Objective TO STUDY THE CHANGES IN MINERALISATION AND IMMOBILISATION OF NITROGEN IN SOILS SUBJECTED IN CONTRASTING TILLAGE METHODS. THE RESEARCH PROGRAMME WILL EXAMINE, BOTH IN FIELD AND LABORATORY EXPERIMENTS, THE INCORPORATION OF NITROGEN-15 LABELLED FERTILISER AND UNLABELLED SOIL-DERIVED NITROGEN INTO CROP PLANTS AND SOIL ORGANIC MATTER AND ITS SUBSEQUENT RELEASE BY MINERALISATION AFTER HARVEST OF THE AERIAL TISSUES. FRACTIONATION OF THE SOIL ORGANIC MATTER ON BOTH A CHEMICAL AND BIOLOGICAL BASIS WILL BE ATTEMPTED TO DISTINGUISH THOSE FRACTIONS THAT, BY TURNING OVER RAPIDLY MAKE THE LARGEST CONTRIBUTION TO SOIL MINERAL NITROGEN SUPPLY. SOILS THAT HAVE BEEN DIRECT-DRILLED OR PLOUGHED WILL BE USED, TOGETHER WITH THOSE UNDER PERMANENT PASTURE. IN ONE FIELD EXPERIMENT THE INTERACTIONS OF DRAINAGE AND CULTIVATION WILL ALSO BE EXAMINED. Programme(s) PRE-ENVPROT 3C - Sectoral research and development programme (EEC) in the field of environment (environmental protection and climatology) - indirect and concerted actions - Environmental protection -, 1981-1985 Topic(s) Data not available Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator BBSRC Institute of Grassland and Environmental Research EU contribution No data Address Aberystwyth Research Centre Plas Gogerddan SY23 3EB Aberystwyth United Kingdom See on map Total cost No data