Distribution of organic carbon in particle size fractions under different cropping systems of Karnataka

The clay fractions had higher organic carbon content in coffee cropping system in comparison to areca and paddy. Similarly, carbon content in silt fraction was higher in coffee cropping system as compared to paddy and areca systems. The organic carbon content in sand fraction was low in areca cropping system as compared to coffee and paddy. In paddy cropping system, clay, silt and sand contributed 48.0, 29.4 and 22.6% carbon, respectively, to soil organic carbon. Similarly in areca and coffee system clay, silt and sand contributed 52.7, 28.7, and 18.6% and 48.4, 34.6, and 17.0% carbon, respectively to soil organic carbon.