Effect of land use and soil management practices on soil fertility quality in North China cities' urban fringe

The objective of this study was to explore the spatial variation of soil fertility quality and the influence factors of human land use and soil management practices on soil fertility quality in North China cities' urban fringe of Beijing using data for 2007 and grey relational analysis (GRA) and geographic information systems (GIS). Soil total nitrogen, available phosphorus, available potassium, available copper, zinc, iron and manganese, soil organic matter and pH were measured. The GRA was used to calculate the grey relational degree and Kriging method was applied to map the spatial patterns of soil fertility quality. The distribution map of soil fertility quality showed that soil fertility quality was best in the southeast and well in the North, South, Northwest and East. The area of first-grade quality (I), second-grade quality (II) and third-grade quality (III) was 120.10, 734.37 and 184.53 km, respectively. The main factors influencing the spatial distribution of soil fertility quality were land use and soil management practices. The increasing trend of soil fertility quality might be attributed to the widespread practices of straw returning and organic manure applications.