Spatial assessment of soil organic carbon and its stock across diverse land use systems in Kolhapur district, Maharashtra

Abstract

Soil Organic Carbon (SOC) plays a pivotal role in maintaining soil health, enhancing crop productivity and mitigating climate change through carbon sequestration. This study evaluates the spatial variability of SOC content and its stock across Kolhapur district, Maharashtra, using a grid-based soil sampling approach, laboratory analysis and geospatial interpolation techniques. Total 109 surface soil samples (0-15 cm depth) were collected across diverse Land Use and Land Cover (LULC) types, including forest, agriculture, barren land, hilly regions and settlements. SOC content was determined using the Walkley-Black titration method and SOC stock was calculated by integrating bulk density and SOC data through GIS-based spatial analysis. Results revealed a wide variation in SOC content (0.9% to 2.71%) and SOC stock (1.40 to 56.22 t/ha), with forested and hilly areas exhibiting higher carbon storage due to favourable topography and vegetative cover. In contrast, intensively cultivated eastern tehsils such as Shirol and Kagal showed lower SOC values, likely due to continuous cropping and residue removal. Interestingly, some barren and settlement areas showed elevated SOC stock, possibly reflecting past vegetation or minimal disturbance. Spatial distribution maps highlighted a west-to-east decline in SOC, indicating topography and land use as key drivers. These findings underscore the importance of adopting site-specific soil management and conservation practices to enhance SOC levels, particularly in degraded agricultural zones of the district.