MAPPING SPATIAL VARIABILITY IN SOIL PROPERTIES AND FERTILITY AT FIELD-SCALE IN BASALTIC TERRAIN FOR SITE-SPECIFIC AGRICULTURAL INPUT MANAGEMENT USING GEOSPATIAL TECHNIQUES

摘要

Soil sampling at large number of places is costly and time consuming and warrants to predict the soil properties and nutrient status at unsampled location from sampled locations using spatial dependence of soil properties through interpolation with reasonable accuracy. Soil samples (0 to 20 cm depth) were collected from a regular grid of400 by 400 m from Savli village (basaltic terrain) and analyzed for soil physical properties (particle size, bulk density), hydraulic properties (moisture retention at -33 kPaand -1500 kPa), chemical properties (pH, organic carbon, cation exchange capacity), soil available macronutrients (N, P, K) and micronutrients (Fe, Mn, Cu, Zn). Spatial variability was quantified through semivariograih analysis and the respective surface maps were prepared through ordinary kriging. Sand, pH, OC has displayed strong spatial dependence whereas, silt, clay, bulk density, cation exchange capacity, moisture retention at -33 kPa and -1500 kPa, available N, P, K, Fe, Mn, Cu and Zn showed moderate spatial dependence. Bulk density, organic carbon, and available Zn were spatially correlated for a short range. The kriged maps of soil properties and soil fertility generated may be useful for better management decisions.