Quantification of the contribution of N2 fixation to tropical forage legumes and transfer to associated grass

absorption de substances nutritives azote brachiaria brizantha centrosema desmodium ovalifolium feed legumes fixation de l'azote galactia gramineas graminee grasses legumes leguminosas leguminosas forrajeras mineral nutrients minerales minerals neonotonia wightii nitrogen nitrogen fixation nutrient uptake nutrientes minerales nutrition des plantes plant nutrition pueraria phaseoloides stylosanthes guianensis