Effect of Land Use Changes on Soil Conditions in the West Songnen Plain: A Case Study in Tongyu County, Jilin Province

Soil sample data collected from 2006 and 1982 were linked with land use attributes derived from satellite images and analyzed by using traditional statistics, geostatistics and GIS. Traditional statistics showed that the mean value of each soil nutrient was very low. The mean value of TN, TP in 2006 were significantly lower than those in 1982 and other soil nutrients didn´t have statistically significant difference between 1982 and 2006. Based on Markov transformation matrix, the predominant conversions between land uses were identified. By point to point comparison, we found the main land use conversion resulted in the decrease of soil fertilities in Tongyu County in 20 years. The results of ANONA indicated that cropland, woodland and grassland didn´t have significant difference on SOM, TN, and AN, AP. The concentration of TP in woodland was significantly lower than other land use types. The spatial distributions of soil nutrients under different land use types have similar characteristics that the low level of soil nutrients had large area distributed under each land use types. Land use type was not the main controlling factor of soil nutrients variety in this study area, and the probably factors may be parent material, topography, fertilizer, etc.