Spatial analysis and assessment of soil fertility by using GIS and kriging method

Studying soil fertility through the spatial distribution of soil nutrients is necessary for sustainable management of land resources. This investigation was conducted to understand the spatial variability and distribution of trace elements and macronutrients, and soil fertility in agricultural soils by using geostatistics combining with GIS. The sources of´ top soil nutrients variability in agricultural area were evaluated in Chongming island of Shanghai. According to the Nemoro formula, the overall coefficient of soil fertility in the island was derived from the coefficient of soil single factor fertility that was calculated based on the Kriging interpolating result. The results show that the dilemma of global generalization and local accuracy of the interpolation can be harmonized for the using of Multi-scaled model. The error of universal Kriging was existed in these soil nutrient factors and the anisotropism of these factors was affected by the soil salinity to different extent.