Evaluation of greenhouse gas emissions and design of mitigation options: a whole farm approach based on farm management data and mechanistic models

Agricultural activities are important sources of nitrous oxide (N<SUB align="right"><SMALL>2</SMALL></SUB>2O), methane (CH<SUB align="right"><SMALL>4</SMALL></SUB>) and carbon dioxide (CO<SUB align="right"><SMALL>2</SMALL></SUB>). They contribute approximately 10% of the total emitted greenhouse gases (GhG) in the European Union. We search for evaluating GhG emissions at the farm level and designing mitigation options. As emissions occur at many stages within the farm operation, it is crucial to consider nutrient cycling and farm working. Our proposal comprises three characteristics: an integrated farm approach which combines empirical and mechanistic modelling through describing C and N fluxes through two coupled models of land use: a farmers' practices description; and system boundaries limited to the farm gate, but including also pre- and post-chain effects. We used a case study located in semi-continental conditions (Mirecourt - North-Eastern France). The simulated farming system is a mixed dairy and crops system so as to account for a rather generic farming system.