Geochemical characteristics and its indicative significance of soil elements in key soil erosive areas of Changting County, Fujian Province

In view of element geochemical migration law during soil erosion, a geochemical investigation of land quality was carried out to ascertain the geochemical characteristics of soil elements and evaluate the abundance and deficiency of soil nutrients and the ecological risk of soil environment in the key soil erosive areas of Changting County, Fujian Province. Compared with the related background values of Fujian Province, the soil nutrients and contents of soil heavy metals in the key soil erosive areas of Changting County are relatively low, indicating risk-free soil environmental quality. The element contents of soils originated from different parent rocks show visible differences: the soil developed from the Lower and Middle Jurassic clastic rocks are characterized with element depletion, while the soil from metamorphic rocks are rich in elements. By comparing the differences of soil element contents in various degrees of soil erosive areas, it is found that with the aggravation of soil erosion, the nutrient elements including nitrogen, phosphorus and organic matter in the soil are significantly lost, and the heavy metal elements such as arsenic, cadmium and mercury are diffused with the evolution of erosion.