Soil organic carbon stocks, storage profile and microbial biomass under different crop management systems in a tropical agricultural ecosystem

We investigated the soil organic C and N stocks, storage profiles and micro bial biomass as influenced by different crop management systems in a tropic al agricultural ecosystem. The different crop management systems significan tly affected the C and N stocks and microbial biomass C and N at different soil depths. Amongst the systems evaluated, the rice-wheat system maintaine d a higher soil organic C content. Inclusion of legumes in the system impro ved the soil organic matter level and also soil microbial biomass activity, vital for the nutrient turnover and long-term productivity of the soil. Ir respective of the cropping system, approximately 58.4%, 25.7% and 15.9% of the C was distributed in 0-15, 15-30 and 30-60 cm depths, respectively.