Intercropping of sesbania (Sesbania sesban) and leucaena (Leucaena leucocephala) with five annual grasses under semi-arid conditions as affected by inoculation with specific rhizobia and associative diazotrophs

Intercropping of legumes and non-legumes is considered to improve the quali ty and quantity of field forage crops. Under semi-arid desert conditions, i ntercropping of leucaena and sesbania with some annual grasses (barley, pea rl millet, and Rhodes-, rye- and sudan-grasses) was evaluated in a series o f field trials. Inocula of specific rhizobia for legumes and a composite of associative diazotrophs for non-legumes were applied in the presence or ab sence of N fertilizers. Rhizobia inoculation was indispensable, and support ed better growth of legumes which extended to the neighboring non-legumes. Associative diazotrophs improved biomass and N yields of non-legumes, parti cularly in the presence of moderate N fertilization for winter barley and r ye grass and of higher doses of 300 kg N.ha(-1) for summer pearl millet and sudan grass. Intercropping improved productivity of non-legumes, in partic ular barley mixed with sesbania, and the calculated N-transfer from legumes to non-legumes ranged from 20 to 70 kg N.ha(-1).