Geochemical Distribution Characteristics of Nitrogen, Phosphorus, and Potassium Elements in Soils, and a Soil-Fertility Evaluation for Chuxiong Prefecture, Central Yunnan

Abstract

To identify spatial characteristics of soil fertility in Chuxiong Prefecture, central Yunnan, soil contents of nitrogen (N), phosphorus (P), and potassium (K) are reported in a systematic geochemical investigation. Average concentrations of these elements throughout this region are 1.16 g/kg (N), 0.597 g/kg (P), and 17.853 g/kg (K). A comparison of element concentrations from the surface to deeper soils, and in rocks, suggests that N and P in surface soils mainly emigrate into them, and K mainly immigrates from them. Soils throughout Chuxiong Prefecture are mostly medium-fertile; only one-third of the area has rich soil. These findings provide a scientific basis on which nutrients, fertilization, and agricultural cultivation in Chuxiong Prefecture, and to highland agriculture in general, can be more rationally utilized or planned for development.