Long – term effect of integrated nutrient management on soil organic carbon fractions in vertisol under sorghum wheat cropping system

Abstract

The field experiment was conducted the year 2014-2015 on the old long-term fertilizer experiment started since 1983 to assess the long – term effect of integrated nutrient management on soil organic carbon fractions in vertisol under sorghum wheat cropping system. The study showed that there was slight decrease in soil bulk density and calcium carbonate increase in porosity and water holding capacity and slightly increase pH and EC of soil over 33 years of sorghum-wheat cropping system receiving organic manures in combination with inorganic fertilizer. And it was observed that various forms of carbon and fractions of humus tended to decrease with depth and use of organics like subabul and FYM in conjunction with NPK fertilizers exerted a remarkable impact on the distribution and built up of various carbon and humus fractions in soil.