The Trend Variability of Soil Salt Content in the Representative Fluvo-aquic Soil Area

By means of analyzing salt content of 100 soil sampling points of Yucheng city where locates in the representative Fluvo-aquic soil area in Shandong province in 2003 ,the article studied the temporal and spatial variability of salt content by coupling geostatistics theory with geographic information system, also analyzed the trend variability of soil salt content on the region scale in soil arable layer. With the help of the temperature and precipitation within 50 years, the article also analyzed the change cause of soil salt content in the research area, and the decrease of salt content provided good conditions for the increase of SOM content and effective nutrient content. The research results showed that soil salt content characteristic is normal distribution(after log transformation),the semivariogram model of soil salt content is fitted with spherical model, the nugget/sill ratio, soil salt content had exhibited middle spatial correlation ,which results from structure and stochastic factor together.