A preliminary investigation was conducted in 1 m2 microplots using two stem nodulatedAeschynomene species,A. afraspera andA. nilotica, to evaluate their beneficial effects as green manure on the yield and the nitrogen content of rice.A. afraspera andA. nilotica yielded 7.5 and 9.2 kg m−2 of fresh matter, (42.3 and 53.2 g N m−2 respectively) in 7 weeks growth. Green manuring increased grain yield by more than 80% over the control and by 45% over rice fertilized with 10 g N-urea m−2. The nitrogen content of grain and straw was significantly higher in treatments with Aeschynomene green manure than in other treatments.