夏灌对内蒙古河套灌区土壤中磷元素迁移的影响

Impact of summer irrigation on phosphorus transportation in Hetao Agricultural Irrigation Area,Inner Mongolia

磷作为植物生长必需的元素之一,是引起水体富营养化的重要因素。通过对内蒙古河套灌区2008年夏灌前后农田灌、排水和地下水以及土壤中不同形态磷含量和土壤含水率的分析测定,借助SPSS13.0软件对监测结果进行统计分析,研究夏灌期间灌区土壤中磷元素的迁移规律及其影响因素。结果表明:夏灌后,土壤含水率仅表层有明显增加,且夏灌前后土壤含水率与土层深度显著相关(相关系数分别为0.751和0.770),土壤中有效磷含量和土壤含水率显著相关(Sig.为0.009);夏灌期间,不同土层深度处的磷元素含量差异显著,作物类型和种植方式对磷元素在土壤中的分布无显著影响;夏灌会造成土壤中磷元素向地下水迁移,且流失形态主要为可溶性磷。该文可为灌区科学合理的水肥管理以及控制磷流失提供依据。

Phosphorus,as one of the essential elements for crops,has direct contribution to water eutrophication.During summer irrigation in 2008,the soil moisture,phosphorus content of farmland soil,irrigation ditch water,drainage streams water,underground water and soil percolate were monitored,which resulted in phosphorus transportation analysis in Hetao agricultural irrigation area,Inner Mongolia.The data were also statistically analyzed by SPSS13.0 in order to find out the principal factors of phosphorus transportation.The results revealed that,only the soil moisture in topsoil were markedly increased after the summer irrigation,and the soil moisture before and after summer irrigation both significantly correlated with soil depth（Correlation coefficients were 0.751 and 0.770）.Meanwhile,available phosphorus（also called Olsen-P） concentration in soil significantly correlated with the soil moisture too（Sig.=0.009）.During the summer irrigation,the phosphorus concentration showed significant difference in different soil depth,but factors such as crop type and cropping pattern did not have notable impacts.After summer irrigation,phosphorus in soil transported to groundwater,mainly in the form of soluble phosphorus.The conclusions in this paper can be used to provide scientific reference on appropriate scheduling for efficient fertilization,irrigation,and controlling phosphorus loss.