NITROGEN-FIXATION AND ITS TRANSFER FROM LEUCAENA TO GRASS USING N-15

Nitrogen fixing capacity of Leucaena diversifolia upon inoculation with different strains of Rhizobium was assessed by isotope dilution technique, and nitrogen transfer from this legume to Cenchrus ciliaris grass was quantified using N-15 enrichment through foliar feeding. Inoculation improved the dry matter production and nitrogen content. This effect varied from one strain to another. About 42-54% of the nitrogen was found to be derived from fixation. Biomass production and N accumulation of grass growing along with Leucaena were enhanced compared with monocultured plants. Detopping of Leucaena further increased N concentration in grass. N-15 was detected in both leaves and roots of intercropped grass and the percentage of legume N recovered in grass varied from 3.07 to 3.87%. Further, grasses growing with detopped plants had higher % N obtained from Leucaena compared with that of non-detopped plants.