Application of Geostatistical Techniques in Spatial Variability Mapping of Soil Fertility– A Review

Soil fertility is one of the key factors of agricultural crop production. Spatiotemporal database and digital mapping of soil fertility at different scale from field level to country level has tremendous utility in development of agricultural sector. Geo-statistical tools in geographic information system (GIS) have potentiality to describe the spatial pattern using semiovariogram analysis and to carry out spatial interpolation of soil properties including macronutrients and micronutrients by kriging methods. Now–a-days, several kriging techniques like ordinary kriging, universal kriging, co-kriging, multivariate kriging, indicator kriging etc. are used for spatial interpolation of soil fertility parameter, based on nature and interrelationship of soil attributes and other external information. Farm and district level nutrient mapping are being effectively utilized for precision farming, increased input use efficiency, enhanced agricultural productivity, sustainability and environmental safety as well as policy making for fertilizer allocation in different states.