Spatial Variability of Soil Nutrients in Tobacco Fields Based on Geostatisics with Small Scale

Spatial distribution of soil available nitrogen, available phosphorus, available potassium, organic matter, and pH in tobacco fields was studied to provide theoretical basis for precision agriculture by using geostatistics and GIS technique on small scale. The results indicated that soil available nutrients had medium variability with coefficient of variation from 4.43% to 33.45%. Semivariogram analysis showed that soil nutrients were moderately spatially dependent in a given spatial range, except that soil organic matter was strongly spatially dependent and available nitrogen was not spatially dependent. The semivariograms of soil nutrients were best described by exponential model, except for that of available N, which was best fitted by linear model and pH was best fitted by spherical model. The distributing maps of soil nutrients were drawn by using ordinary kriging, and the distributing results of soil nutrient were analyzed. The study provides an important basis for precision fertilization in tobacco production.