Assessment of Spatial Variability of Soil Available Sulphur Using Geostatistical Techniques in a Part of Deccan Plateau of India

Abstract

Soil heterogeneity, soil formation factors and other human induced activities cause spatial variation of soil
available nutrients. Knowledge on spatial variability of soil nutrients is essential for their successful
management in crop field. Soil available sulphur (S) is an important secondary nutrient and it may vary
spatially at any scale. Hence, the present study was conducted to assess the spatial variability of soil
available S using geostatistical techniques. About 132 georeferenced surface soil samples were collected
form a cultivated area of Katol block of Nagpur district, Maharashtra, India. Soil available S was determined
chemically and the descriptive statistical analysis of S showed its good variability in terms of per cent
coefficient of variation (CV= 81.74%). The results of geostatistical analysis showed its spatial variability in
terms of nugget: sill ratio (NS ratio). The NS ratio i.e., 0.37 indicated moderate spatial dependency of soil
available S. The exponential model was found as a best suited semivariogram model for describing the
spatial trend of soil S. Ordinary kriging (OK) technique was employed to generate spatial variability map of
soil S to identify specific management zone of S. The present investigation suggested that the study area
has moderate S content except north-east corner of the area, which is high in S content. Specific management
of S is necessary to the central and north-west sides of the cropped areas of the study site. Thus, the study
indicated a good potential of geostatistical technique especially with OK technique to generate S variability
map for effective S management of the study area.