摘要
自 8 0年代初以来 ,太湖流域农田土壤 ( 0～ 15cm)磷素水平有了较大的提高 ,全磷平均提高了 0 .1g/ kg左右 ,速效磷含量大多增加了 4～ 5mg/ kg;种植经济作物的土壤由于磷盈余量大 ,磷素水平提高幅度更大 ;缺磷土壤的面积已经大大减少。与此同时 ,土壤磷素水平的提高增加了土壤磷向水体流失的风险。不同类型土壤的固磷能力有着较大的差别 ,而区内某些固磷能力较低的土壤常常被用来种植经济作物 ,过量的磷素投入增加了土壤磷向水体流失的风险和流失量。
Results of the sampling of representative soils in the Taihu Lake watershed between 1982 and 1999 show that decades of P fertilization at rates exceeding the removal rates by crops has resulted in widespread accumulation of P in agricultural soils. The increase in Total P and Olsen P is 0.1 g/kg on average and 4-5 mg/kg for most soils, respectively. Such a surplus has brought up the P level by a large margin in the soils of lands grown with cash crops, and the area of soils deficient in P has largely decreased. The increase in soil P, however, also enlarges the risk of P loss from soil to surface water. Soils differ from type to type in P adsorption capacity. Moreover, in this region, soils with low P adsorption capacity are often used to grow cash crops. As a result, excess P input increases the risk and the amount of soil P loss to water bodies.
出处
《农村生态环境》
CSSCI
CSCD
2000年第4期24-27,共4页
Rural Eco-Environment
基金
中国科学院"九五"重大项目(KZ951-A1-301)
中国科学院特别支持项目(KZ95T-04-01)共同资助
关键词
太湖流域
土壤磷素状况
水环境质量
phosphorus
soil
Taihu Lake
water environment quality
watershed
