An indicator of the efficacy of green manure incorporation is soil organic matter (SOM), an important source of nutrients for plant growth that needs to be maintained for agricultural sustainability. Conventional farming can result in organic matter loss, and yield degradation in cultivated soils (Lal, 1996). The effect of organic matter amendments by green manure on soils has received renewed attention recently under low external input situations. A comparison of organic and mineral fertilization in soil showed higher SOM and total N for organic-matter amended soils (Nkonya et al., 2005 and Marin et al., 2007). The amount of SOM accumulation in soil can vary depending mainly on decomposition rate and the type of green manure.