FARM-N

This site is under construction

Extended summary

The close relationship between farm N surplus and losses of N to the environment mean that N surplus is increasingly being used as an environmental indicator. The advantage of farm N surplus is that they can accurately and reliably be calculated using readily available data at both individual farm, regional and national levels. A similar credibility cannot be associated with field level N surplus particularly on cattle farms where much of the internal flows cannot be measured. In Denmark, use of such surpluses in environmental regulation is under review and the farming industry has shown interest in nutrient balances as a management tool. However, the integrative nature of N surpluses contrasts with national and international legislation, which relates to specific N compounds. Farmers and regulators need to estimate how farm N surpluses are partitioned between the different N loss routes, and on-farm accumulation of N. Farmers and advisors need tools to allow them to decide the most appropriate management to limit farm N surpluses. Losses of different N compounds are often linked, e.g. a new manure application technique to reduce ammonia volatilisation will increase amounts of N in the soil and could increase both nitrate leaching and nitrous oxide emission. It is therefore important to take a holistic approach to nutrient management.
DIAS has constructed a whole farm model (FASSET) that includes a dynamic simulation of N flows within a single farm (www.fasset.dk). The philosophy fundamental to FASSET is that the partitioning of farm N surpluses and the prediction of farm management on the partitioning is only possible if the model represents the underlying processes. The FASSET model has a flexible, modular format, enabling it to be adapted to a wide range of types of animals, housing, manure storage, crops, soils and climate conditions.
The overall objective of the project is to move FASSET from being a research model into an advisory tool. This will require further research and development mainly to ensure robustness of the model and the associated tool, and this is the basis of this project. The project will include the development of modules for additional crops, animal feeding modules and for grassland management. All new and some existing crop modules will be parameterised and tested. The animal housing and manure storage modules will be subjected to testing and parameterisation with respect to ammonia volatilisation, as will the existing soil model with respect to nitrate leaching, denitrification and changes in the soil organic N. The testing and parameterisation will be based on representative datasets for each N loss or accumulation pathway.
The model will be tested at the farm scale using data from about 50 intensively studied commercial farms (‘Study farms’). This will require technical development of a link between FASSET and the Study farm database, a link that will also enable FASSET to communicate with the farm management system owned by the Danish Agricultural Advisory Centre (DAAC).