Spatial variability of tobacco soil nutrients by micro sampling scale

In order to promote accurate management and proper fertilization of tobacco soil,spatial analysis on tobacco soil nutrients was conducted by GIS and geostatistics in the tobacco region of Wulong.The results showed that soil fertility factors were all at moderate levels in the whole research region except available phosphorus.The semivariograms for soil organic matter,and available nitrogen,phosphorus and potassium contents were all well fitted by spherical,exponential,exponential and spherical models.Soil available nitrogen and potassium showed strong spatial correlation,while soil organic matter and available phosphorus showed moderate spatial correlation.Ordinary Kriging method was applied to interpolate soil available elements in the research region.The results showed that available phosphorus was widely deficient in the research region,and the contents of soil organic matter,available nitrogen and potassium were at moderate levels,indicating all apparent discrepancy in the research region.