[Distribution characteristic of soil organic carbon pool in the plow layer of sloping farmland with different cultivation years in black soil region].

Tillage and erosion simultaneously cause soil movement from the top-slope position to the foot-slope position in a sloping farmland, with consequences on variation of soil organic carbon (SOC) content as well as its stability mechanism. To identify the accumulation-loss characteristics of organic carbon pool (OCP) of black soil under long-term cultivation, the distribution characteristics of different OCPs (free unprotected, physical protection, chemical protection, biochemical protection) of sloping farmland with different years of cultivation were quantified by Stewart physical-chemical fractionation method. The results showed that long-term cultivation and associated erosion resulted in significant accumulation of SOC in the foot-slope deposition area.