Researcher in Ecophysiology of meadows and fodder plants at the INRA Center in Lusignan (86600) from 1974 to 2010. Conducted research on the nitrogen nutrition of fodder stands and its impact on the production and quality of fodder and more generally on the nitrogen nutrition diagnosis of crops. He has also conducted research on grassland ecology and on grass-animal interactions in pasture and the optimization of grassland management both from the point of view of animal production and environmental impacts. He was involved as deputy head of the Agronomy Department then Environment & Agronomy in the research strategy of INRA for ten years. He has notably collaborated scientifically with Australia, New Zealand and Brazil. He is the author of 120 international scientific articles, 32 book chapters and more than 200 popular articles. He retired in 2010, but remains active on the editorial boards of numerous international scientific journals. He has been a member of the French Academy of Agriculture since 2011.