【摘要】 以浙江德清县排溪冲小流域生态系统为实例 ,采用定位土芯 Eu示踪和无界径流小区法研究了流域内坡地不同利用方式对土壤磷素流失的影响 ,结果表明 :( 1 )坡地不同利用方式磷素流失差异明显 ,流失最严重的是竹园 ,其次是旱地作物和新建果园 ,再次是幼龄茶园 ,林地和未开发利用的荒草地磷素的流失较轻 ;( 2 )泥沙结合态磷 ( Particulate phospho-rus,PP)随泥沙迁移流失是红壤坡地磷素流的主要形式 ,6种利用方式中 ,PP流失量占总磷流失量的平均值为 78.0 7%。但土地利用方式不同有差异 ,荒草地、林地和幼龄茶园流失的磷素中可溶性磷 ( Dissolved phosphorus,DP)的比重较大 ,分别为 3 5.2 9%、3 1 .4 9%和 2 7.65% ;( 3 )竹园、旱地作物和新开果园磷素流失严重的主要原因是农事活动和雨季相吻合 ,因而如何调整农事活动时间是减轻坡地磷素流失的关键。更多还原

【Abstract】 The study was conducted in a Paixichong micro watershed ecosystem of Deqing County,Zhejiang Province.The results obtained showed as follows:(1)Phosphorus loss varied obviously in different land use patterns.The order of phosphorus loss was bamboo field>upland field>newly exploited orchard>early tea plantation>China fir forest>waste grassland.(2)Particulate phosphorus(PP)was the major form of phosphorus loss with the run off.The average of PP in total phosphorus (TP)was 78 07% but varied with land use patterns.Dissolved phosphorus(DP)in total phosphorus(TP)in waste grassland,forested land and early tea plantation were 35.29%,31.49% and 27.65%,respectively,which were higher than other land use patterns.(3)The phosphorus loss seriously occurred in bamboo field,upland field and newly exploited orchard was attributed to the consistency of agricultural activities during the rainy season.更多还原