Effects of Various Green Manures on rice Yield in Irrigated Areas

Abstract

Three leguminous green manure (GM) crops viz., Sesbania rostrata, Vigna sinensis and V. radiata were Planted at chinat Rice Research Station during 1987-1991. The studies aimed at the GM crops impact on wet season rice and the change of the soil properties. the experminetal design was RCB with 4 replicates and 4 treatments (3 GM crops and control). The result stated that fresh weight of S. rostrat at 50 days after seedlings (DAS) gave the highest yield, 3,039 kg/rai, while those of v. sinensis at 50 DAS and V. radiata at 35 DAS were 2,045 and 1,687 kg/rai respectively. S. rostrata gave the highest Nitrogen content, 11.8 kg/rai, while v. sinensis and V. radiata gave the contents of 60.0 and 4.85 kg/rai respectively. All the GM crops improved rice yield by 7-12% when compared with control. Rice grown after S. rostrata showed the highest yield of 740 kg/rai while those grown after v. sinensis, V. radiata and control were 713, 706 and 658 kg/rai respectively.
The result of sort analyses after 4 years of continuous GM crops plantation showed that the organic matter, P,K and cation exchange capacity (CEC) were increased and were greater than the control plot. Hence, the sesult of this study indicated that incorporation of GM crops before rice plantation improved rice yield and soil properties.