巢湖典型地质富磷小流域表土磷分布特征

DISTRIBUTION CHARACTERISTICS OF PHOSPHORUS IN SURFACE SOILS OF TYPICAL SMALL WATERSHED IN CHAOHU LAKE

巢湖流域富磷地质层磷的流失对水体富营养的影响不可忽视,为了解富磷岩层裸露区域磷的分布特征,在巢湖东北部采集125个土样,采用改进的Hedley化学提取法测得各磷形态含量。结果表明:土壤TP平均含量为561.94 mg/kg,富磷矿地最高,达1 119.88 mg/kg,远超其他功能区的平均含量;各形态磷呈明显空间变异,北部含量较低,含量高的地区主要在东南部农业地区及西部山区,富磷岩层周边的土壤各形态磷与总磷的含量较高;生物有效磷含量平均可达135.44 mg/kg,各形态磷的空间分布受土地利用类型影响较大,对巢湖磷污染影响不能忽视。

The effect of phosphorus loss on eutrophication in rich phosphate rock of Chaohu Lake could not be neglected. To find out the distribution of phosphorus（P） in esposed area of phosphorus,125 samples were collected from northeastern of Chaohu Lake,the contents of phosphorus species were measured by a modified Hedley phosphorus fractionation. The results showed that the average content of TP was 561. 94 mg/kg,and the average content of TP in the phosphate soil was up to1 119. 88 mg/kg,far more than the other functional areas. Generally,the phosphorus in the study area showed obvious spatial variation,the low-P fields appeared in the northern study area,and the high-P fields appeared in the southeast agricultural region and western mountains,the contents of phosphorus and TP in the soils around the rich phosphate rock were higher. The content of biological effective phosphorus was 135. 44 mg/kg..The spatial variability of phosphorus species contents were greatly affected by the mode of urban land-use type,and the influence on the phosphorus pollution in Chaohu Lake could not be ignored.