Quantification of nitrogen fluxes and explanatory plant traits during a two year legume-cereal rotation

National audience; A better understanding of how plant growth, N nutrition and symbiotic nitrogen fixation (SNF) are influenced by soil inorganic N availability, for a wide range of legume species, is crucial to optimise legume productivity, N2 fixation, while limiting environmental risks such as N leaching. A comparative analysis was performed for ten legume crops, grown in a field experiment and supplied with four levels of N fertiliser. Dry matter, N concentration and SNF were measured. Parallely, root traits were studied in a greenhouse experiment. For most species, inorganic N inputs had little effect on plant growth and N nutrition. SNF was negatively affected by soil inorganic N avai…