Journal of the Indian Society of Soil Science

Sunnhemp (Crotalaria juncea), Sesbania (Sesbania aculeata), and cowpea (Vigna unguiculata) were grown as greenmanures for three successive years on an acid Silty clay loam soil. The shoot biomass of the three legumes accumulated 103, 84 and 67 kgN ha⁻¹ in 55 days of growth. Sunnhemp showed maximum manurial and soil ameliorative effects. Its use as greenmanure for rice gave crop yield at par with 90 kg fertilizer N when applied alone and equivalent to 120, kg N when supplemented with 40 kg fertilizer N ha⁻¹. Appreciable improvements in certain chemical, physical and biochemical properties of the soil were observed at rice,harvest. Sunnhemp and cowpea showed residual effect on the subsequent wheat crop. but beneficial effects on soil properties observed at rice harvest were not noticed after the harvest of wheat.