Objective The study was conducted to explore the effect of terracing in low mountain sloping land on the distribution characteristics and availability of soil phosphorus in northern Guangdong.

Method The forest land (FL), dry land terrace(UT)and paddy terrace(PT)soils developed from granite in this area were selected as research objects, and the physicochemical properties, phosphorus content and availability of different soil layers in the soil profile were determined.

Result Compared with FL, available phosphorus and phosphorus activation coefficient(PAC)of UT and PT 0-20cm soil increased significantly, and PT soil had the highest value. Soil organic phosphorus(OP)and inorganic phosphorus(IP)of three land uses in the profile showed a C-shape trend, and those of topsoil were the highest. Compared with FL, UT and PT soils were dominated by IP, and Fe-P and O-P accounted for higher proportion. The proportion of O-P increased from 7.69%-13.58% to 22.97%-41.96%. The results of path analysis and redundancy analysis showed that OP was sensitive phosphorus for the availability of soil phosphorus in this area, and free iron and organic carbon were the key factors to drive the conversion of soil phosphorus components.

Conclusion The terracing in low mountain sloping land in northern Guangdong changed the distribution pattern of phosphorus in the soil profile and increased the availability of phosphorus and the proportion of soil ineffective phosphorus.