Land use and climatic conditions control the soil organic carbon’s distribution in qufu and laixi, North China plain

Abstract

Understanding the factors controlling the distribution of soil organic carbon (SOC) is crucial to estimate SOC stocks and explore the optimal soil management for carbon sequestration and migrating climate change. Herein, we quantitively evaluated the influences of land use (farmland and wasteland), soil properties (pH, eight heavy metals, and seven minerals), and climatic conditions (temperature and precipitation) on the spatiotemporal variation of SOC in surface soils (0-20 cm) and soil columns (180 cm) in Qufu and Laixi, North China Plain. SOC concentrations in surface soils and soil columns were 1.84-27.4 and 1.82-9.33 g/kg, respectively. With ca. 64% of SOC stored in 20-180 cm layers and the dramatic increase rate of >70% for SOC in soil columns, SOC in subsoil showed its more considerable significance than that in the surface soil. Land use and climatic conditions contributed avg. 45.6 and 41.5%, respectively, to SOC in surface soils and 54.3 and 26.6%, respectively, in soil columns. Our results suggest the dominant influences of land use and climatic conditions on the SOC distribution and reemphasize the considerable importance of SOC in subsoil because of the high storage and storage potential of SOC in subsoil.