Spatial variability of soil fertility in Daxing District of Beijing

The objective of this study was to explore the spatial variability of soil fertility indices and soil fertility quality, and to provide guidance for soil fertilization management. Soil indices selected included soil organic matter, total N, available P, available K and pH value. Geostatistics method and fuzzy comprehensive evaluation method were used to analyze the data. The results showed that the C0/(C+C0) of organic matter, total N, available K and pH value were 0.38, 0.25, 0.29 and 0.50, respectively, which demonstrated moderate spatial dependence. The C0/(C+C0) of available P was 0.88, which demonstrated weak spatial dependence. Soil organic matter and total N decreased from north to south; available P decreased from southwest to northeast; available K decreased from southeast to northwest; pH value decreased from south to north. The fertility quality of Daxing District decreased from north to south. The five categories of fertility quality covered 0.21%, 6.35%, 20.95%, 29.45% and 43.04% of the total area, respectively. The third category, fourth category and fifth category covered 93.44% of the total area. The fertility quality of Daxing District was generally low, which was affected by soil texture and artificial cultivation management.