A brief description of spatial analysis and superimposing of essential elements in pomegranate using gis technique

Abstract

Spatial variability of soil properties and accompanying variability in plant nutrient concentration in a pomegranate growing enterprise was mapped using GIS technique. About 23 acre land in a farmer's field was selected and intensively sampled on a regular grid spacing of 21 m. Geo-statistical analysis was used to describe the spatial variability. The geo-statistical procedure of Kriging was used for interpolation of grid data to understand spatial correlation between neighbouring observations and to prepare contour maps. Among the essential elements studied, the available Mg in soil showed a good relationship with plant Mg, while for all other elements, the relationship between soil and plant nutrients was very poor. The variogram models of soil properties indicated that most of the properties exhibited definable spatial structures. pH, available N, Ca, Mg, Fe, Mn and Zn showed strong spatial dependence, whereas available P, K and S showed moderate spatial dependence. Most of the plant nutrients exhibited high nugget: sill ratio indicating often mismatch between soil available nutrient and plant nutrient concentration. The extent to which the spatial variability of soil available nutrient mimicked that of plant nutrient status was a function of nutrient element in question. Application of GIS for nutrient mapping was found useful for developing nutrient management strategies in pomegranate.