INVESTIGATION OF SPATIAL VARIABILITY OF NUTRIENTS IN PURPLE SOIL IN JIANGJIN --WITH THE GEOSTATISTICAL METHODS

Geostatistical methods were used in combination of GIS information to analyze the spatial distribution characteristics of organic matter, and available nitrogen, phosphorus and potassium in the 0～20 cm layer of purple soil in Jiangjin, Chongqing. The results indicated that the organic matter, available nitrogen, available potassium showed a normal distribution, others with a lognormal distribution; Semi-variogram analysis showed that the 4 soil nutrients were correlated in a given spatial range. Using the group maps of the soil nutrients with Ordinary Kriging to make a preliminary evaluation of soil fertility, it was found that second-grade soils accounted for 90% of the entire area. These results showed further application in precision agriculture.