蔬菜地土壤磷饱和度及其对磷释放和水质的影响  

Phosphorus saturation degree of soils on vegetable farms and its effects on soil phosphorus release potential and water quality

作　　者：章明奎[1] 周翠[1] 方利平[1] 

机构地区：[1]浙江大学环境与资源学院资源科学系,浙江杭州310029

出　　处：《植物营养与肥料学报》2006年第4期544-548,共5页Journal of Plant Nutrition and Fertilizers

基　　金：浙江省科技计划项目(2004C33061)资助

摘　　要：为了解蔬菜地土壤磷素的积累对水环境的影响,我们在浙江省选择了33个代表性蔬菜地,采集和分析了土壤、地表水和地下水样的磷素状况,从土壤磷饱和度的角度,研究了浙江省主要蔬菜土壤磷积累状况及其对地表和地下水水质和土壤磷释放潜力的影响。结果表明,半透膜渗析法测得的磷释放量与土壤磷积累呈正相关,磷释放量随土壤磷饱和度的提高而增加。蔬菜地土壤磷饱和度的增加可显著提高地表水体和地下水中磷的浓度,当土壤磷饱和度小于25%左右时,水体中磷浓度随土壤磷饱和度增加较为缓慢;但当磷饱和度大于25%时,水体中磷浓度随土壤磷饱和度提高迅速上升。地表水中磷浓度主要与表层土壤磷饱和度有关;地下水中磷浓度主要受深层土壤磷饱和度的影响,与表层土壤磷饱和度的相关性较小。土壤磷饱和度可很好地表征土壤磷释放和对环境的潜在影响。Phosphorus losses from agricultural soils to water can pose a threat to water quality. The concern over P with respect to water quality is its stimulation on algae and other aquatic plant growth. Phosphorus inputs to agricultural soils that are regularly fertilized with mineral P can exceed crop requirement. This over-supplied P often results in excessive P accumulation in the soil, and such soils represent a potential diffuse source of pollution as P for the eutrophication of surface waters. Little information is available on the release intensity of P to water from vegetable soils and its relation to the P saturation degree in the soils. In this study, 33 surface soil samples and 17 soil profiles with a wide range of total P, and runoff and groundwater samples were collected from various vegetable fields in Zhejiang province. Results showed that long-term over application of P could elevate P saturation degree, increased P release potential from the soils. Phosphorus release intensity measured by means of dialysis was positively correlated with soil P accumulation, and increased significantly with P saturation degree of the soils. Increased soil P saturation degree could increase P concentrations in surface waters and groundwater. The P concentration in surface runoff increased slowly with increasing P saturation degree when P saturation degree was below 25 %, but it increased rapidly when P saturation degree was over 25 %. The P concentration in surface waters was mainly correlated with P saturation degree of the surface soils, whereas the P concentration in groundwater was controlled by P saturation degree of subsurface soils. These results indicated that soil P saturation degree could efficiently characterize soil P release potential and its impaction on the environments.

关 键 词：蔬菜地 磷饱和度 磷释放 水质 

分 类 号：X52[环境科学与工程—环境工程]