Spatial Variability in Soil Micronutrients and Soil Separates of Ujjain Tehsil of Ujjain District of Madhya Pradesh, India

Mapping of soil properties is an important operation as it plays an important role in the knowledge about soil properties and how it can be used sustainably. Knowledge of soil variability of any region is crucial for development of site-specific management practices for that region as this will enhance the crop productivity and maintain the good soil health. With this background, present study was conducted to quantify the spatial variability of different soil physical properties and soil available micronutrients in Ujjain tehsil (Ujjain) district of Madhya Pradesh state, India. A total one hundred fifty geo-coded surface (0-15 cm depth) soil samples, were collected across the study area. These samples were analyzed using standard method for different some soil properties viz: soil texture (sand, silt and clay) and soil available micronutrients, viz. extractable zinc (Zn), copper (Cu), manganese (Mn) and iron (Fe) in laboratory. The range of sand, silt, clay, Zn, Cu, Fe and Mn in the study region were varied from 9.15 to 24.06 %, 24.00 to 41.55 %, 40.20 to 58.60 %, 0.12 to 1.66 mg kg-1, 2.06 to 6.22 mg kg-1, 3.70 to 10.40 mg kg-1, and 2.41 to 14.64 mg kg-1, respectively. The data were analyzed using standard statistical methods and geostatistics, which included creating semi-variograms and mapping by standard kriging procedures. Semi-variograms were produced for soil properties and their regional distributions were plotted. The observed soil parameters were best represented by four models: Exponential, Circular, Gaussian, and Hole effect. The modelled variables showed strong and moderate spatial dependencies, as demonstrated by the Nugget/Sill (Co/Co+C) ratio. The distribution maps of soil features may serve as a reference for implementing site-specific crop management in soils with comparable characteristics. Further, this research indicates the relevance of GIS- application in soil variability investigations.