RELATIONSHIP BETWEEN SOIL ENZYME ACTIVITY AND INORGANIC PHOSPHORUS FORMS IN HIGH PHOSPHORUS REGION OF XIANGXI RIVER WATERSHED

The release of nitrogen and phosphorus from upland is an important factor which leads to the eutrophication in aquatic ecosystems． The phosphate ores distributed in Xiangxi Ｒiver Watershed，west of Hubei，posed a serious impact on water quality of Xiangxi Ｒiver． The purposes of this study were to investigate the intrinsic relationship between soil enzyme activity and inorganic phosphorus ( IP) forms in the phosphorus-rich area of the Xiangxi Ｒiver watershed，and explore the feasibility of using soil enzyme system characterization of the magnitude of soil phosphorus pollution． Ｒesults showed that there was a significant relationship between soil enzyme activities and IP forms． The activities of catalase，sucrase and urease were significantly correlated to IP forms，while polyphenol oxidase and alkaline phosphatase activities were significantly and negatively correlated to IP forms． The activities of soil catalase，polyphenol oxidase，sucrase，urease and alkaline phosphatase showed different degrees of correlation with IP forms． The findings suggest that soil enzyme activity might be used as an indicator for the magnitude of soil phosphorus pollution in the phosphorus mineral region．