Expanding of karst rocky desertification (RD) area in southwestern China isstrangling the sustainable development of local agricultural economy. It isimportant to evaluate the soil fertility at RD regions for the sustainablemanagement of karst lands. The changes in 19 different soilfertility-related variables along a gradient of karst rocky desertificationwere investigated in five different counties belonging to the central Hunanprovince in China. We used principal component analysis method to calculatethe soil data matrix and obtained a standardized integrate soil fertility(ISF) indicator to reflect RD grades. The results showed that the successionof RD had different impacts on soil fertility indicators. The changing trendof total organic carbon (TOC), total nitrogen (TN), available phosphorus, microbial biomass carbon (MBC), and microbial biomass nitrogen (MBN)was potential RD (PRD) > light RD (LRD) > moderate RD(MRD) > intensive RD (IRD), whereas the changing trend of otherindicators was not entirely consistent with the succession of RD. Thedegradation trend of ISF was basically parallel to the aggravation of RD,and the strength of ISF mean values were in the order of PRD >LRD > MRD > IRD. The TOC, MBC, and MBN could beregarded as the key indicators to evaluate the soil fertility.
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