Objective Different land use types have significant influences on the decomposition capacity of soil microorganisms and nutrient cycling, which changes soil carbon (C), nitrogen (N) and phosphorus(P) contents, storages and stoichiometric ratio. However, there were many studies on the response of soil C, N and P contents to different land use types by stoichiometric ratio, but the studies on soil C, N and P storages under different land use types in Chonglingshui Basin were not clear.

Method In order to further understand soil C, N and P contents, storages and stoichiometric characteristics under different land use types, three land use types (forest land, grassland and cultivated land) in Chonglingshui Basin were selected in this study, and the soil C, N and P contents, storages and stoichiometric characteristics under different soil layers and three land use types in the basin were analyzed.

Result The results showed that soil depth significantly changed soil organic C content, total N content, C∶N, C∶P, C storage and N storage. The land use types of woodland, grassland and cultivated land had significant effects on soil physicochemical properties and C∶P, N∶P and total P storage, showing the same rule in soil C, N and P contents and storages, and a decreasing trend with the increase of soil depth on the whole. The average soil organic C content in forest, grassland and cultivated land increased successively, but there was no significant difference between the three land use types with the amounts of 8.99 g kg⁻¹, 9.35 g kg⁻¹ and 9.90 g kg⁻¹, respectively. Soil total N content was the highest in cultivated land, followed by forest land, and the lowest in grassland (1.34 g kg⁻¹, 1.29 g kg⁻¹ and 1.27 g kg⁻¹, respectively). The contents of total P in cultivated land, forest land and grassland were 0.65 g kg⁻¹, 0.34 g kg⁻¹ and 0.31 g kg⁻¹, respectively. In 0 ~ 60 cm layer, soil C∶P and N∶P were significantly different (P < 0.05). The soil N∶P ratio was lower than 14, and the plant growth process was limited by N.

Conclusion Soil layer affects soil C, N and P contents and storages, and land use type affected soil physical and chemical properties. The results provides certain theoretical support for regulating nutrient cycling in typical river basins in subtropical karst areas and developing agricultural and forestry production.