Abstract:Daxing County, located south of the city of Beijing, was taken as a case study for illustrating soil fertility change. The 1∶50,000 soil map produced in the Second National Soil Survey (SNSS) in 1982 was digitized with GIS supporting. Top soil samples were collected from the same soil sampling sites of the 1∶50,000 soil map with GPS reference locations, from May to June 2000. Three samples collected around each sampling point were mixed and a quarter of each sample was kept for laboratory analysis. At the s...