Predominant Cropping Systems affect Soil Organic Carbon Content in the Soil Profile of North–West India

The soil organic carbon (SOC) content depends on the physiography, climatic conditions, soil type, and cropping patterns of a particular region. The improvement in soil health contributes to better productivity of the soil. The present study focused on the estimation of the organic carbon content in soil profile of predominant cropping system in Karnal and Kaithal districts of Haryana. Soil samples were collected at four different depths viz., 0–0.15, 0.15–0.30, 0.30–0.45 and 0.45–0.60 m from the different predominant cropping systems for the estimation of pH, electrical conductivity, and fractions of organic carbon and calcium carbonate content (CaCO3). The organic carbon was greater at the surface and decreased along the depth in all the cropping systems in Karnal district. The total organic carbon (TOC) in soil for Karnal district was higher (11 g kg-1) in the vegetable–vegetable system. In Kaithal district the Walkley Black organic C content was greater in the surface soil (0–0.15 m depth), then a decrease at the sub–surface (0.15–0.30 m), followed by 0.30–0.45 and 0.45–0.60 m depth. The rice–barseem/rice–wheat and sugarcane–sugarcane maintained a higher amount of TOC (8.03–9.19 g kg–1) in surface soil. Irrespective of the cropping system and region, total OC and its oxidizable fraction showed a negative correlation with CaCO3. The alkaline to moderately alkali soils presented higher values of pH with poor performance of crops resulting in lower root biomass return to soils and low C content. This study will provide valuable insights for formulating better management practices in soils inclined towards degradation to achieve goals of sustainable land use in predominant cropping-systems in Haryana.