Predicting the fertilizer nitrogen value of farm manure applications to agricultural land

摘要

A computer based decision support system to predict the fate of N following organic manure applications to land was developed, drawing together the latest research information on factors affecting manure N availability. The MANure Nitrogen Evaluation Routine (MANNER) accounts for manure N analysis, ammonia volatilisation, incorporation timing, nitrate leaching and mineralisation of manure organic N. Predictions from MANNER have been evaluated by comparison with independently collected experimental data. Good agreement was found between predicted and actual fertiliser N values for poultry manure, pig slurry and cattle slurry (p < 0.001), confirming that MANNER provides a simple, quick and accurate estimate of the fertiliser N value of different farm manures spread under a range of circumstances.