Caractérisation fonctionnelle d'espèces utilisées en cultures intermédiaires et analyse de leurs performances en mélanges bispécifiques pour produire des services écosystémiques de gestion de l'azote
Cover crops produce ecosystem services for nitrogen management during fallow period such as decreasing nitrate leaching and producing green N manure effect for the next cash crop. The aim of this work was to characterize a large number of species using a functional analysis and to analyze the performances of bispecific legume/non-legume mixtures to simultaneously produce both ecosystem services. Leaf functional traits measured on 36 cover crops were found robust but lacked of precision in differentiating species strategies. The cardinal temperatures for germination measured in laboratory have shown that the majority of species is adapted to summer sowing conditions. A conceptual model was designed and implemented in GLM to predict the behavior of species in mixtures. The measurements carried out in field experiments coupled with STICS model simulations confirmed the potential efficiency of some bispecific mixtures to simultaneously produce ecosystem services of nitrogen management. This efficiency depends on the choice of the two species to associate which must be adapted according to the pedoclimatic conditions as well as the date of cover crop destruction
