 19099 0.1 408 703 708 719 725 740 546 0.97 49692 0.1 237 Appendix E Photographs of slurry and amended slurry applied to plots (Chapter 6) 238 Figure E Photographs of slurry and amended slurry applied to plots (Chapter 6) Plot 2 No slurry applied Plot 3 Alum amended slurry 19th October 2010 1st October 2010 17th September 2010 Plot 1 Lime amended slurry 239 Plot 4 Slurry-control Plot 5 PAC amended slurry Appendix F Results of plot study 240 Notation used in Table F.1 Plot: plot identification number ttorun1: time from start of rain to runoff event 1 pHe1: pH of runoff water (average for each event) ttorun2: time from start of rain to runoff event 2 ttorun3: time from start of rain to runoff event 3 intensity1: average rainfall intensity during rainfall event 1 intensity2: average rainfall intensity during rainfall event 1 intensity3: average rainfall intensity during rainfall event 1 slope%: slope of plot Table F.1. Volume of runoff, concentrations of Cl (chlorine), NH4 (ammonium), NO2 (nitrite), DRP (dissolved reactive phosphorus), total dissolved phosphorus (TDP), TP (total phosphorus) and TON (total oxidized nitrogen). Plot Event Treatment Start 1 1 lime -60 1 1 lime 1 1 lime 1 1 1 1 End Volume Cl NH4 NO2 DRP TDP TP TON Vol runoff mg/l mg/l mg/l mg/l mg/L mg/L mg/l 0 97.0 53.2 0.5 0.0 0.8 1.1 1.7 4.1 0 5 140.1 72.2 1.4 0.1 2.1 3.1 5.4 4.8 5 10 197.1 81.1 2.0 0.1 3.2 4.0 6.8 4.1 lime 10 15 217.4 83.5 2.4 0.1 3.7 4.7 8.4 3.9 1 lime 15 20 98.7 85.6 2.6 0.1 3.9 5.3 9.4 4.4 1 lime 20 25 149.8 83.2 2.2 0.1 4.1 5.3 9.5 4.3 1 1 lime 25 30 287.6 82.2 3.1 0.1 4.2 5.5 9.3 4.3 1 1 lime 1 2 lime 0 51.1 48.7 0.0 0.0 0.3 0.5 1 2 lime 0 10 19.0 55.2 0.0 0.0 0.3 0.3 2.6 1 2 lime 10 20 17.2 57.0 0.1 0.0 0.2 0.3 3.0 1 2 lime 20 30 40.7 57.3 0.2 0.0 0.2 1.4 2.8 1 2 lime 1 3 lime 1 3 lime 1 3 1 3 1 3 lime 2 1 soil -19 0 2 1 soil 0 5 2 1 soil 5 2 1 soil 2 1 2 1 2 1187.6 t 3.2 127.9 t 0 150.2 45.7 0.0 0.0 0.1 0.1 0.2 4.4 0 10 200.0 43.5 0.0 0.0 0.1 0.1 0.2 4.4 lime 10 20 74.7 42.4 0.0 0.0 0.1 0.2 0.3 4.3 lime 20 30 112.2 40.8 0.0 0.0 0.1 0.2 0.3 4.1 47.4 28.8 1.2 0.0 0.0 0.0 0.1 5.0 52.9 28.5 1.0 0.0 0.0 0.0 0.1 4.5 10 36.9 26.2 1.2 0.0 0.0 0.0 0.0 4.5 10 15 42.4 26.4 1.3 0.0 0.0 0.0 0.0 4.6 soil 15 20 45.0 26.0 1.1 0.0 0.0 0.0 0.1 4.4 soil 20 25 35.5 26.4 1.0 0.0 0.0 0.0 4.5 1 soil 25 30 42.9 26.1 0.9 0.0 0.0 0.1 4.5 2 1 soil 2 2 soil 2 2 soil 2 2 soil 537.0 302.9 t 0 19.1 45.8 0.2 0.2 1.3 1.6 2.1 5.3 0 10 18.4 51.1 0.1 0.3 1.9 2.3 2.9 5.7 10 20 39.3 48.8 0.1 0.2 1.4 2.0 5.3 241 2 2 soil 20 2 2 soil 2 3 soil 2 3 soil 2 3 2 3 2 3 soil 3 1 alum -30 3 1 alum 3 1 alum 3 1 3 3 30 31.0 47.9 0.1 0.1 1.5 0.4 5.0 107.7 t 0 95.7 49.0 0.2 0.0 0.0 0.0 0.2 3.9 0 10 84.5 46.9 0.0 0.0 0.0 0.1 0.2 3.8 soil 10 20 97.2 46.1 0.0 0.0 0.0 0.1 0.1 3.8 soil 20 30 52.3 45.8 0.0 0.0 0.0 0.0 0.1 3.7 84.0 2.1 0.1 1.6 3.2 5.3 4.5 329.7 0 50.0 0 5 34.0 82.8 2.3 0.0 2.3 7.7 9.2 4.9 5 10 54.0 169.9 5.2 0.2 5.0 8.0 15.1 2.9 alum 10 15 23.0 181.2 5.8 0.1 5.1 12.6 2.8 1 alum 15 20 45.0 175.6 10.0 0.0 6.2 14.7 4.2 1 alum 20 25 32.0 174.7 7.7 0.2 5.9 15.2 3.0 3 1 alum 25 30 35.0 160.9 5.6 0.1 6.0 15.4 2.0 3 1 alum 3 2 alum 0 106.0 63.6 0.2 0.1 0.1 0.3 0.4 6.8 3 2 alum 0 10 61.8 61.0 0.2 0.0 0.1 0.3 0.4 6.6 3 2 alum 10 20 76.4 57.9 0.1 0.0 0.2 0.3 0.5 6.1 3 2 alum 20 30 66.1 58.4 0.0 0.0 0.2 0.3 0.4 5.9 3 2 alum 3 3 alum 0.2 0.2 3.0 3 3 alum 0.2 3.0 3 3 alum 3 3 alum 4 1 slurry 4 1 4 1 4 7.1 273.0 t 310.3 t 0 48.6 38.3 0.0 0.0 0.0 0 10 15.9 36.6 0.0 0.0 0.1 20 30 17.6 35.6 0.0 0.0 0.1 3.3 82.2 0 5 17.0 29.6 0.9 0.0 0.0 0.1 0.2 5.0 slurry 5 10 23.1 48.1 2.3 0.0 0.0 0.1 0.3 5.5 slurry 15 20 37.2 40.2 2.1 0.0 0.0 0.2 5.6 1 slurry 20 25 29.2 42.2 2.6 0.0 0.0 4 1 slurry 25 30 36.1 40.2 2.5 0.0 0.0 4 1 slurry 4 2 slurry 4 2 slurry 4 2 4 2 4 2 slurry 4 3 slurry 4 3 slurry 4 3 slurry 4 3 slurry 20 4 3 slurry 5 1 pac 5 1 pac 5 1 pac 2.0 5.2 0.3 5.1 0.3 4.0 142.5 t 0 104.0 32.9 0.1 0.0 0.1 0.1 0 10 67.0 29.6 0.2 0.0 0.1 0.3 3.2 slurry 10 20 66.5 30.0 0.1 0.0 0.2 0.3 3.2 slurry 20 30 59.0 30.1 0.0 0.0 0.0 0.2 3.2 296.5 t 0 58.8 36.6 0.0 0.0 0.0 0.0 0.1 3.7 0 10 43.8 36.0 0.0 0.0 0.0 0.0 0.1 3.8 10 20 37.7 35.9 0.0 0.0 0.0 0.1 3.8 30 33.8 36.2 0.0 0.0 0.0 0.1 3.9 0.2 4.7 174.1 t 0 59.1 96.2 0.7 0.0 0.0 0 5 17.9 153.2 0.9 0.1 0.0 4.8 15 20 14.8 152.0 0.7 0.1 0.0 4.7 242 5 1 pac 20 25 23.0 240.2 0.3 0.1 0.0 5 1 5 1 5 0.3 3.9 pac 5 10 12.6 159.4 0.6 0.1 0.0 4.7 pac 10 15 14.7 163.8 0.5 0.1 0.0 5.2 1 pac 25 30 6.9 326.3 1.5 0.1 0.0 4.0 5 1 pac 5 2 pac 5 2 pac 5 2 5 5 149.0 t 0 106.2 35.6 0.0 0.0 0.1 0 10 33.9 34.4 0.1 0.0 pac 10 20 70.1 34.3 0.1 2 pac 20 30 67.4 35.0 2 pac 5 3 pac 5 3 pac 5 3 pac 5 3 pac 20 5 3 pac 6 1 slurry -57 0 6 1 slurry 0 5 6 1 slurry 5 6 1 slurry 6 1 slurry 6 1 6 0.1 0.1 3.5 0.0 0.1 3.2 0.0 0.1 0.2 3.0 0.0 0.0 0.0 0.1 0.6 3.3 277.7 t 0 86.8 41.0 0.0 0.0 0.1 0.3 0.5 3.2 0 10 174.2 39.5 0.0 0.0 0.2 0.3 0.5 3.2 10 20 130.4 39.0 0.0 0.0 0.1 0.2 0.6 3.3 30 157.4 38.8 0.0 0.0 0.2 0.2 0.4 3.4 53.1 94.8 1.0 0.0 0.7 4.7 27.3 155.8 1.6 0.0 1.0 6.4 3.7 10 39.5 232.0 2.4 0.1 2.5 7.0 3.5 10 15 43.5 220.3 3.9 0.1 3.1 15 20 54.5 199.4 3.6 0.1 3.5 8.6 3.6 slurry 20 25 53.3 190.2 3.6 0.1 3.3 8.1 3.9 1 slurry 25 30 65.8 184.8 4.2 0.1 3.5 4.5 7.9 3.7 6 1 slurry 6 2 slurry 0.4 0.8 2.8 6 2 slurry 0.8 3.3 6 2 6 2 6 2 slurry 6 3 slurry 6 3 slurry 6 3 slurry 6 3 slurry 20 6 3 slurry 7 1 alum 7 1 alum 7 1 7 7 548.6 3.8 0.4 4.1 337.0 t 0 44.7 48.6 0.1 0.0 0.1 0 10 18.8 48.3 0.2 0.0 0.3 slurry 10 20 24.5 46.4 0.2 0.0 0.3 0.5 0.8 3.5 slurry 20 30 26.6 46.6 0.1 0.0 0.3 0.5 0.0 3.7 0.7 1.7 0.7 1.4 0.8 1.4 114.5 t 0 35.7 35.3 0.0 0.0 0.3 0 10 50.5 32.7 0.0 0.0 0.4 10 20 28.7 33.8 0.0 0.0 0.5 30 60.6 34.3 0.0 0.0 0.6 0.8 0.9 1.4 0.6 175.4 t 0 288.6 207.4 4.3 0.0 0.0 0.4 0.9 5.9 0 5 79.9 168.1 6.8 0.1 0.1 0.3 1.3 6.3 alum 5 10 142.1 84.8 5.5 0.1 0.1 0.3 1.0 5.7 1 alum 10 15 164.2 77.1 4.5 0.1 0.0 0.4 1.0 5.6 1 alum 15 20 165.2 65.6 4.1 0.1 0.1 0.5 0.7 5.5 7 1 alum 20 25 157.8 65.4 4.5 0.1 0.1 0.2 0.8 5.3 7 1 alum 25 30 118.1 70.8 5.7 0.1 0.1 0.2 3.0 5.2 7 1 alum 7 2 alum 7 2 alum 1115.7 t 0 0 25.2 36.5 0.0 0.0 0.0 0.6 10 28.4 46.6 1.2 0.9 1.1 2.0 243 4.6 2.3 3.2 7 2 alum 10 20 18.2 47.6 0.4 0.1 2.9 3.6 3.7 4.9 7 2 alum 20 30 52.6 48.1 0.5 0.1 2.9 3.5 3.6 4.9 7 2 alum 7 3 alum 7 3 alum 7 3 alum 7 3 alum 20 7 3 alum 8 1 soil 0 8 1 soil 0 5 8 1 soil 5 8 1 soil 8 1 soil 8 1 8 99.2 t 0 213.5 34.7 0.0 0.0 0.2 0.3 0.5 2.7 0 10 204.0 34.8 0.0 0.0 0.1 0.3 0.4 2.7 10 20 148.9 35.6 0.0 0.0 0.1 0.2 0.4 2.6 30 111.0 36.4 0.0 0.0 0.2 0.2 0.5 2.7 67.3 27.0 0.7 0.0 0.1 0.2 0.4 4.1 15.0 25.2 0.2 0.0 0.0 3.9 10 14.9 25.1 0.2 0.0 0.0 4.0 10 15 14.8 25.5 0.2 0.0 0.0 4.0 15 20 15.6 26.6 0.2 0.0 0.0 4.1 soil 20 25 15.7 25.0 0.2 0.0 0.0 3.7 1 soil 25 30 27.6 30.9 0.9 0.0 0.0 8 1 soil 25 30 27.6 42.1 0.1 0.0 0.2 8 1 soil 8 2 soil 8 2 soil 8 2 soil 8 2 soil 20 8 2 soil 8 3 soil 0 8 3 soil 0 10 8 3 soil 10 20 8 3 soil 20 30 8 3 soil 9 1 pac 9 1 pac 9 1 9 1 9 1 pac 9 2 pac 0 9 2 pac 0 10 9 2 pac 10 20 9 2 pac 20 30 9 2 pac 9 3 pac 9 3 pac 9 3 9 3 9 3 pac 10 1 lime 677.4 t 3.3 4.2 5.2 4.3 198.5 t 0 195.4 68.5 0.2 0.0 0.3 0.4 1.6 4.6 0 10 151.6 66.1 0.1 0.0 0.3 0.5 0.9 4.9 10 20 113.7 87.1 0.1 0.0 0.3 0.4 0.5 4.3 30 91.1 93.1 0.1 0.0 0.2 0.4 0.4 4.1 64.0 36.9 0.0 0.0 0.2 0.3 0.4 3.4 93.8 36.3 0.0 0.0 0.2 0.3 0.4 3.1 23.8 35.1 0.1 0.0 0.2 0.4 2.4 9.7 34.9 0.0 0.0 0.2 551.8 t 2.0 191.3 t 0 52.2 27.3 0.1 0.0 0.0 3.3 4.6 0 10 43.3 37.1 0.1 0.0 0.0 4.5 pac 10 20 163.7 42.0 0.2 0.0 0.0 5.2 pac 20 30 163.7 40.8 0.1 0.0 0.0 5.3 10.2 48.4 0.5 0.1 3.0 3.5 3.8 4.9 107.7 37.1 0.0 0.0 0.1 3.6 4.2 4.1 52.2 36.3 0.0 0.0 0.2 0.2 0.5 4.2 132.7 36.4 0.0 0.0 0.1 0.2 0.2 4.2 0.1 0.3 3.8 422.9 t 302.7 t 0 57.6 39.7 0.1 0.0 0.1 0 10 30.7 39.1 0.0 0.0 0.1 0.2 3.8 pac 10 20 17.6 40.0 0.0 0.0 0.1 0.2 3.7 pac 20 30 36.3 39.3 0.0 0.0 0.1 0.2 3.7 72.1 1.0 0.0 0.7 2.4 4.7 142.1 t 0 72.2 244 0.9 10 1 lime 0 5 33.0 92.0 0.7 0.0 1.3 10 1 10 1 10 4.0 4.6 lime 5 10 56.0 94.4 1.6 0.1 lime 10 15 53.8 94.6 1.4 0.1 2.1 8.4 4.5 2.5 10.2 4.8 1 lime 15 20 64.0 135.3 2.6 0.2 3.7 9.2 5.8 10 1 lime 20 25 78.3 87.8 10 1 lime 25 30 81.8 84.3 1.7 0.2 2.8 3.3 7.7 4.4 1.8 0.1 2.8 3.3 8.6 4.7 10 1 lime 10 2 lime 0.2 5.1 10 2 lime 10 2 lime 10 2 lime 20 10 2 lime 10 3 lime 10 3 lime 10 3 10 10 439.0 t 0 57.8 41.6 0.1 0.0 0.0 0 10 145.0 38.3 0.0 0.0 0.0 0.1 0.1 4.5 10 20 153.8 38.1 0.1 0.0 0.1 0.1 0.7 4.5 30 133.6 51.2 0.2 0.0 0.3 0.5 1.0 4.8 490.1 t 0 61.4 37.7 0.2 0.0 1.1 1.2 1.3 3.6 0 10 51.5 36.9 0.1 0.0 1.4 1.5 1.6 3.4 lime 10 20 23.0 36.6 0.1 0.0 1.2 1.4 3.1 3 lime 20 30 42.7 36.7 0.1 0.0 1.3 1.5 3.3 3 lime 11 1 pac 11 1 pac 11 1 pac 11 1 11 178.6 t 0 82.4 92.8 0.5 0.0 0.2 0.3 2.1 4.4 0 5 66.6 161.6 0.8 0.0 0.1 2.3 1.7 4.7 5 10 40.1 190.4 0.9 0.0 0.1 3.1 4.7 4.8 pac 10 15 54.8 190.5 0.8 0.0 0.1 3.0 1.3 4.7 1 pac 15 20 52.5 191.7 0.6 0.0 0.1 1.4 1.8 4.5 11 1 pac 20 25 59.3 181.2 0.2 0.0 0.0 0.9 4.4 11 1 pac 25 30 43.1 195.9 0.5 0.0 0.1 0.9 4.2 11 1 pac 11 2 pac 0 59.5 36.6 0.0 0.0 0.1 0.2 0.2 4.2 11 2 pac 0 10 93.0 38.5 0.0 0.0 0.1 0.2 0.2 3.1 11 2 pac 10 20 80.0 38.5 0.1 0.0 0.0 0.2 3.3 11 2 pac 20 30 52.0 37.2 0.0 0.0 0.0 0.2 2.9 11 2 pac 11 3 pac 11 3 pac 11 3 11 3 11 3 pac 12 2 lime 12 2 lime 12 2 lime 12 2 lime 20 12 3 lime 12 2 lime 12 3 lime 0 10 12 3 lime 10 20 398.7 t 284.5 t 0 76.5 37.1 0.0 0.0 0.1 0.2 0.2 4.3 0 10 98.5 37.3 0.0 0.0 0.1 0.2 0.2 4.3 pac 10 20 94.3 37.0 0.0 0.0 0.2 0.2 0.4 4.1 pac 20 30 62.4 34.4 0.0 0.0 0.2 0.2 0.5 4.2 331.7 t 0 50.4 39.0 0.0 0.0 0.0 0.2 3.0 0 10 24.1 36.4 0.1 0.0 0.0 0.1 4.3 10 20 22.0 36.1 0.0 0.0 0.0 0.0 4.2 30 16.9 33.4 0.0 0.0 0.0 0.3 3.7 55.5 34.9 0.0 0.0 0.0 0.2 3.4 13.4 30.1 0.0 0.0 0.1 3.1 16.1 32.5 0.0 0.0 0.1 3.2 t 0 0.2 113.4 245 12 3 lime 12 3 lime 13 1 slurry 13 1 slurry 13 1 13 1 13 20 30 9.3 33.5 0.0 0.0 0.1 3.1 38.7 t 0 35.0 147.8 1.1 0.1 2.4 0 5 34.0 162.0 1.1 0.0 slurry 5 10 43.0 141.0 1.3 slurry 10 15 39.0 133.3 0.9 1 slurry 15 20 43.0 138.1 13 1 slurry 20 25 14.8 13 1 slurry 13 2 slurry 13 2 slurry 13 2 13 2 13 2 slurry 13 3 slurry 13 3 slurry 13 3 slurry 13 3 slurry 20 13 3 slurry 14 2 alum 14 2 alum 14 2 14 14 2.6 6.3 4.0 2.8 7.0 4.1 0.0 2.7 6.8 4.5 0.0 2.4 6.1 4.4 0.8 0.1 2.0 6.4 4.2 137.5 0.8 0.0 2.1 4.3 208.8 t 0 251.7 32.1 0.0 0.0 0.0 0.1 3.7 0 10 101.4 37.1 0.0 0.0 0.3 0.6 0.7 4.0 slurry 10 20 40.2 37.2 0.0 0.0 slurry 20 30 42.2 36.9 0.0 0.0 0.3 0.5 0.6 3.5 0.3 0.5 0.7 3.7 435.5 t 0 70.4 31.5 0.1 0.0 0.7 0.8 1.0 3.9 0 10 42.8 33.3 0.0 0.0 0.6 0.8 0.9 4.0 10 20 70.3 33.5 0.0 0.0 0.6 0.7 0.9 4.1 30 44.2 34.9 0.0 0.0 0.5 0.6 0.6 4.1 227.7 t 0 114.7 37.1 0.0 0.0 0.4 0.5 0.7 3.6 0 10 60.2 44.7 0.4 0.0 0.1 0.6 0.9 4.6 alum 10 20 56.2 44.8 0.4 0.0 0.1 0.8 4.6 2 alum 20 30 42.2 44.9 0.2 0.0 0.1 0.2 0.8 4.6 2 alum 14 3 alum 43.4 29.7 0.0 0.0 0.1 0.1 0.2 2.1 14 3 alum 0 10 9.6 34.7 0.0 0.0 0.1 2.6 14 3 alum 10 20 12.6 34.5 0.0 0.0 0.1 2.3 14 3 alum 20 30 14.4 34.6 0.0 0.0 0.1 2.5 14 3 alum 15 2 alum 0 46.4 44.6 0.2 0.0 0.1 0.2 0.6 4.5 15 2 alum 0 10 18.0 37.0 0.0 0.0 0.1 0.2 0.3 4.2 15 2 alum 10 20 41.4 38.5 0.0 0.0 0.1 0.1 0.3 4.1 15 2 alum 20 30 29.3 47.8 0.2 0.0 0.3 3.2 4.4 15 2 alum 15 3 alum 0.3 4.1 15 3 alum 0.3 4.0 15 3 15 3 15 3 alum 16 1 slurry 0 16 1 slurry 5 10 16 1 slurry 15 16 1 slurry 20 273.3 t 0 80.0 t 135.1 t 0 52.1 34.6 0.0 0.0 0.1 0.1 0 10 21.6 34.7 0.0 0.0 0.1 alum 10 20 52.7 35.6 0.0 0.0 0.1 0.1 0.3 4.1 alum 20 30 45.4 36.3 0.0 0.0 0.0 0.1 0.2 4.1 87.4 55.2 0.9 0.0 0.4 5.4 30.0 70.9 0.3 0.0 1.3 4.7 20 12.3 68.4 0.6 0.0 1.4 5.0 25 18.6 68.4 0.3 0.0 1.6 4.8 171.7 t 246 16 1 slurry 10 15 18.6 68.7 0.2 0.0 1.6 16 1 slurry 16 1 slurry 0 5 30.0 62.7 0.6 0.0 0.8 25 30 19.1 66.3 0.1 0.1 1.5 4.4 16 1 slurry 0.0 0.0 16 2 slurry 0 44.0 43.5 0.0 0.0 0.1 16 2 slurry 0 10 2.5 38.1 0.0 0.0 0.1 4.5 16 2 slurry 10 20 2.6 38.1 0.0 0.0 0.1 4.4 16 2 slurry 20 30 1.9 42.3 0.0 0.0 0.0 4.5 16 2 slurry 16 3 slurry 16 3 slurry 16 3 16 3 16 3 slurry 17 1 alum 17 1 alum 17 1 alum 17 1 17 17 215.9 t 5.0 4.7 4.7 0.2 0.2 4.6 4.5 50.9 t 0 44.8 29.3 0.1 0.0 0.2 0.3 0.5 2.6 0 10 77.0 33.3 0.0 0.0 0.3 0.4 0.5 3.1 slurry 10 20 62.3 33.6 0.0 0.0 0.3 0.4 0.5 3.4 slurry 20 30 87.4 33.6 0.0 0.0 0.3 0.4 0.7 3.4 1.8 4.9 271.4 t 0 39.5 37.2 0.0 0.0 0.0 0 5 36.1 51.8 1.1 0.0 0.7 5 10 44.5 51.5 0.9 0.1 1.2 0.3 4.9 alum 10 15 51.0 52.9 0.6 0.0 0.1 0.4 5.0 1 alum 15 20 54.4 53.3 0.7 0.0 0.1 0.3 5.1 1 alum 20 25 52.9 52.5 0.5 0.0 0.0 0.3 4.9 17 1 alum 25 30 48.4 55.5 0.7 0.0 0.0 0.4 5.1 17 1 alum 17 2 alum 0 35.7 42.8 0.0 0.0 0.2 0.4 3.0 17 2 alum 0 10 13.7 39.6 0.0 0.0 0.2 3.1 17 2 alum 10 20 13.4 38.3 0.0 0.0 0.2 3.1 17 2 alum 20 30 16.5 39.2 0.0 0.0 0.2 3.0 17 2 alum 17 3 alum 17 3 alum 17 3 17 3 17 3 alum 18 1 soil 0 18 1 soil 0 5 18 1 soil 5 18 1 soil 18 1 18 1 18 0.3 5.1 326.7 t 79.3 t 0 41.3 39.3 0.3 0.0 0.1 0.2 4.2 0 10 15.4 37.7 0.2 0.0 0.1 alum 10 20 10.9 37.4 0.1 0.0 0.1 alum 20 30 42.8 30.6 0.0 0.0 0.1 0.3 0.4 1.7 105.5 59.9 1.3 0.1 0.1 0.3 1.0 5.3 19.9 49.0 1.4 0.1 0.5 4.9 10 16.2 42.4 0.5 0.0 0.0 4.5 10 15 24.2 42.2 0.5 0.1 0.1 soil 15 20 28.6 40.5 0.2 0.0 0.0 4.4 soil 20 25 34.5 40.2 0.3 0.0 0.0 4.4 1 soil 25 30 66.7 61.0 0.5 0.1 0.2 18 1 soil 25 30 31.2 40.2 0.2 0.0 0.0 4.5 18 1 soil 0 105.5 49.8 1.8 0.2 0.3 4.7 18 1 soil 15 20 24.2 40.5 0.4 0.1 0.2 4.7 18 1 soil 0 5 19.9 43.4 0.6 0.1 0.3 4.9 3.8 2.8 110.4 t t 247 0.7 0.6 0.8 4.4 5.4 18 1 soil 20 25 28.6 40.4 0.1 0.1 0.1 4.7 18 1 soil 25 30 27.8 39.1 0.3 0.1 0.2 4.7 18 1 soil 10 15 16.2 40.2 0.3 0.1 0.2 4.8 18 1 soil 18 2 soil 0 49.2 37.4 0.0 0.0 0.0 18 2 soil 0 10 6.8 37.4 0.0 0.0 0.0 3.7 18 2 soil 10 20 9.3 36.9 0.0 0.0 0.0 3.6 18 2 soil 20 30 8.7 37.2 0.0 0.0 0.1 3.5 18 2 soil 18 3 soil 18 3 soil 18 3 18 3 18 3 soil 19 1 pac 19 1 19 1 19 295.6 t 0.1 0.1 3.8 73.9 t 0 38.5 43.3 0.0 0.0 0.0 0.2 3.9 0 10 8.0 40.4 0.0 0.0 0.0 3.3 soil 10 20 14.7 39.4 0.0 0.0 0.1 2.7 soil 20 30 14.9 38.3 0.0 0.0 0.1 2.6 76.2 0 5 34.7 54.0 0.4 0.0 0.1 0.1 1.2 5.2 pac 5 10 56.9 53.6 0.2 0.1 0.0 0.2 0.6 5.1 pac 10 15 50.9 56.0 0.3 0.1 0.1 0.2 0.4 5.2 1 pac 15 20 48.9 56.6 0.4 0.1 0.2 0.2 0.5 5.1 19 1 pac 20 25 65.6 59.6 0.4 0.1 0.1 0.2 0.4 5.1 19 1 pac 25 30 54.5 63.2 0.6 0.1 0.2 0.3 0.4 5.2 19 1 pac 19 2 pac 0.3 0.4 3.6 19 2 pac 19 2 pac 19 2 pac 20 19 2 pac 19 3 pac 19 3 pac 19 3 19 19 311.5 t 0 41.2 47.8 0.0 0.0 0.2 0 10 3.1 41.0 0.0 0.0 0.2 3.8 10 20 3.8 42.6 0.0 0.0 0.2 3.7 30 11.1 41.3 0.0 0.0 0.2 3.7 59.0 t 0 54.7 40.0 0.0 0.0 0.1 0.2 0.4 3.1 0 10 48.5 37.4 0.0 0.0 0.2 0.3 0.5 2.8 pac 10 20 56.7 37.8 0.0 0.0 0.2 0.3 0.5 2.8 3 pac 20 30 39.6 37.8 0.0 0.0 0.2 0.7 2.9 3 pac 20 1 lime 9.6 2.1 20 1 lime 3.4 20 1 lime 20 1 20 199.5 t 0 59.3 129.6 3.4 0.2 5.1 0 5 49.5 150.7 3.9 0.2 6.0 10.8 5 10 80.3 0.1 15.4 lime 10 15 96.7 6.2 14.2 1 lime 15 20 110.7 2.4 12.6 20 1 lime 20 25 276.5 172.7 4.2 0.1 5.3 3.5 20 1 lime 25 30 123.0 179.4 4.1 0.1 4.7 6.4 20 1 lime 20 2 lime 0 108.5 45.4 0.0 0.0 2.8 20 2 lime 0 10 21.5 45.3 0.0 0.0 2.8 20 2 lime 10 20 19.1 45.4 0.0 0.0 2.8 4.1 20 2 lime 20 30 17.0 43.4 0.0 0.0 3.0 4.1 178.2 4.4 0.1 7.2 2.3 796.0 t 248 3.0 3.4 4.1 3.3 4.2 20 2 lime 166.0 20 3 lime 0 38.0 36.7 0.0 0.0 1.0 20 3 lime 0 10 11.9 33.7 0.0 0.0 1.6 2.9 20 3 lime 20 30 14.3 34.2 0.0 0.0 1.5 2.9 20 3 lime 21 1 alum 21 1 alum 21 1 21 21 t 1.5 3.3 64.3 t 0 47.4 48.1 0.7 0.0 0.0 0 5 52.9 58.6 0.6 0.0 alum 5 10 36.9 112.1 6.6 1 alum 10 15 42.4 133.5 1 alum 15 20 45.0 141.2 21 1 alum 20 25 35.5 21 1 alum 25 30 42.9 21 1 alum 21 2 alum 21 2 alum 21 2 21 2 21 2 alum 21 3 alum 0 21 3 alum 0 10 21 3 alum 10 21 3 alum 20 21 3 alum 22 1 soil 22 1 soil 22 1 22 1 22 1 soil 22 2 soil 22 2 soil 22 2 soil 22 2 soil 20 22 2 soil 22 3 soil 22 3 soil 22 3 22 22 0.2 0.7 5.2 0.0 0.6 5.1 0.1 0.1 1.7 6.6 11.0 0.1 0.2 3.1 7.1 12.7 0.2 0.2 3.2 7.1 138.6 12.7 0.2 0.2 2.7 6.9 127.9 14.0 0.2 0.2 2.9 7.0 0.1 4.4 302.9 t 0 44.1 43.6 0.0 0.0 0.0 0.1 0 10 7.7 43.2 0.0 0.0 0.0 4.3 alum 10 20 8.3 42.6 0.0 0.0 0.1 4.3 alum 20 30 1.0 42.0 0.0 0.0 0.1 4.4 45.7 36.6 0.0 0.0 0.1 0.3 3.8 24.3 35.8 0.0 0.0 0.1 0.1 3.6 20 29.5 36.0 0.0 0.0 0.1 0.1 3.6 30 34.4 35.8 0.0 0.0 0.0 0.1 3.8 0.2 4.5 61.2 t 0.1 133.8 t 0 46.3 48.7 1.5 0.0 0.2 0 10 3.7 40.5 0.4 0.0 0.0 4.0 soil 10 20 14.1 39.9 0.4 0.0 0.0 4.2 soil 20 30 14.5 39.1 0.3 0.0 0.0 4.1 78.6 t 0 51.1 44.7 0.0 0.0 1.0 0 10 25.3 46.6 0.2 0.0 10 20 34.0 50.9 0.0 0.0 30 66.3 51.0 0.3 2.8 3.4 4.2 0.1 0.4 3.9 0.1 0.7 3.4 0.0 0.2 0.6 3.4 176.7 t 0 221.5 38.1 0.0 0.0 0.1 0.1 0.1 3.1 0 10 211.1 37.6 0.0 0.0 0.1 0.1 0.1 3.4 soil 10 20 208.0 37.6 0.0 0.0 0.1 0.1 0.2 3.1 3 soil 20 30 230.0 37.7 0.0 0.0 0.1 0.1 0.1 3.1 3 soil 23 1 slurry 23 1 slurry 23 1 slurry 23 1 23 1 870.5 t 0 57.7 62.4 0.5 0.0 0.3 0.6 1.4 4.4 0 5 31.2 88.4 0.5 0.0 0.7 0.9 2.8 4.7 5 10 25.5 86.5 1.0 0.0 1.1 1.6 4.7 slurry 10 15 37.3 92.1 0.7 0.1 1.6 2.8 4.7 slurry 15 20 41.4 108.2 1.6 0.1 2.2 3.7 4.8 249 23 1 slurry 20 25 59.8 105.9 1.7 0.0 2.0 4.8 4.7 23 1 slurry 25 30 39.9 92.3 1.5 0.1 2.0 4.1 4.9 23 1 slurry 23 2 slurry 23 2 slurry 23 2 23 23 292.8 t 0 100.2 55.2 1.4 0.1 8.3 9.8 10.5 4.4 0 10 73.3 56.7 1.2 0.1 8.0 9.4 10.4 4.4 slurry 10 20 68.9 59.3 0.8 0.1 7.4 8.9 9.9 4.3 2 slurry 20 30 52.6 52.8 0.4 0.1 4.6 5.3 5.9 3.7 2 slurry 23 3 slurry 103.7 35.1 0.0 0.0 1.0 1.1 1.2 2.2 23 3 slurry 0 10 72.0 36.6 0.0 0.0 1.2 1.4 1.5 2.5 23 3 slurry 10 20 139.8 36.4 0.0 0.0 0.9 1.0 1.2 2.9 23 3 slurry 20 30 146.3 36.5 0.0 0.0 0.5 0.6 3.5 23 3 slurry 24 1 lime 0 50.1 50.7 0.2 0.0 0.0 0.5 4.7 24 1 lime 0 10 15.5 116.8 0.4 0.0 0.3 0.6 3.2 24 1 lime 10 20 19.4 133.4 0.5 0.0 1.2 2.2 3.7 24 1 lime 20 30 43.5 146.3 1.3 0.0 3.3 24 1 lime 24 3 lime 24 3 lime 24 3 24 3 24 3 lime 25 1 pac 0 25 1 pac 0 5 25 1 pac 5 25 1 pac 25 1 25 1 25 295.1 t 0 461.7 t 6.3 4.3 128.4 t 0 64.3 37.5 0.0 0.0 0.3 0.6 0.6 3.5 0 10 145.4 35.5 0.0 0.0 1.2 2.5 2.6 2.7 lime 10 20 220.0 35.8 0.0 0.0 1.4 2.4 2.8 2.6 lime 20 30 117.0 35.8 0.0 0.0 1.4 1.6 1.7 2.6 64.3 87.2 0.2 0.0 0.0 0.4 4.1 44.9 127.2 0.4 0.0 0.0 0.5 3.8 10 56.5 122.0 0.4 0.0 0.0 0.5 3.8 10 15 49.5 117.2 0.2 0.0 0.0 0.4 4.0 pac 15 20 57.1 118.7 0.2 0.0 0.0 0.2 0.5 4.1 pac 20 25 64.9 99.8 0.2 0.0 0.0 0.2 0.6 4.3 1 pac 25 30 68.5 97.1 0.4 0.0 0.0 0.2 0.8 4.4 25 1 pac 25 2 pac 25 2 pac 25 2 25 25 546.7 t 405.7 t 0 83.2 50.1 0.0 0.0 0.2 0.7 3.4 0 10 221.4 80.6 0.3 0.1 0.1 0.7 3.5 pac 10 20 286.7 55.8 0.1 0.0 0.1 1.3 3.6 2 pac 20 30 295.7 48.6 0.1 0.0 0.0 1.4 2.2 3.9 2 pac 25 3 pac 0.3 2.2 4.0 25 3 pac 25 3 pac 25 3 pac 20 25 3 pac 887.0 t 0 46.0 39.1 0.0 0.0 0.0 0 10 41.0 38.9 0.0 0.0 0.1 0.3 3.5 10 20 32.5 39.3 0.0 0.0 0.1 0.3 3.2 30 41.5 37.6 0.0 0.0 0.1 0.4 3.0 161 250 Table F.2 Plot physical characteristics Plot ttorun1 pH e 1 ttorun2 ttorun3 intensity1 intensity2 intensity3 slope% 1 60 7.73 50 20 14.25 9.5 8.5 5.125 2 19 6.96 70 50 13.5 9.5 8.5 3.625 3 30 8 40 25 14 10 7.8 7.25 4 35 8 114 30 14.5 10 10.5 3.75 5 40 8.2 120 40 10.5 7 9.5 3.875 6 62 7.83 57 60 14.6 10 9.25 2.375 7 60 6.97 105 40 13.01 9.5 8.9 4.125 8 72 8.8 90 35 10.98 10 10.6 4.375 9 48 8.8 62 20 13.01 9 9.25 4.5 10 35 7 111 35 10.12 8 7.98 0.375 11 74 7.4 120 50 15.01 10 8.72 0.5 12 140 7.7 75 50 12.98 9 9.5 4.875 13 130 7.8 71 30 10.5 9.5 10 1.75 14 145 7.9 115 25 13.5 9.5 9.5 3.5 15 135 7.7 54 36 12.45 11.54 9.4 0.625 16 78 7.65 121 54 11.5 9.04 8.7 0.625 17 40 8 74 34 9.5 13.12 12 3.875 18 43 7.6 90 25 9.21 8.34 10 2.875 19 45 7.5 80 50 14.25 8.35 8.76 5 20 72 7.8 75 35 10.88 8.9 10.25 4 21 47 7.66 105 42 13.23 11 10.75 3.125 22 50 7.8 95 31 8.12 11 11.22 3.75 23 120 7.8 45 25 10.5 9.75 9.23 6 24 43 7.9 32 34 10.12 8.56 8.32 4.375 25 35 7.9 25 27 12.3 8.97 9.51 4.5 251 Table F 3 Rainfall simulator allocation, blocking and treatments Application sequence plot block Sequence of rainfall simulations treat Allocation of simulators during events 1,2,3 sime1 sime2 sime3 treatment 3 1 1 5 6 2 1 2 lime 3 2 1 1 6 1 2 1 soil 3 3 1 3 7 2 1 2 alum 3 4 1 2 7 1 2 1 slurry 3 5 1 4 8 2 1 2 pac 2 6 2 2 3 2 1 2 slurry 2 7 2 3 4 1 2 1 alum 2 8 2 1 4 2 1 2 soil 2 9 2 4 5 2 1 1 pac 2 10 2 5 5 1 2 2 lime 5 11 3 4 11 1 2 2 pac 5 12 3 5 11 2 1 1 lime 5 13 3 2 12 1 2 2 slurry 5 14 3 3 12 2 1 1 alum 5 15 3 1 13 1 2 1 soil 1 16 4 2 1 2 1 1 slurry 1 17 4 3 1 1 2 2 alum 1 18 4 1 2 1 2 2 soil 1 19 4 4 2 2 1 1 pac 1 20 4 5 3 1 2 1 lime 4 21 5 3 8 1 2 1 alum 4 22 5 1 9 1 2 2 soil 4 23 5 5 9 2 1 1 lime 4 24 5 2 10 1 2 1 slurry 4 25 5 4 10 2 1 2 pac 252 Table F 4 Soil analysis results for the 25 plots potassium (K), lime requirement (LR), Mg (magnesium) and pH at times t=0 days (before slurry application) and t=30 days after the last rainfall simulation event. plot K0 LR0 Mg0 P0 pH0 K30 LR30 Mg30 P30 pH30 1 59.35 4 130.2 3.72 6.14 49.75 3 150.06 2.26 6.08 2 49.86 3.5 143.44 2.48 6.34 124.65 4 141.24 3.39 5.89 3 45.12 3.5 122.48 2.37 6.24 95.97 5 129.1 4.18 5.73 4 46.22 5.5 108.13 3.39 5.81 79.86 3.5 126.89 3.72 6.15 5 47.66 4.5 113.65 4.29 5.93 102.26 4 129.1 4.4 5.89 6 64.53 5.5 124.68 3.61 5.96 80.2 6.5 116.96 4.29 5.58 7 44.46 5 191.99 2.48 5.81 56.59 6 135.72 4.06 5.63 8 62.11 6 126.89 5.76 5.64 74.57 5 148.96 6.89 5.9 9 51.52 6 143.44 5.76 5.97 81.74 4.5 167.72 8.69 6.09 10 53.61 5.5 161.1 7.11 5.93 92.77 4.5 159.99 8.13 5.98 11 57.14 6.5 168.82 5.98 5.75 111.85 0.5 208.54 9.6 6.73 12 66.74 3 174.34 7.68 6.46 99.72 3.5 168.82 5.19 6.13 13 56.26 5 165.51 6.1 6 134.13 4 220.68 6.89 6.09 14 56.15 5.5 190.89 7.11 6 67.62 3.5 221.79 8.24 6.01 15 62.44 5 221.79 7.68 6.08 92.44 4.5 217.37 8.13 6.06 16 63.54 8 227.3 6.21 5.68 99.17 3 239.44 8.35 6.29 17 62.11 6 226.2 4.97 5.97 57.58 4.5 248.27 6.21 6.03 18 57.14 5 237.23 5.98 6.14 81.96 4 211.86 6.32 6.07 19 47.32 4.5 212.96 5.87 6.03 99.5 3.5 244.96 6.57 6.2 20 61.66 3.5 247.17 7.34 6.27 84.61 3.5 290.2 5.76 6.15 21 56.48 6.5 239.44 4.63 5.73 56.48 6 226.2 4.97 5.9 22 51.19 7 222.89 2.6 5.57 23 53.28 6 239.44 3.39 5.74 96.85 4 226.2 7.23 6.17 24 25 54.16 89.13 5 4 226.2 161.1 3.61 3.72 5.79 6.01 73.14 72.92 4.5 4 227.3 212.96 5.53 4.29 5.91 6 253 Table F 5 Slurry characterisation for plot study Plot no. WEP -1 mg kg 1 3.572 2 0.000 3 Dry matter % pH TN -1 mg L TP -1 mg L TK -1 mg L TAN -1 mg L 9.2 9.9 4359 1319 5421 1311 0.002 10.3 6.6 3881 1306 5560 1319 4 3.509 9.4 7.2 2781 1188 4875 1368 5 0.022 10.1 6.8 2155 799 3317 1284 6 3.004 9.4 7.2 4671 1280 5640 1320 7 0.005 9.8 6.3 4979 1502 6052 1343 8 0.000 9 0.003 9.5 6.8 4810 1350 5823 1307 10 1.802 9.6 6.8 5000 1478 6304 1419 11 0.004 9.7 7.7 5360 1400 5480 1320 12 3.003 9.1 7.1 5142 1417 6032 1238 13 3.169 9.2 6.7 4488 1237 4700 1225 14 0.002 9.8 6.2 4019 1061 4502 1307 16 3.567 9.5 6.2 4032 1048 4222 1364 17 0.002 9.2 7.3 4035 1066 4669 1136 18 0.000 19 0.006 9.4 6.5 3245 897 4169 1315 20 1.125 10.0 9.8 4399 1168 4227 1404 21 0.003 8.8 6.4 5118 1378 5276 690 22 0.000 23 2.909 9.3 10.3 6147 1558 6061 690 24 2.683 8.2 7.9 3830 1447 6426 743 25 0.002 8.4 6.8 4324 1051 2883 661 15 254 Table F 6 Climate data from a weather station located in Johnstown close to study site. Total Natural Mean Solar date_captured rainfall rainfall windspeed radiance humidity 01-Jul-10 12.5 12.5 9.6 1322 88.9 02-Jul-10 0 0 9.5 2660.2 83.5 03-Jul-10 0 0 7.4 2535 79.5 04-Jul-10 1.6 1.6 10.4 1892.7 79 05-Jul-10 0.4 0.4 5.1 2040.3 71.5 06-Jul-10 1 1 8.5 1133.3 84.5 07-Jul-10 2.9 2.9 10.6 2291.5 84.9 08-Jul-10 7.6 7.6 6.4 1273.8 86.1 09-Jul-10 7.5 7.5 9.5 937.8 96.1 10-Jul-10 6.7 6.7 10.2 445.7 97.9 11-Jul-10 0 0 5.6 1941 80.2 12-Jul-10 0 0 4.7 2177.6 80.2 13-Jul-10 10.8 10.8 5.6 327.1 95.1 14-Jul-10 2.7 2.7 7.6 1855 90.5 15-Jul-10 31.4 31.4 9.2 1419.3 91.8 16-Jul-10 6.9 6.9 7.1 1550.9 86.6 17-Jul-10 2.9 2.9 8.4 1969.7 81.7 18-Jul-10 18.7 18.7 12 625.8 98.2 19-Jul-10 19.5 19.5 8.1 695.1 97.8 20-Jul-10 0 0 5.5 1788.8 86.7 21-Jul-10 0.8 0.8 3.7 1750.7 86.7 22-Jul-10 7.7 7.7 5.3 1171.7 88.6 23-Jul-10 0 0 5 1924.2 81.9 24-Jul-10 1.9 1.9 6.6 678.5 98.1 25-Jul-10 0 0 4.3 1248.7 83.7 26-Jul-10 0 0 5.9 2288 84 27-Jul-10 0 0 4.8 1567.8 78.1 28-Jul-10 0 0 4.4 1158 78 29-Jul-10 0 0 4.9 1293.8 81.2 30-Jul-10 0.5 0.5 7.1 792.5 92.6 31-Jul-10 0.9 0.9 6.2 1549.2 83.9 01-Aug-10 0 0 3.8 998.1 83.5 02-Aug-10 0 0 4.3 1009.5 84.1 03-Aug-10 0.8 0.8 4.6 1669.1 80.6 04-Aug-10 0.1 0.1 6.6 1919.7 75.5 05-Aug-10 0.3 0.3 5.3 1190.9 80.2 06-Aug-10 2.3 2.3 7.4 885.2 94.9 07-Aug-10 0 0 5.1 1337.2 80.6 08-Aug-10 0 0 5.9 2099.7 73.9 09-Aug-10 0.9 0.9 7.2 2113.5 83.3 10-Aug-10 0 0 5 2144.1 68.2 11-Aug-10 0 0 4.5 1490 74.3 12-Aug-10 0 0 5.5 1051.8 72.6 13-Aug-10 0 0 7.6 2150.4 67 14-Aug-10 0 0 6.7 1910.2 75.1 15-Aug-10 0 0 5.1 1955 81.3 16-Aug-10 1.8 1.8 6.2 1071 80.2 17-Aug-10 0.2 0.2 5.7 1647 74.3 255 Atmospheric pressure 999.9 1002.9 1012 1009.7 1017.7 1016.3 1009.1 1010.1 1007.3 1005.4 1008.2 1006.9 999 988.4 989.7 999 1012.1 1012.8 1009.4 1002.6 998.2 1007.1 1015.6 1014.2 1013.4 1013.2 1012.2 1013.3 1012.8 1006.7 1006.1 1008.7 1013.4 1009.4 1004.8 1007.9 1003.7 1010.5 1014.7 1005.9 1003.8 1009.6 1014.9 1017.1 1015.9 1018.3 1013.2 1005.8 18-Aug-10 19-Aug-10 20-Aug-10 21-Aug-10 22-Aug-10 23-Aug-10 24-Aug-10 25-Aug-10 26-Aug-10 27-Aug-10 28-Aug-10 29-Aug-10 30-Aug-10 31-Aug-10 01-Sep-10 02-Sep-10 03-Sep-10 plots isolated 04-Sep-10 05-Sep-10 06-Sep-10 07-Sep-10 08-Sep-10 09-Sep-10 10-Sep-10 11-Sep-10 12-Sep-10 13-Sep-10 14-Sep-10 15-Sep-10 16-Sep-10 17-Sep-10 RS 1 18-Sep-10 19-Sep-10 20-Sep-10 21-Sep-10 22-Sep-10 23-Sep-10 24-Sep-10 25-Sep-10 26-Sep-10 RS 2 27-Sep-10 28-Sep-10 29-Sep-10 30-Sep-10 01-Oct-10 02-Oct-10 03-Oct-10 04-Oct-10 05-Oct-10 0.1 11 2.5 0.1 1.7 2.8 0 5.1 0 0 0 0 0 0 0.1 0.3 0.1 11 2.5 0.1 1.7 2.8 0 5.1 0 0 0 0 0 0 0.1 0.3 6.4 7.1 10.8 6.3 5.6 5.8 7.6 6.7 7 5.2 5.4 6.2 4 3.8 4.4 4.6 1717.4 546 1459.5 1657.3 1988.1 1855.6 1775 920 867.7 1552.6 1642.1 1306.9 1886.5 1625.8 1643.8 1667.4 80.2 94.9 94 88.1 87.4 78.4 72.7 86.9 83 70.1 71.8 68.4 73.6 81.5 85.6 82.4 1001.6 999.6 1001.8 1009.2 1005.6 995.9 1003.1 1004.4 1001.7 1009.4 1017 1015.8 1020.9 1018.3 1014.4 1013.9 0 1.8 11.5 60.5 1.3 6.5 5.5 10.4 4.3 0.7 0.3 1.8 0 0 19.42 0 0 0 0.1 3 0.7 0.1 0 17.5 0 8.2 0.1 2 7.7 8 5.2 3.6 4.6 0 1.8 11.5 60.5 1.3 6.5 5.5 10.4 4.3 0.7 0.3 1.8 0 0 0 0 0 0 0.1 3 0.7 0.1 0 0 0 8.2 0.1 2 7.7 8 5.2 3.6 4.6 4.6 6 8.6 8.1 5 4.4 7.2 10 5.8 4.8 11.8 9 7.2 3.8 5 7.2 10.3 6.9 7.4 8.9 5.8 6.7 5.7 3.1 2.5 5.4 4.4 6.5 7.9 7.3 3.8 8.2 8.7 1467.5 214.1 383.8 154.7 1365.9 1161.9 1498.7 481.2 1438.7 1168.8 609.7 1072.8 1347.8 702.2 1238.6 874.8 394.7 1108 929.7 412.1 980.6 706.9 1195.6 929.4 1224.4 425.7 1149.9 841.2 1112 581.8 1040.1 829.6 994.5 89.2 98.9 99.7 99.8 91.8 92.7 91.4 99.6 83.3 84.9 98.3 84 77.3 80.3 73.7 84.9 96 96.5 96.2 99.9 89.9 77.3 71.2 71 80.6 97.5 88.9 95 83.1 87 90.8 91.5 81.5 1013.2 1010.8 1005.5 993.2 990.8 996.3 1008.2 1005.1 1007 1019.1 1015.3 1009.3 1007.9 1009.6 1014.3 1012.9 1004.9 1005.9 1009.3 1004.3 999.3 1008.2 1015.2 1012.5 1009.3 1006.8 1007.1 1002.7 989.5 991.2 987.2 989.3 988.7 256 06-Oct-10 07-Oct-10 08-Oct-10 09-Oct-10 10-Oct-10 11-Oct-10 12-Oct-10 1.1 1 0 0 0 0.3 0.4 1.1 1 0 0 0 0.3 0.4 7.3 9.5 8.7 8.9 7.5 7 6.1 1070.3 1008.1 732.5 501.5 337.2 934.9 831.9 89.1 88.9 95.5 96.1 93.9 87.1 94.2 995.9 1005.2 1003.6 1006.1 1007.5 1013.7 1015.8 13-Oct-10 14-Oct-10 RS 3 15-Oct-10 16-Oct-10 17-Oct-10 18-Oct-10 19-Oct-10 21-Oct-10 22-Oct-10 24-Oct-10 25-Oct-10 26-Oct-10 28-Oct-10 29-Oct-10 30-Oct-10 31-Oct-10 01-Nov-10 02-Nov-10 03-Nov-10 04-Nov-10 05-Nov-10 06-Nov-10 07-Nov-10 08-Nov-10 09-Nov-10 10-Nov-10 11-Nov-10 12-Nov-10 13-Nov-10 14-Nov-10 15-Nov-10 16-Nov-10 17-Nov-10 18-Nov-10 19-Nov-10 20-Nov-10 21-Nov-10 22-Nov-10 23-Nov-10 24-Nov-10 25-Nov-10 26-Nov-10 27-Nov-10 0.3 10.45 0 0 0 0 0.5 0 7.3 0 1.1 10.8 3.5 8.8 3 17.8 3.7 2.9 4.4 0.1 2.2 1.7 16.3 5.2 3.3 1.2 9.7 0.2 2.9 0.1 2.4 12.9 20.2 0.6 6.8 0.2 3 1.7 0.5 0.4 0.4 0 9.5 0.3 0 0 0 0 0 0.5 0 7.3 0 1.1 10.8 3.5 8.8 3 17.8 3.7 2.9 4.4 0.1 2.2 1.7 16.3 5.2 3.3 1.2 9.7 0.2 2.9 0.1 2.4 12.9 20.2 0.6 6.8 0.2 3 1.7 0.5 0.4 0.4 0 9.5 4.3 5.5 6.4 5.9 4.4 5.7 5.5 4.7 7.8 6 7.7 13 11 11.7 5 7.7 7.2 11.8 7.6 14.5 3.5 5 10.2 6 10.3 6.8 14 8 5 2.9 2.7 9.4 10.4 6.9 3.8 7.3 6.7 6.5 5.9 6.1 8.5 8.1 7.9 486.2 268.8 743 727.5 840.4 491.8 620.5 813.5 362.9 861 710.3 213.9 199.8 163.3 484.1 220.6 143.5 134.5 202.7 113.6 177.5 530.6 468.5 418.8 250.1 610.5 513.1 270.3 340.3 550.1 431.5 282.1 425.8 444.5 235.4 83.9 190.7 221.9 418.8 340.1 440.7 386.3 111.3 92.6 79.7 78 81.9 81.6 85.7 85.1 76.6 90.1 76.7 75.8 98.2 95.2 94.7 91.9 93.6 95.7 91.3 95 97.6 91.6 89.9 85.6 90.6 82.8 77.2 81 84.1 89.9 88.2 93 86.7 87.5 87.7 94.9 89.6 90.4 91.8 89.2 90.4 83.6 84.9 90.4 1016.6 1017.2 1016.4 1018.2 1019.6 1014.8 1010.7 1016.3 1006.8 1013.6 1019.6 1008.2 1000.7 983.4 985.5 995.1 1005.2 999.4 1003.3 1007.4 1012.7 1011.2 998.6 960.3 977.4 993.9 977.4 985.5 984.5 990.2 1006 1006.2 988.2 992.5 1001.6 1006.8 1009.1 1007.3 1009.6 1007.6 1008.9 1003.5 1001.4 257 28-Nov-10 29-Nov-10 09-Dec-10 10-Dec-10 11-Dec-10 12-Dec-10 13-Dec-10 14-Dec-10 15-Dec-10 16-Dec-10 17-Dec-10 18-Dec-10 19-Dec-10 20-Dec-10 21-Dec-10 22-Dec-10 23-Dec-10 24-Dec-10 25-Dec-10 26-Dec-10 27-Dec-10 28-Dec-10 29-Dec-10 30-Dec-10 31-Dec-10 2.7 4.4 0 0 0 0 0.1 0 0 1 0 0 0 0 3 0.6 2 0.1 0 3.6 38.1 0.8 1.8 0.6 0 2.7 4.4 0 0 0 0 0.1 0 0 1 0 0 0 0 3 0.6 2 0.1 0 3.6 38.1 0.8 1.8 0.6 0 6 6.1 4.6 3.4 3.8 5.8 4.1 6.1 5.8 7.6 6.3 4.3 6.4 6.2 7.6 7.1 7.5 8.4 4.2 10.7 11.4 7.1 4.2 4.1 3.3 258 138.2 315.1 367 270.6 150.5 322 73.1 321.6 129.5 149.4 358.1 331.8 214.4 261.8 306.4 270 187.2 352.6 274.8 78.7 27 134.3 111.7 104.4 62.6 94.9 79.1 86.4 92.4 94.7 86 81.2 81.3 86.2 85.2 87.7 86.1 74.6 81.3 90.8 87.6 90.4 82.4 84.3 76.2 98.7 98.8 100 99.9 87.5 1000.5 1006.2 1027.6 1028.3 1022.5 1018.6 1022 1030.4 1033.3 1010.7 995.8 986.3 988.8 994 997.3 1003.5 1011 1017.9 1022.4 1014.5 999.4 1001.7 1009.8 1016.7 1020.5 Appendix G Incubation study results 259 Notation used in appendix G Soils A B C D E Treatment 1. Soil only 2. Slurry only 3. Alum 4. Lime 5. PAC 6. FeCl Cork Wexford Wexford Galway Sligo Sandy loam Clay loam Clay loam Silty loam Peat Table G. 1 Incubation study analysis results: Soil type Treatment Perecent moisture lost Month Sample 1 1 A 1 5.36 2.21 5.8 1 2 A 1 1.56 5.39 2.16 5.9 1 3 A 1 1.54 5.37 2.62 6.1 1 4 A 2 5.51 2.57 12.6 1 5 A 2 1.70 5.48 5.52 10.9 1 6 A 2 2.07 5.42 3.97 12.3 1 7 A 3 2.17 5.06 2.53 5.8 1 8 A 3 3.08 5.08 2.28 6.8 1 9 A 3 1.94 5.09 2.52 5.7 1 10 A 4 5.38 2.71 6.7 1 11 A 4 1.23 5.43 0.89 6.5 1 12 A 4 1.31 6.63 1.27 11.4 1 13 A 5 0.77 5.49 6.27 8.3 1 14 A 5 0.70 5.47 4.76 7.7 1 15 A 5 0.71 5.47 2.28 7.2 1 16 A 6 0.54 6.83 7.83 14.1 1 17 A 6 0.62 5.38 1.77 6.3 1 18 A 6 0.70 6.57 5.50 12.4 3 91 A 1 1.86 3.87 2.6 3 92 A 1 5.05 4.06 2.45 3 93 A 1 1.57 5.48 5.85 2.71 3 94 A 2 1.04 5.62 22.94 5.38 3 95 A 2 1.04 6.02 16.17 5.41 3 96 A 2 2.59 6.92 20.61 6.38 260 pH WEP Phos 3 97 A 3 0.99 3 98 A 3 7.18 5.71 5.44 3.41 3 99 A 3 6.46 5.58 4.55 4.68 3 100 A 4 2.06 6.66 5.79 5.55 3 101 A 4 1.54 7.11 8.13 3.76 3 102 A 4 0.85 5.51 8.60 7.81 3 103 A 5 2.30 6.03 9.70 2.95 3 104 A 5 1.46 5.32 9.25 5.61 3 105 A 5 1.09 5.7 7.61 8.96 3 106 A 6 2.60 5.69 2.24 8.73 3 107 A 6 0.54 7.49 3.81 13.12 3 108 A 6 1.17 5.54 0.67 8.5 6 181 A 1 5.33 5.22 3.81 6.55 6 182 A 1 4.41 5.21 3.17 6.09 6 183 A 1 13.28 5.17 3.30 5.97 6 184 A 2 4.14 5.1 8.63 12.17 6 185 A 2 0.39 5.14 8.61 12.64 6 186 A 2 0.24 5.1 8.09 11.7 6 187 A 3 2.41 4.71 3.89 6.32 6 188 A 3 3.91 4.67 4.33 7.14 6 189 A 3 4.91 4.71 3.92 6.79 6 190 A 4 4.65 4.95 3.84 7.02 6 191 A 4 3.05 4.97 4.38 6.67 6 192 A 4 4.89 4.96 3.98 6.67 6 193 A 5 0.82 4.97 5.86 8.43 6 194 A 5 2.33 4.99 7.01 8.43 6 195 A 5 1.56 4.99 5.87 8.9 6 196 A 6 3.08 6.4 10.19 25.87 6 197 A 6 8.46 6.92 10.89 22.3 6 198 A 6 5.67 4.84 3.37 16.32 9 271 A 1 5.59 5.4 2.59 6.09 9 272 A 1 5.63 5.28 2.61 6.32 9 273 A 1 3.49 5.32 4.58 6.32 9 274 A 2 3.07 5.25 4.92 12.31 9 275 A 2 3.28 5.2 6.35 12.07 9 276 A 2 6.40 5.15 6.88 12.31 9 277 A 3 3.34 4.82 3.25 8.36 9 278 A 3 4.58 4.7 3.54 8.36 9 279 A 3 2.26 4.72 3.21 8.12 9 280 A 4 5.61 4.94 3.49 7.28 9 281 A 4 -0.24 4.94 4.25 7.64 9 282 A 4 1.23 5.01 4.27 6.8 9 283 A 5 3.50 4.98 4.81 8.72 261 4.47 9 284 A 5 9.49 5.01 5.56 9 285 A 5 4.71 5.01 5.23 8.84 9 286 A 6 2.72 7.05 9.89 24.16 9 287 A 6 8.88 6.77 10.41 29.06 9 288 A 6 3.50 6.9 10.55 27.27 1 19 B 1 2.02 5.05 5.03 6.4 1 20 B 1 2.45 5.03 3.86 6.2 1 21 B 1 1.56 5.04 5.18 6.2 1 22 B 2 1.99 5.18 7.43 9 1 23 B 2 1.93 5.22 7.72 10.3 1 24 B 2 1.71 5.17 12.18 12 1 25 B 3 2.35 5.05 2.62 6.7 1 26 B 3 2.33 5.04 0.25 7.1 1 27 B 3 2.36 5.02 0.12 6.7 1 28 B 4 0.78 5.41 0.63 7 1 29 B 4 0.79 5.43 0.13 7.1 1 30 B 4 0.78 5.44 0.75 7.2 1 31 B 5 0.40 5.59 4.41 7.7 1 32 B 5 0.32 5.64 2.85 7.7 1 33 B 5 5.68 1.25 7.5 1 34 B 6 1.09 6.34 6.23 14.4 1 35 B 6 0.93 6.34 4.77 11.8 1 36 B 6 0.87 6.06 2.50 10.1 3 109 B 1 2.32 6.36 4.29 7.11 3 110 B 1 0.76 6.29 6.07 7.34 3 111 B 1 4.82 5.19 7.04 6.65 3 112 B 2 1.69 5.13 16.48 12.31 3 113 B 2 0.20 6.79 12.97 17.63 3 114 B 2 1.68 3 115 B 3 1.16 3 116 B 3 2.66 5.47 10.59 8.73 3 117 B 3 2.63 6.41 6.55 7.12 3 118 B 4 2.38 6.86 11.16 8.88 3 119 B 4 0.63 5.39 12.37 7.11 3 120 B 4 0.94 5.18 7.28 8.76 3 121 B 5 2.28 5.74 10.40 7.34 3 122 B 5 5.10 5.54 10.84 8.5 3 123 B 5 5.63 5.09 8.45 8.04 3 124 B 6 1.97 5.32 12.52 5.96 3 125 B 6 2.58 5.71 16.79 12.3 3 126 B 6 0.63 5.55 16.43 8.5 6 199 B 1 4.45 5.4 3.43 4.9 6 200 B 1 6.08 5.3 9.19 4.73 262 10.15 11.79 8.17 6 201 B 1 6 202 B 2 6.20 4.72 8.73 11.12 6 203 B 2 3.17 4.84 8.60 11.12 6 204 B 2 3.65 6 205 B 3 6.02 4.51 5.01 7.84 6 206 B 3 5.43 4.54 4.40 7.96 6 207 B 3 4.21 4.57 5.06 7.14 6 208 B 4 6.30 4.8 5.11 7.84 6 209 B 4 2.14 4.81 4.72 7.96 6 210 B 4 5.85 4.78 6 211 B 5 7.03 4.83 10.91 8.54 6 212 B 5 6.43 4.83 11.16 8.08 6 213 B 5 6 214 B 6 2.52 6.25 20.48 6 215 B 6 7.83 6.24 26.92 6 216 B 6 9 289 B 1 9 290 B 9 291 B 9 292 9 7.72 6.25 1.31 22.11 3.57 5.03 2.77 6.09 1 2.95 4.96 2.96 5.97 1 1.39 4.91 3.34 5.97 B 2 3.09 4.82 9.36 12.31 293 B 2 3.04 4.8 7.47 11.71 9 294 B 2 2.71 4.84 7.00 11.59 9 295 B 3 3.16 4.58 4.09 8.96 9 296 B 3 3.82 4.51 3.78 8.72 9 297 B 3 2.99 4.47 2.44 9.32 9 298 B 4 2.01 4.77 4.17 8 9 299 B 4 3.76 4.79 4.22 8.84 9 300 B 4 1.57 4.76 6.18 8.6 9 301 B 5 3.94 4.81 5.53 8.96 9 302 B 5 3.40 4.78 6.22 9.44 9 303 B 5 9 304 B 6 4.72 6.34 13.72 20.45 9 305 B 6 3.74 6.8 13.37 28.46 9 306 B 6 2.99 6.61 13.25 31.34 1 37 C 1 1.89 6.3 0.12 2.4 1 38 C 1 1.96 6.25 0.13 2.2 1 39 C 1 2.37 6.28 0.12 2.1 1 40 C 2 3.47 6.18 7.90 5.5 1 41 C 2 2.46 6.25 8.12 7.7 1 42 C 2 2.20 6.21 5.91 6.6 1 43 C 3 4.84 5.58 0.19 3.2 1 44 C 3 5.31 5.57 0.12 2.4 1 45 C 3 4.88 5.59 0.12 2.6 5.63 263 1 46 C 4 0.82 6.08 0.12 2.7 1 47 C 4 0.82 6.08 0.12 2.6 1 48 C 4 1.21 6.08 0.12 2.2 1 49 C 5 0.81 6.28 0.12 4.7 1 50 C 5 0.81 6.34 0.13 3 1 51 C 5 1.23 6.36 0.12 2.8 1 52 C 6 1.64 7.34 3.92 13.1 1 53 C 6 4.72 7.26 0.12 5.7 1 54 C 6 0.15 7.35 0.12 7.1 3 127 C 1 2.18 5.55 0.63 2.34 3 128 C 1 1.51 6.36 0.51 2.37 3 129 C 1 2.43 6.28 0.68 2.49 3 130 C 2 2.29 5.51 6.63 6.88 3 131 C 2 0.46 5.63 4.06 5.38 3 132 C 2 1.73 5.94 5.52 6.18 3 133 C 3 1.27 5.27 3.72 10.7 3 134 C 3 1.21 3 135 C 3 1.36 3 136 C 4 1.47 3 137 C 4 1.46 7.54 0.86 4.97 3 138 C 4 0.82 5.96 0.50 2.83 3 139 C 5 1.70 5.31 3.70 5.96 3 140 C 5 1.94 5.66 3.60 4.1 3 141 C 5 1.37 6.34 0.40 7 3 142 C 6 1.34 6.74 9.72 15.9 3 143 C 6 1.48 5.43 10.94 13.24 3 144 C 6 2.25 6 217 C 1 5.85 5.22 5.39 2.11 6 218 C 1 9.02 5.17 6.00 2.22 6 219 C 1 9.76 6.07 5.01 3.02 6 220 C 2 5.61 6.08 10.75 6.55 6 221 C 2 3.23 6.08 7.12 6.32 6 222 C 2 4.07 5.47 8.62 7.39 6 223 C 3 11.07 5.47 1.21 2.57 6 224 C 3 5.74 5.52 1.59 2.93 6 225 C 3 4.88 5.74 1.49 2.69 6 226 C 4 0.83 5.71 2.62 2.34 6 227 C 4 5.45 5.7 2.35 2.46 6 228 C 4 1.64 5.81 1.85 3.51 6 229 C 5 6.30 5.76 5.04 3.75 6 230 C 5 4.32 5.78 4.72 3.39 6 231 C 5 3.49 7.25 7.28 13.34 6 232 C 6 4.80 7.35 2.67 9.71 264 2.52 6.01 3.08 3.76 0.47 6 233 C 6 2.83 7.44 6 234 C 6 9.05 5.03 9 307 C 1 3.84 6.28 1.45 2.5 9 308 C 1 2.54 6.23 1.41 2.14 9 309 C 1 4.10 6.25 1.18 2.02 9 310 C 2 6.07 5.91 6.44 9 311 C 2 3.20 6.03 5.89 7.04 9 312 C 2 2.20 9 313 C 3 -4.44 5.4 2.78 3.69 9 314 C 3 4.06 5.46 2.27 3.57 9 315 C 3 2.63 5.41 1.52 3.57 9 316 C 4 2.50 5.6 1.46 3.33 9 317 C 4 2.59 5.61 2.07 2.85 9 318 C 4 3.53 5.65 1.18 2.61 9 319 C 5 3.29 5.68 1.19 4.41 9 320 C 5 2.30 5.72 2.14 3.81 9 321 C 5 3.60 9 322 C 6 3.48 7.28 5.60 16.02 9 323 C 6 2.04 7.43 6.04 15.54 9 324 C 6 2.18 7.28 6.21 11.83 1 55 D 1 1.98 5.33 0.24 5.2 1 56 D 1 2.07 5.3 0.14 4.5 1 57 D 1 2.19 5.34 0.28 4.5 1 58 D 2 4.08 5.6 6.07 9.6 1 59 D 2 3.16 5.56 8.16 9.4 1 60 D 2 1.48 5.51 3.85 8 1 61 D 3 4.31 5.58 0.54 5.8 1 62 D 3 4.24 5.51 0.30 5.5 1 63 D 3 3.80 5.47 0.13 5 1 64 D 4 0.75 6.12 0.23 6.1 1 65 D 4 0.80 6.07 0.14 5.6 1 66 D 4 0.95 6.11 0.14 6.2 1 67 D 5 1.24 6.34 0.32 9 1 68 D 5 1.10 6.27 0.95 7.2 1 69 D 5 1.03 6.23 0.14 7.2 1 70 D 6 1.02 6.85 4.30 16.1 1 71 D 6 1.26 6.76 0.68 11.2 1 72 D 6 0.80 6.62 3.36 10.9 3 145 D 1 2.30 5.64 5.05 5.05 3 146 D 1 1.13 5.57 4.88 4.89 3 147 D 1 2.22 3 148 D 2 0.76 3 149 D 2 1.59 265 2.34 12.99 4.56 5.38 1.83 4.34 10.58 5.72 9.91 16.81 3 150 D 2 2.82 7.22 11.25 23.01 3 151 D 3 0.51 5.52 0.60 5.61 3 152 D 3 1.43 5.5 0.56 5.61 3 153 D 3 1.09 3 154 D 4 1.16 6.87 0.55 7.82 3 155 D 4 0.44 5.68 0.55 3.64 3 156 D 4 0.74 5.71 5.89 8.73 3 157 D 5 3.43 5.72 11.37 5.96 3 158 D 5 -0.51 6.27 7.19 6.65 3 159 D 5 2.14 5.78 6.13 7.57 3 160 D 6 1.81 5.7 0.56 10.58 3 161 D 6 2.04 5.49 0.52 7.81 3 162 D 6 0.86 6.61 0.56 16.94 6 235 D 1 8.82 5.02 2.74 4.21 6 236 D 1 3.80 5.04 2.87 4.21 6 237 D 1 8.89 5.26 3.19 5.36 6 238 D 2 20.52 5.35 11.34 8.9 6 239 D 2 7.82 5.08 10.55 8.19 6 240 D 2 43.82 4.69 9.50 5.38 6 241 D 3 4.88 4.77 3.95 5.03 6 242 D 3 5.15 4.86 3.53 4.92 6 243 D 3 2.64 5.23 2.99 5.38 6 244 D 4 2.87 5.27 8.06 6 245 D 4 8.47 5.03 4.98 6 246 D 4 1.97 5.2 4.79 6.09 6 247 D 5 5.71 5.15 8.23 5.97 6 248 D 5 4.70 5.31 6.85 6.91 6 249 D 5 22.84 6.14 6 250 D 6 3.37 6.26 6.44 12.76 6 251 D 6 3.13 6.56 8.39 14.51 6 252 D 6 3.93 5.18 9 325 D 1 2.33 5.03 2.41 5.25 9 326 D 1 3.36 4.95 2.16 5.25 9 327 D 1 3.90 4.93 2.45 5.37 9 328 D 2 3.07 5.06 6.85 7.52 9 329 D 2 1.98 5.09 6.08 8.48 9 330 D 2 3.04 4.91 5.75 8.24 9 331 D 3 3.32 5.01 1.70 4.29 9 332 D 3 5.33 4.74 2.71 5.37 9 333 D 3 0.64 4.78 4.12 6.21 9 334 D 4 1.92 5.08 3.38 5.61 9 335 D 4 2.46 5.01 3.10 4.65 9 336 D 4 46.89 4.95 3.59 5.61 266 0.56 15.92 12.74 9 337 D 5 3.08 5.01 3.72 5.85 9 338 D 5 4.03 5.09 3.09 6.09 9 339 D 5 4.26 5.24 2.41 6.56 9 340 D 6 3.45 6.39 6.42 16.38 9 341 D 6 3.69 6.51 5.97 14.34 9 342 D 6 3.65 6.43 5.33 16.98 1 73 E 1 0.59 5.65 52.45 35.2 1 74 E 1 0.49 6.05 51.37 30.3 1 75 E 1 0.63 5.62 37.17 38.5 1 76 E 2 0.75 5.81 70.88 42.4 1 77 E 2 0.52 5.68 53.76 43.7 1 78 E 2 0.11 5.71 66.83 45.3 1 79 E 3 0.26 5.57 63.82 37.1 1 80 E 3 0.32 5.62 39.95 37.8 1 81 E 3 0.05 5.61 48.86 39.4 1 82 E 4 0.54 5.74 63.13 44.4 1 83 E 4 0.74 5.72 58.83 45 1 84 E 4 0.54 5.71 48.81 43.1 1 85 E 5 0.69 5.99 44.45 52.4 1 86 E 5 0.59 5.95 46.16 49.1 1 87 E 5 1.09 5.9 44.03 45.3 1 88 E 6 5.4 45 1 89 E 6 5.4 54 1 90 E 6 3 163 E 1 1.32 5.21 58.60 39.13 3 164 E 1 1.29 5.48 71.43 37.46 3 165 E 1 0.10 3 166 E 2 0.79 5.41 106.98 34.34 3 167 E 2 1.36 5.252 96.67 36.19 3 168 E 2 0.86 3 169 E 3 0.92 5.21 95.78 49.13 3 170 E 3 0.95 5.18 74.59 34.37 3 171 E 3 1.21 5.51 106.13 37 3 172 E 4 0.50 5.52 84.53 38.5 3 173 E 4 1.41 5.26 78.82 37.17 3 174 E 4 1.58 3 175 E 5 1.02 3 176 E 5 1.18 3 177 E 5 1.26 5.22 80.56 44.02 3 178 E 6 6.91 5.67 72.58 34.463 3 179 E 6 4.86 5.66 91.15 44.378 3 180 E 6 3.78 6 253 E 1 0.53 267 55.47 108.57 60.24 5.62 53.56 46.66 72.94 67.53 5.2 58.42 33.36 6 254 E 1 6.12 5.23 66.64 29.49 6 255 E 1 2.58 5.16 64.46 36.28 6 256 E 2 2.20 5.21 97.99 35.35 6 257 E 2 1.14 5.1 80.22 39.33 6 258 E 2 6.24 5.05 87.67 36.4 6 259 E 3 5.08 5.12 84.57 28.79 6 260 E 3 7.72 5.04 67.75 31.72 6 261 E 3 3.07 5.12 83.54 29.38 6 262 E 4 6.14 5.13 120.30 27.39 6 263 E 4 8.03 5.14 96.88 28.21 6 264 E 4 2.39 5.57 84.25 29.96 6 265 E 5 7.02 5.56 66.21 33.01 6 266 E 5 7.50 5.53 63.82 30.78 6 267 E 5 7.94 5.26 63.00 32 6 268 E 6 7.25 5.21 69.33 35 6 269 E 6 5.19 5.23 72.39 35 6 270 E 6 7.10 5.23 66.12 36 9 343 E 1 2.86 5.38 44.65 25.59 9 344 E 1 0.14 5.31 48.03 25.83 9 345 E 1 5.48 5.14 51.37 35.05 9 346 E 2 2.68 5.13 64.75 42.35 9 347 E 2 3.98 5.15 65.02 37.92 9 348 E 2 1.56 5.14 64.98 40.07 9 349 E 3 3.13 5.04 61.70 36.6 9 350 E 3 0.68 5.08 51.03 36.6 9 351 E 3 3.21 5.17 46.31 34.57 9 352 E 4 2.62 5.06 63.81 35.65 9 353 E 4 2.12 5.11 67.83 41.87 9 354 E 4 4.23 5.15 61.23 41.39 9 355 E 5 2.12 5.91 43.36 33.37 9 356 E 5 1.60 5.59 53.20 39.24 9 357 E 5 3.14 5.62 68.55 47.97 9 358 E 6 1.00 5.13 71.14 45.435 9 359 E 6 2.00 5.21 52.24 43.433 9 360 E 6 3.00 5.14 54.22 38.352 268
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