Soil geochemical characteristics and soil quality evaluation of agricultural land in the intermountain basin area in the upper reaches of Xin'an River

In order to evaluate the soil quality of agricultural land in the intermountain basin area in the upper reaches of Xin'an River, analyze the main factors affecting soil quality, and serve the local agricultural development and the reform of ecological protection compensation mechanism in Xin'an River basin, the soil quality in the study area was evaluated according to the method stipulated in the Specification of Land Quality Geochemical Assessment, and correlation analysis and principal component analysis were used to explore the source of each component in soil. The results show that: (1) The environmental grade of soil in most areas of the study area is risk-free, and the grade in carbonate and black rock series distribution areas in the northwestern of the study area is risk-controllable. The content of Cd element in soil is the main factor affecting the environmental grade. (2) The nutrient levels of soil in the study area were mainly medium, followed by rich and deficient soil, and the content of organic matter in soil was an important factor affecting the nutrient levels. (3) The main reason for the high content of Cd in soil in partial region is that was adsorbed by iron and manganese nodules and organic matter. (4) The soil quality in the study area is pretty good, which is suitable for agricultural production on the whole. According to the characteristics of large acid area, lack of highly-rich nutrient area and high Cd content in some areas in the soil of the study area, the soil can be further improved to increase the yield and quality of agricultural products.