Spatial variability of nitrate content in different soil layers in the Shunyi District of Beijing
北京市顺义区浅层土壤硝态氮的空间变异特征分析

Shunyi is an important water resource and agricultural production base of Beijing. Studies on the nitrogen accumulation in soil and its spatial variability are significant to understand the potential pollution in soil, and guide agricultural practice to prevent non-point source pollution. Traditional statistics and geostatistics based on GIS were used to analyze the spatial distribution of nitrogen in different soil layers. Considering the anisotropy and trend effects, the nitrate content in different soil layers are all spatially correlated. The theoretical variogram models of spherical and exponential forms fit the data well. Spatial distribution maps of nitrate content for the research area were created by ordinary Kriging interpolation. The results showed that the nitrate had a strong variability among the different layers, and in general, the nitrate content in the east part is higher than that in the west.