Study on the changes of the cultivated soil fertility in Liling county based on GIS

This paper study the changed characteristics of cultivated soil quality in space and time of Liling county, based for the management of the soil nutrition in precision agriculture. The main results included that the available nitrogen nugget was largest; The substrate effect of the pH, available nitrogen, soil available phosphorus and available potassium was from 25% to 75%; the soil pH decreased, while the available nitrogen, soil available phosphorus and available potassium improved, where the speed of the pH and the soil available phosphorus was fast; according to the research of temporal variations stability, the soil pH of Liling was generally the middle-class stability MI level; the soil available nitrogen was generally the middle-class stability MIII level, while the available potassium and available phosphorus was generally the middle-class instability UIII level.