GROWTH AND N2-FIXATION OF 2 STEM-NODULATING LEGUMES AND THEIR EFFECT AS GREEN MANURE ON LOWLAND RICE

Two stem-nodulating tropical legumes (Sesbania rostrata and Aeschymmene afraspera) show promise as green manure in lowland rice farming systems. Their performance as biofertilizers for lowland rice was studied at different growth stages, seasons and sites. Both species exhibited fast growth and high N2 fixation and produced high biomass in a short growth period. Due to photoperiod sensitivity, the use of S. rostrata was limited during the short-day period. A. afraspera was found to be less sensitive to photoperiodism. Both species increased significantly the grain yield of rice. In the short-day period A. afraspera seemed superior-its productivity is higher than that of S. rostrata. In the long-day period, the same increase in yield was reached with both species but A. afraspera had lower biomass and was less labor-intensive to incorporate into soil. © 1990.