Towards a pact to achieve an impact : what kind of agronomic research can contribute to the evolution of agricultural practices ?

The aim of agronomic research has traditionally been to describe how the climate-soil-plant complex works when submitted to the actions of human beings. These general laws of operation allow the prediction of change, and hence must allow the farmer to act upon his or her "climate-soil-plant" complex in a particular way that conforms more with his or her interests. The agronomist, a technician of nature, is then asked to influence the processes and results of agriculture according to an implicitly universalist principle. The blueprints elaborated as a result of this process are technically viable and economically efficient, however their social validity remains ambiguous. The systemic approach to agronomy has been constructed as a reaction to this ambiguity: a generalist approach to agronomy which focuses on understanding the results of climate-soil-vegetation relations governed by the producer in order to satisfy his objectives. This approach can be placed at the intersection between the decision-making system and the bio-physical system, since a technical intervention is at the same time a choice, a practice and a factor in the yield elaboration. From the sustainable development perspective currently widely invoked, it is rather the agronomist's negotiation skills and abilities in building and managing a veritable social pact with local actors, that will allow him or her set in motion a technico-socio-economic process to achieve an effective social impact, in terms of better control by the actors of their farming systems and their environment