Spatial Variability of Soil Organic Carbon, pH and Electrical Conductivity and Its Influencing Factors in a Watershed of Coastal Region of Odisha, India

Abstract

ABSTRACT Soil organic carbon (SOC), as a main component of the carbon cycle, contributes to biological and physico-chemical processes in the soil that influence plant growth and soil health. The pH of soil determines how acidic and basic the soil is, while the electrical conductivity (EC) of soil is used to determine the extent of soil salinity. Therefore, the quantification and spatial distribution of these soil properties are important for agricultural crop planning. In this study, the spatial variability of SOC, pH, and EC in soils of a watershed in Nayagarh (Odisha, India) was analyzed using geostatistical (ordinary kriging) techniques. The study revealed that the experimental semi-variogram of SOC and EC fits well with the spherical model; however, the Gaussian model was found to be the best fit for soil pH. The coefficients of variation for SOC, pH, and EC were 15%, 7.63%, and 40.3%, respectively, which suggests SOC may have moderate variability. SOC had moderate spatial variability, as shown by the nugget to sill ratio. The geostatistical method was able to accurately assess the spatial variability of SOC content and its influencing factors at the study watershed. The findings could help decision-makers and farmers in developing more effective land resource management.