Recycling organic wastes of various kinds is a way to improve agriculture sustainability. Modelling agricultural systems for simulating scenarios and assessing their agronomical and environmental performances necessitates the integration of heterogeneous data and knowledge on both the biophysical processes involved and farming practices. We will describe our main methodological achievements relevant for modelling farming systems on whole-farm or territory scales; representing human activity situated in time and space; using the resulting simulation models for assessing recycling scenarios. (Texte intégral)