Abstract
The nitrogen content and the amount and rate of mineralization of some tropical grain legume roots varied considerably not only among different species but also between cultivars of the same species (cowpea). The nitrogen content of the legume roots examined ranged from 1·25 to 3·93 per cent. Transformation of root ranged from mineralization of about 49 per cent of added Bambara groundnut root to complete immobilization of added soya bean root in 84 days of incubation. These results suggest that the conflicting reports of the effects of grain legume, especially cowpeas, on soil may be due in part to varietal difference
