Defra - Department for Environment, Food and Rural Affairs.

Science Search

Science and Research Projects

Return to Science Search homepage   Return to Project List

Fate of nitrogen from organic manures - NT1501

Knowledge on the release of N from the organic N fraction of manures and its availability to growing crops in the short term and longer term is imprecise. This uncertainty presents a major barrier to the efficient use of organic manure N and reduction of nitrate leaching losses. This study will aim to improve understanding of the processes controlling N mineralization from the organic N fraction of farm manures, in order to predict the longer term effects of manure applications on soil N supply. Studies will be conducted to characterise the organic N fractions of farm manures (cattle/pig FYM, cattle/pig slurry and poultry manure); fractions obtained will be related to N mineralization studies in the laboratory and under field conditions. The field experiments will study N mineralization dynamics, following the single application of a range of ammonium N striped manures at 3 contrasting field sites. Short and medium-term N release will be measured via grass N uptake and nitrate leaching measurements. N release in the field will be related to the laboratory incubation studies and chemical composition of the manures, taking into account variations in soil moisture and climatic conditions at each of the field sites. The combined information will be incorporated into the ADAS manure N decision support system (MANNER), to enable improved guidance to be provided to farmers when allowing for manure organic N supply in their fertiliser policies.
Time-Scale and Cost
From: 1995

To: 1998

Cost: £312,551
Contractor / Funded Organisations
Institute of Grassland and Environment Research (IGER), ADAS UK Ltd.
Fields of Study
Fertilisers and Nitrate Pollution