Assessing the Spatial Variability of Soil Physical Properties of the Lesser Himalayas in India

Abstract

Understanding the spatial variability of soil properties is crucial for assessing the impact of measures taken to address land surface processes such as soil erosion and water pollution. It is also vital for recommending effective land management strategies. The present study was conducted to assess the spatial variations in soil textural fractions (sand, silt, and clay), bulk density and porosity. Soil samples were collected from 115 randomly selected locations using the Global Positioning System (GPS). The samples were taken at an average depth of 0-20 cm. A thorough examination was carried out in the laboratory to assess the physical properties of the soil. Afterwards, there was an analysis conducted to characterise the physical properties of soil and understand how they vary across different locations. The measured soil properties showed low to very high variability (6.26- 37.2%) for the Coefficient of variation (CV). The spatial dependence of soil properties was observed through the weak to strong nugget-to-sill ratios. Mapping the spatial variability of soil parameters involved using the Ordinary Kriging (OK) approach of Geostatistical analysis. This method helped identify the best-fit models for different soil parameters, such as Spherical for Silt, bulk density and porosity. Exponential for clay; and Gaussian for sand these spatial interpolation maps can be a valuable tool for pinpointing areas of land degradation in the study region and recommending specific land management strategies.