[en] This project first aimed at the development of a modelling, at a scale consistent with an economic decision, the relationship between inputs such as nitrogen or mineral supplies and crop efficiencies, and secondly at studying impacts of climate change on the European agriculture sector. More precisely, the agronomic objective was to generate curves of responses of efficiency to nitrogen fertilisation (these curves depend on soil conditions, climate and technical aspects). As far as economy is concerned, the objective was to develop an automatic method and to use it within the context of the economic database for some typical regions and typical farms, and then to develop a coupling with the AROPAj model.