Controlling Nitrogen Flows and Losses

Preface 7; Section 1 - Drivers towards sustainability: why change? 27; Drivers towards sustainability: why change? 29; J.J. Neeteson, J.J. Schroder and C. Jakobsson; Nitrogen balances over seven years on a mixed farm in the Cotswolds 39; K.A. Leach, K.W.T. Goulding, D.J. Hatch, J.S. Conway and K.D. Allingham; Watershed nitrogen modelling 47; N.J. Hutchings, T. Dalgaard, B.M. Rasmussen, J.F. Hansen, M. Dahl, P. Rasmussen, L.F. Jorgensen, V. Ernstsen, F. von Platen-Hallermund and S.S. Pedersen; Mitigating non-point source pollution from dairy farms: Economic evaluation on the Don watershed 54; N. Turpin, G. Rotillon, P. Bontems, T. Bioteau and R. Laplana; Relationships between fertiliser nitrogen additions, crop carbon returns and soil quality 63; A. Bhogal, B.J. Chambers and F.A. Nicholson; Fluxes of nitrogen following clearing of Brazilian Amazonian tropical forest for pasture 65; M.C. Piccolo, C. Neill, C.C. Cerri and J.M. Melillo; Nitrogen losses from forage legumes and effects on succeeding cereal crops in organic farming under pannonic climate conditions in Eastern Austria 67; R. Farthofer, J.K. Friedel, G. Pietsch, W. Loiskandl and B. Freyer; Your farm and NVZs: A decision support system for farmers and consultants 70; C.P. Fawcett, M.M. Gibbons, F.A. Brown, P.M.R. Dampney and S.J. Richardson; Fate of applied nitrogen in a heathland ecosystem 73; E.R. Green, S.A. Power and E.M. Baggs; Effects of intensification of dairy farming in New Zealand on nitrogen efficiency, energy use and environmental emissions 76; S.F. Ledgard, J.D. Finlayson, M.S. Sprosen, D.M. Wheeler and N.A. Jollands. Effect of groundnut stover and weed management methods in the dry season on N cycling and maize yield 78; S. Promsakha na sakonnakhon, B. Toomsan, V. Limpinuntana, P. Vityakon, E.M. Baggs and G. Cadisch; Development of a decision support tool for global diffuse nitrogen pollution assessment 81; C. Macleod, J. Dela-Cruz, P. Haygarth, G. Glegg, D. Scholefield and L. Mee; Organic fertilisation in silvopastoralism and nitrate losses: sustainable systems 83; M.R. Mosquera-Losada, S. Rodriguez-Barreira and A. Rigueiro-Rodriguez; How nitrate vulnerable zones can reduce the adverse environmental impact of productive arable agriculture 85; J.U. Smith, P. Smith, A.G. Dailey and M.J. Glendining; Decline in species richness in acid grasslands along a gradient of nitrogen deposition 88; C.J. Stevens, N.B. Dise, D.J. Gowing and J.O. Mountford; Development of a modelling system for prediction and regulation of livestock waste pollution in the humid tropics 90; T.P. Tee, I.J. Lean, E.M. Baggs and G. Cadisch; The agricultural area survey as a tool for implementing the European Nitrates Directive in the Walloon Region of Belgium 93; C. Vandenberghe, A.C. Mohimont, T. Garot and J.M. Marcoen; Environmental economics of soil organic matter management 96; N. Wrage and O. Oenema; Section 2 - Matching supply with demand 99; Matching supply with demand 101; D.V. Murphy, E.A. Stockdale, F.C. Hoyle, J.U. Smith, I.R.P. Fillery, N. Milton, W.R. Cookson, L. Brussaard and D.L. Jones; Can N mineralisation be predicted from soil organic matter? Carbon and gross N mineralisation rates as affected by long-term additions of different organic amendments 113; A. Herrmann, E. Witter and T. Katterer; N mineralisation from decomposition of catch crop residues under field conditions: measurement and simulation using the STICS soil-crop model 122; E. Justes and B. Mary. Gross N transformation rates and soil organic matter contents in grassland soils of different age 131; F. Accoe, P. Boeckx, O. Van Cleemput and G. Hofman; The relative efficiency of fertiliser N in NK blends and concentrated complex fertilisers 133; N.A. Akhonzada and J.S. Bailey; Nitrogen mineralisation from fish sludge as affected by plant uptake 136; M.A. Alfaro, F.J. Salazar and A. Valdebenito; Modelling of N-cycle for processes in soil using soil core experiments 138; A. Balint, Cs. Meszaros, Gy. Heltai, E. Notas and K. Jung; Mineralisation of nitrogen in relation to climatic variation and soil 140; H. Bjornsson; Resolving differences in N cycling between more polluted and pristine forests using 15N isotope dilution 143; P. Boeckx, R. Godoy, C. Oyarzun, J. Bot and O. Van Cleemput; Effects of tillage and crop rotation on the microbial population and dynamics of soil organic matter 145; C. Carranca, A. Oliveira, A. de Varennes, M. Pampulha, M. Costa, A. Prazeres, J. Baeta, C. Neto, M.P. Andrada and M.O. Torres; The changes in microbial biomass nitrogen when different rates and forms of N were applied in a long-term experiment with maize 148; J. Cerny and J. Balik; Screening of organic biological waste products for their potential to manipulate the N release from crop residues 151; B. Chaves, S. De Neve, G. Hofman, P. Boeckx and O. Van Cleemput; Nitrogen dynamics in soil with mulch and incorporated crop residues 153; F. Coppens, S. Recous, P. Garnier and R. Merckx; Prediction of nitrogen mineralisation from organic residues and supply to ryegrass 156; C.M.d.S. Cordovil, J. Coutinho and F. Cabral; Reliability of a chemical method to assess nitrogen uptake by winter wheat 158; C.M.d.S. Cordovil, J. Coutinho and F. Cabral; Rhizodeposition and symbiotic N2 fixation in trimmed and untrimmed white clover 160; S. Dahlin. Within-field variations in, and relations between, grain protein content, grain yield and plant-available soil nitrogen 162; S. Delin; The turnover of organic manure using natural 13C abundance 164; K. Dittert and R. Bol; Nitrification during autumn and winter of ammonium nitrogen in cattle slurry applied to soil at different times during the autumn 166; L. Engstrom, B. Linden and L. Ericsson; Effect of rate of cattle slurry at sowing, number of fertigations with separated slurry liquid and rate of mineral N top dressings on yield and N removal by forage maize 168; A. Fernandes, H. Trindade, J. Coutinho and N. Moreira; N balance in fertilizer trials with composted municipal solid wastes in southern Italy 171; D. Ferri, G. Convertini and F. Montemurro; How to enhance crop utilisation of deep subsoil nitrogen supply 173; J. Haberle, P. Svoboda and J. Krejcova; Model SFOM - the first step towards fertiliser and manure use integration 176; T. Jadczyszyn; Straw-rich deep litter manures - can decomposition and N turnover be predicted from quality? 179; L.S. Jensen, A. Jensen and A. Pedersen; Field experiments to determine N accumulation under fertility building crops 182; A. Joynes, D.J. Hatch, A. Stone, S. Cuttle, G. Goodlass and S. Roderick; A comparison of different indices for nitrogen mineralisation 184; A. Kokkonen and M. Esala; A novel approach to regulate nitrogen mineralisation in soil 186; K. Kumar, C.J. Rosen and M.P. Russelle; Variable nitrogen fertilisation by tractor-mounted remote sensing 188; A. Link, J. Jasper and H.-W. Olfs; A dynamic version of the predictive balance sheet method for fertiliser N advice 191; J.M. Machet, S. Recous, M.H. Jeuffroy, B. Mary, B. Nicolardot and V. Parnaudeau. Residual effects of maize nitrogen fertilisation on winter barley crop: N content, yield, yield components and agronomic factors 194; M. Maiorana, F. Montemurro, G. Convertini and F. Fornaro; Turnover of grain legume N rhizodeposits and effect of rhizodeposition on the turnover of crop residues 197; J. Mayer, F. Buegger, E.S. Jensen, M. Schloter and J. Hess; Decomposition of soluble compounds obtained after fractionation of different animal wastes 200; T. Morvan and B. Nicolardot; Is good nutrient management possible by applying more than 170 kg nitrogen per hectare from manure? 203; A. Mulier, G. Hofman and I. Verbruggen; Regulation of N release from polyphenol-protein complexes by fungi in different tropical production systems 205; R. Mutabaruka and G. Cadisch; Modelling nitrogen mineralisation from mature bio-waste compost applied to vineyard soils 207; C. Nendel, S. Reuter, K.C. Kersebaum, R. Nieder and R. Kubiak; Inorganic N dynamics in vineyard soils under different covering strategies 209; B. Nicolardot, P. Thiebeau, C. Herre, A.F. Doledec, A. Perraud and B. Mary; Effect of rate and timing of nitrogen fertiliser on yield and grain protein content in winter wheat. The chlorophyll meter as a nutritional diagnostic tool 212; M.A. Ortuzar, A. Alonso, A. Aizpurua, A. Castellon and J.M Estavillo; Assessing N dynamics of organic wastes in field conditions using a calculation model 214; V. Parnaudeau, P. Robert, C. Herre, F. Millon, B. Mary and B. Nicolardot; 15N labelling and use of dairy manure components for N cycling studies 217; J.M. Powell and K.A. Kelling; Predicting soil mineral nitrogen in spring, based on soil mineralisable N in autumn 219; M. Quemada; Effect of seasonal split of N dosage on the fate of 15N fate in citrus trees 222; A. Quinones, J. Banuls, E. Primo-Millo and F. Legaz. Methodology of soil incubation studies -comparison between laboratories 224; T. Salo, L.S. Jensen, F. Palmason, T.A. Breland, B. Stenberg, A. Pedersen, C. Lundstrom and M. Esala; Attempts to overcome genotypic variability of SPAD readings in winter triticale 226; S. Samborski and J. Rozbicki; Organic nitrogen loads at different scale levels in Spain 229; J. Soler-Rovira and J.M. Arroyo-Sanz; Organic nutrient management indicators at district level in Spain 231; J. Soler-Rovira and J.M. Arroyo-Sanz; Physical separation of pig slurry has a small effect on the overall utilisation of nitrogen 234; P. Sorensen, I.K. Thomsen and B.T. Christensen; The use of anaerobic incubations to predict net N immobilisation after the application of organic residues to soils 236; J.R. Sousa, R. Lagoa, F. Cabral and J. Coutinho; Nitrogen uptake by ryegrass (Lolium perenne) as affected by the decomposition of apple leaves and pruning wood in soil 239; M. Tagliavini, G. Tonon, D. Solimando, P. Gioacchini, M. Toselli, P. Boldreghini and C. Ciavatta; Use of the NDICEA model analysing nitrogen efficiency 242; G.J. van der Burgt; Microbial biomass measurements in soil of the central highlands of Mexico 244; M.S. Vasquez-Murrieta and L. Dendooven; Natural 15N abundance as an indicator of the effect of management intensity on nitrogen cycling in montane grasslands 246; M. Watzka and W. Wanek; Section 3 - Controlling losses to air 249; Controlling losses to air 251; E.A. Davidson and A.R. Mosier; Pitfalls in measuring nitrous oxide production by nitrifiers 260; N. Wrage, G.L. Velthof, H.L. Laanbroek and O. Oenema. The effect of organic and mineral nitrogen fertilisers on emissions of NO, N2O and CH4 from cut grassland 268; R. Rees, S. Jones, R.E. Thorman, I. McTaggart, B. Ball and U. Skiba; A new agricultural ammonia emission inventory for Switzerland based on a large scale survey and model calculations 277; B. Reidy, S. Pfefferli and H. Menzi; N2O emissions from a field trial as influenced by N fertilisation and nitrification inhibitors 285; D. Baez, J. Coutinho, N. Moreira and H. Trindade; Denitrification and interactions between nitrification and methane oxidation under elevated atmospheric CO2 288; E.M. Baggs, H. Blum, M. Richter, G. Cadisch and U.A. Hartwig; Soil water content as a factor that controls N2O production by denitrification and autotrophic and heterotrophic nitrification 290; E.J. Bateman, G. Cadisch and E.M. Baggs; Short-term CO2 and N2O emission after application of manure and maize residues to three different soil types: a laboratory study 293; D. Beheydt, P. Boeckx, L. Geers, A. Goossens and O. Van Cleemput; Influence of urinary N concentration on N2O and CO2 emissions and N transformation in a temperate grassland soil 295; R. Bol, S.O. Petersen, K. Dittert and M.N. Hansen; A model-based evaluation of options for the mitigation of agricultural nitrous oxide emission 298; L. Brown, L. Cardenas, P. Bellamy, S.C. Jarvis, J. Hollis, R.W. Sneath, S. Yamulki and K.W.T. Goulding; Variations in aerobic respiratory and denitrifying activities in the vadose zone: laboratory and field experiments 300; P. Cannavo, F. Lafolie, A. Richaume, B. Nicolardot and P. Renault; Use of a 2-pool model to evaluate the effect of fertiliser application on nitrogen emissions from grassland soils 303; L.M. Cardenas, J.M.B. Hawkins, D. Chadwick and D. Scholefield; Opportunities for reducing ammonia emissions from pig housing in the UK 306; T.G.M. Demmers, R. Kay and N. Teer; A comparison of nitrous oxide and ammonia fluxes from managed grassland 309; C.Di Marco, M. Anderson, C. Milford, U. Skiba, M.A. Sutton and K. Weston. Gaseous losses of various nitrogeneous compounds from fertilisation of a wheat crop 311; S. Genermont, C. Henault, P. Laville, M.H. Jeuffroy and D. Flura; A simple denitrification model? Review, sensitivity and application 314; M. Heinen; Nitrous oxide emissions from soil - fertiliser and soil type effects 316; B. Hyde, A. Fanning, M. Ryan, M. Hawkins and O.T. Carton; The Irish ammonia emission inventory - implications for compliance with the Gothenburg Protocol 318; B.P. Hyde, T. Misslebrook and O.T. Carton; Greenhouse gas emissions in meadow mesocosms exposed to elevated O3 and CO2 321; T. Kanerva, K. Koivisto,K. Karhu, K. Regina and S. Manninen; Refining the uncertainty in nitrous oxide emissions from New Zealand agricultural soils 323; F.M. Kelliher, A.S. Walcroft, S.F. Ledgard, H. Clark, G. Rys, H. Plume, M. Buchan and R.R. Sherlock; Dynamics of N2O and NO production by Alcaligenes faecalis parafaecalis: effect of pH, temperature, substrate and oxygen supply 326; M. Kesik, S. Blagodatsky, H. Papen and K. Butterbach-Bahl; Denitrification and nitrate loss from organic agricultural soil at low temperatures 329; H.T. Koponen, A. Parna, H. Silvennoinen and P.J. Martikainen; N2O emissions from a water-saving rice production system (GCRPS) in North China 331; C. Kreye, K. Dittert, X. Zheng, X. Zhang, S. Lin, H. Tao and B. Sattelmacher; Controlling nitrous oxide emissions from agriculture: experience from The Netherlands 333; P.J. Kuikman, G.L. Velthof and O. Oenema; Fluxes of N2O from permanent grassland with different levels of nitrogen supply 336; C. Lampe, F. Taube, M. Wachendorf, B. Sattelmacher and K. Dittert; Gaseous nitrogen emissions from effluent irrigated soils 338; Y. Master, R.J. Stevens, R.J. Laughlin, U. Shavit and A. Shaviv; Reducing losses of nitrous oxide from cattle slurry and mineral fertiliser applied to grassland by the use of DMPP 340; P. Merino, A. del Prado, S. Menendez, L. Careaga, M. Pinto, J.M. Estavillo and C. Gonzalez-Murua. Influence of white clover on nitrous oxide fluxes in grassland 342; A. Mori, M. Hojito, H. Kondo, H. Matsunami and D. Scholefield; The effect of agricultural ammonia deposition on nitrous oxide production by soils under coniferous and deciduous woodland cover. 345; T. Morrissey, P. Ineson and D.R. Chadwick; Determination of N source in denitrification studies using stable isotope techniques 347; P.J. Murray, D.J. Hatch, E.R. Dixon, R.J. Stevens, R.J. Laughlin, K. O'Prey and S.C. Jarvis; Using a system of undisturbed, in situ soil lysimeters to determine nitrogen transformations in a sub-surface clay interface 349; P.J. Murray, E.R. Dixon, S.J. Granger, D.J. Hatch, S.C. Jarvis, R.J. Laughlin and R.J. Stevens; Urea concentration affects short-term N turnover and N2O production in grassland soil 351; S.O. Petersen, S. Stamatiadis, C. Christofides, S. Yamulki and R. Bol; Leached N and the nitrous oxide emission factor 354; D.S. Reay, K.A. Smith and A.C. Edwards; Seasonal subsoil denitrification of leached 15N-labelled nitrate 357; S.M. Thomas, T.J. Clough, G.S. Francis, D.I. Hedderley, R.R. Sherlock and M.H. Beare; N2O emissions from intensive vegetable production systems 359; S.M. Thomas, H.E. Barlow, G.S. Francis and D.I. Hedderley; Improving New Zealand predictions of N leaching for estimating indirect N2O emissions 361; S.M. Thomas, S.F. Ledgard and G.S. Francis; Nitrogen losses during storage and following the land spreading of poultry manure 363; R.E. Thorman, B.J. Chambers, R. Harrison, D.R. Chadwick, R. Matthews and R.J. Nicholson; From N2 fixation to N2O emission in a grass-clover mixture 365; M. Thyme and P. Ambus; Nitrous oxide emission from an irrigated soil fertilised with pig slurry in Central Spain 367; A. Vallejo, J.A. Diez, L. Garcia-Torres, P. Hernaiz and S. Lopez-Fernandez. Can tillage practice affect the contribution of nitrous oxide to the total greenhouse gas production from arable agriculture? 369; C.P. Webster, T.S. Scott and K.W.T. Goulding; Soils as sources of N-trace gases in Germany - results from calculations with biogeochemical models 372; C. Werner, M. Kesik, H. Papen, C. Li and K. Butterbach-Bahl; Denitrification in top soil and sub soil, data and model results 375; K.B. Zwart; Section 4 - Controlling losses to water 379; Controlling losses to water 381; M.A. Shepherd and E.I. Lord; Nitrate leaching from arable crop rotations in organic farming 389; J.E. Olesen, M. Askegaard and J. Berntsen; Nitrogen rate, surplus or residue? Performance of selected indicators for nitrate leaching 397; H.F.M. ten Berge, S.L.G.E. Burgers, M.J.D. Hack-ten Broeke, A. Smit, J.J. de Gruijter, G.L. Velthof, J.J. Schroder, J. Oenema, F.J. de Ruijter, S. Radersma, I.E. Hoving and D. Boels; Safety-nets and filter functions of tropical agroforestry systems 406; G. Cadisch, E. Rowe, D. Suprayogo and M. van Noordwijk; Comparison of the efficiency of different catch crops on potentially leachable nitrate 415; P.Y. Bontemps, R. Lambert, C. Devillers and A. Peeters; Inverse stochastic modelling of water and N drainage from lysimeters 417; M. Decrem, K.C. Abbaspour, J. Nievergelt, F. Herzog and W. Richner; Nitrogen concentrations in an intensively farmed livestock catchment 420; O. del Hierro, M. Pinto, A. Artetxe and A. del Prado; NGAUGE DSS as a tool to assist UK dairy farmers to comply with EU nitrate legislation 423; A. del Prado, L. Brown and D. Scholefield; Comparison between the risk of nitrogen leaching from temporary cut grassland and maize 425; B. Deprez, D. Knoden, H. de Blander, R. Lambert, C. Decamps and A. Peeters. Temporal and spatial denitrification patterns in nitrate retention by three riparian buffer zones 428; K. Dhondt, P. Boeckx, O. Van Cleemput and G. Hofman; Effective reductions in nitrate leaching and nitrous oxide emissions by the use of a nitrification inhibitor, dicyandiamide (DCD), in a grazed and irrigated grassland 431; H.J. Di and K.C. Cameron; Nitrate leaching and N2-fixation in grasslands of different composition, age and management 434; J. Eriksen and F.P. Vinther; Action programme and practices for reduction of nitrate from agricultural sources in Central Greece 437; T. Georgiou, T. Karyotis, I. Katsilouli, A. Haroulis, M. Toulios and G. Argyropoulos; A field study of nitrate leaching from tillage crops in Ireland 439; K.V. Hooker, K. Richards, C.E. Coxonand R. Hackett; Dissolved organic nitrogen concentration in two grassland soils 441; D.L. Jones, J.F. Farrar and V.B. Willett; Simulation with STICS soil-crop model of catch crop effects on nitrate leaching during the fallow period and on N released for the succeeding main crop 444; E. Justes, F. Dorsainvil, M. Alexandre and P. Thiebeau; Nitrate in soils and water originated from agricultural sources: a case study in Thessaly, Central Greece 447; Ir. Katsilouli, Th. Karyotis, Th. Georgiou, Th. Mitsimponas, A. Panagopoulos, A. Panoras, D. Pateras, A. Haroulis, G. Argyropoulos and M. Toulios; Monitoring and mathematical modelling of nitrate leaching in an experimental field treated with pig slurry 449; P. Mantovi, L. Fumagalli and G.P. Beretta; Nitrate leaching in arable cropland: effects of N-management 452; A. Smit and K.B. Zwart; Reducing nitrate contamination of groundwater from intensive greenhouse-based vegetable production in Almeria, Spain - management considerations 454; R.B. Thompson, M. Gallardo and C. Gimenez; Nitrogen budgets at field, farm and polder scales in a polder used for dairy farming 457; C.L. van Beek, G.L. Velthof and O. Oenema. Nitrate leaching on loess soils as affected by N fertilisation and crop rotation 459; W. van Dijk, P. Dekker and J.R. van der Schoot; Loss of inorganic nitrogen in surface runoff from grazed grassland 461; C.J. Watson, R.V. Smith and E. Chisholm; Nitrogen losses in drainage water following pig slurry applications to an arable clay soil 463; J.R. Williams, B.J. Chambers R.B. Cross and R.A. Hodgkinson; Section 5 - Reconciling productivity with environmental considerations 467; Reconciling productivity with environmental considerations 469; D. Scholefield; Forage maize production as affected by tillage, N source and nitrification inhibitors 484; D. Baez, J. Coutinho, N. Moreira and H. Trindade; Is the N balance a good indicator of nitrogen losses in arable systems? 487; N. Beaudoin, B. Mary, F. Laurent, G. Aubrion and J.K. Saad; A low disturbance technique for applying slurry on forage land 490; S. Bittman, L.J.P. van Vliet, C.G. Kowalenko, S. McGinn, A.K. Lau, N. Patni, T. Forge, N. McLaughlin, D.E. Hunt, F. Bounaix and A. Friesen; Effects of field history on the establishment of white clover in association with perennial ryegrass 493; L.M. Bommele, D. Reheul, N. Van Eekeren and F. Nevens; Nitrogen losses in relation to rice varieties, growth stages, and nitrogen forms determined with the 15N technique 496; N.C. Chen and S. Inanaga; Effectiveness of alternative managements to reduce N losses from dairy farms 498; S.P. Cuttle and M.M. Turner; Azofert: a new decision support tool for fertiliser N recommendations 500; P. Dubrulle, J.M. Machet and N. Damay; Compost use in vegetable production: impact on gross N fluxes and implications for sustainable management practices 502; T.C. Flavel and D.V. Murphy. Ammonia volatilisation and soil nitrogen dynamics following application of pig deep-litter and pig slurry in different soil tillage systems 504; S.J. Giacomini, C. Aita, E. Guidini, E.B. Amaral and A. Lunkes; Estimation of nitrogen loading in Japanese prefectures and scenario testing of abatement strategies 507; M. Hojito, A. Ikeguchi, K. Kohyama, K. Shimada, A. Ogino, S. Mishima and K. Kaku; Indicators for environmental and economic sustainability on UK dairy farms 510; E.C. Jewkes, D. Scholefield, M.M. Turner and L. Brown; Dairy production using an extended grazing management system - a preliminary assessment of nitrogen flows 513; E.C. Jewkes, D. Scholefield, M.R. Butler, J. Webb, T. Forrester, J. Lapworth, K. Russell, G. Bailey, A. Lathwood and A. Clarke; Decrease in the amount of residual nitrate in cultivated land 516; R. Lambert, V. Van Bol and A. Peeters; Estimating nitrogen losses from animal manures using their phosphorus balance 518; R. Lambert, B. Toussaint and A. Peeters; Encouraging farmers to utilise nitrogen more efficiently 520; K.A. Leach, J.S. Conway, J.P. Morgan, B.F. Pain and D. Munday; Conserving biologically fixed N to increase its utilisation and decrease gaseous losses 523; A.K. Loes, A.K. Bakken, T.A. Breland, R. Eltun and H. Riley; Effect of animal treading intensity on the efficiency of N2 fixation by clover in mixed grass/clover pasture and potential implications for long-term soil N availability 525; J.C. Menneer, S.F. Ledgard, C.D.A McLay and W.B. Silvester; Effect of type and dose of sewage sludge application in maize+ryegrass rotation in Galicia (NW Spain) 527; M.R. Mosquera-Losada, A. Amador-Garcia and A. Rigueiro-Rodriguez; Cattle slurry and vegetable, fruit and garden (VFG) waste compost in silage maize: fertiliser N no longer needed? 530; F. Nevens and D. Reheul; Applying a ley/arable rotation to reduce N input in forages 532; F. Nevens and D. Reheul; Farm N budgets with estimated nitrogen losses by use of soil N modelling 534; A.H. Nielsen, B.M. Petersen and I.S. Kristensen. Political transformations and nitrogen balances of dairy farms in Poland 536; S. Pietrzak and O. Oenema; Dirty water - a valuable source of nitrogen on dairy farms 539; K. Richards, M. Ryan and C.E. Coxon; Effect of date and dose of sewage sludge application in grasslands production and nitrogen soil concentration in Galicia (NW Spain) 541; A. Rigueiro-Rodriguez, A. Casanova-Vigo and M.R. Mosquera-Losada; Nitrate losses in forestry nurseries using municipal sewage sludge 544; A. Rigueiro-Rodriguez, J. Rasche-Castillo and M.R. Mosquera-Losada; Assessment of measures to reduce nitrogen losses from dairy farms 547; J. Scheringer and J. Isselstein; Nitrogen use efficiency in a water saving ground cover rice production system in Beijing, North China 549; H. Tao, K. Dittert, S. Lin, C. Kreye and B. Sattelmacher; Effect of herbicide, maize variety precocity and sowing date of three winter cover crops on forage yield and on herbage N removal from an intensive double-cropping system 551; H. Trindade, J. Coutinho and N. Moreira; Effects of grassland renovation on herbage yields and nitrogen losses 554; G.L. Velthof and I.E. Hoving; Nitrogen budgets of Flemish specialised dairy farms during 1990-2000 557; I. Verbruggen, F. Nevens, A. Mulier and G. Hofman; Substitution of N fertiliser supply for maize with lupin as a winter crop in rotations under zero and conventional tillage in southern Brazil 559; L. Zotarelli, B.J.R. Alves, E. Torres, S. Urquiaga and R.M. Boddey; Section 6 - Models and decision support systems 563; NGAUGE: A decision support system to optimise N fertilisation of UK grassland for economic and/or environmental goals 565; L. Brown, D. Scholefield, E.C. Jewkes, A. del Prado and D.R. Lockyer; UK-DNDC: a mechanistic model to estimate N2O fluxes in the UK 567; L. Brown, B. Syed, S.C. Jarvis, R.W. Sneath, V.R. Phillips, K.W.T. Goulding and C. Li. MAST - a model of ammonia volatilisation with an examination of abatement strategies for a dairy farm 569; E.C. Jewkes, C.A. Ross, D. Scholefield and S.C. Jarvis; Development of the OVERSEER[registered] nutrient budget model to examine implications of pastoral management practices on nitrogen flows and losses 571; S.F. Ledgard, D.M. Wheeler, C.A.M. de Klein, R.M. Monaghan and K. Johns; The MANNER model: predicting the crop available N supply from farm manure applications 573; F.A. Nicholson, B.J. Chambers, E.I. Lord, K.A. Smith, S.A. Anthony and M.M. Gibbons; The nutrient leaching model ANIMO 575; J. Roelsma, P. Groenendijk and O.F. Schoumans; The SUNDIAL Model 577; J.U. Smith, P. Smith, A.G. Dailey, M.J. Glendining, G. Tuck and P.K. Leech; Section 7 - Themed working groups 579; Organic matter: does it matter, or can technology overcome most problems related to soil fertility? 581; Report by S. Recous and G. Cadisch; Optimising N additions: can we integrate fertiliser and manure use? 586; Report by J.J. Schroder and R.J. Stevens; Controlling gaseous N emissions - what is achievable? 594; Report by R. Harrison and E.M. Baggs; Missing N: is the solution in dissolved N? 600; Report by A.J. Macdonald and D.L. Jones; Pollution problems: mitigation or are we swapping one form of pollution for another? 606; Report by B.J. Chambers and O. Oenema; Systems studies; do we need them, or can they be replaced by desktop studies? 609; Report by H.F.M. Aarts and A. Pflimlin; Model answers: can we improve their level of confidence and applicability? 615; Report by S.F. Ledgard and N.J. Hutchings; Author index 619.