摘要
因坡地农业开发而产生的随径流迁移输出的磷素是面源污染的来源之一,对地下水环境造成潜在威胁。利用江西水土保持生态科技园内大型土壤渗漏装置,开展自然降雨条件下,红壤坡地百喜草覆盖、百喜草枯落物敷盖和裸露坡面等不同覆盖处理下,磷素随径流垂向分层输出特征研究。结果表明:1)随着土层深度的增加,随径流迁移总磷浓度大幅降低;可溶性磷占总磷的比例高且稳定,是磷素随径流输出的主要形式。2)在裸露、百喜草敷盖和百喜草覆盖3种处理小区,土壤总磷输出总量为裸露>敷盖>覆盖;3场暴雨条件下,覆盖小区对总磷和可溶性磷的总削减率分别为35%~92%和44%~96%,敷盖小区削减率分别为9%~86%和0~89%。3)裸露小区随地表径流流失的总磷比例可达90%以上;3种处理小区壤中流输出总磷质量分数都相对较小;覆盖和敷盖小区则以地下径流为主,其比例可达60%以上。研究结果可为坡地农业的水土流失和面源污染防治提供参考。
[Background]Phosphorus from the runoff migration is one of the sources of non-point source pollution because of slope agriculture development,which is also a potential threat to the groundwater environment.The most important reason of water eutrophication is the input of external phosphorus.The migration and output process of phosphorus from the soil of slopes to water is not only the focus of soil science research,but also one of the resource and environmental problems that needs to be solved urgently.[Methods] In Jiangxi Provincial Eco-Science Park of Soil and Water Conservation,Drainage Lysimeter was used to study the characteristics of phosphorus output through runoff from different layers under natural rainfall conditions in red soil slopes.Three 5×15 m plots with slope of 14° were established by three land cover treatments which were Paspalum notatum Flugge coverage,P.notatumFlugge litter mulching and bare land.There were four discharge outlets used to collect surface runoff,30 cm interflow,60 cm interflow and 105 cm underground runoff in each plot.Runoff samples were collected and analyzed for the content of phosphorus during the three natural rainfall events process in 2013 and2014.[Results]1） The total phosphorus（TP） concentration migrating through runoff decreased sharply with the increase of soil depth.The proportion of dissolved phosphorus（DP） to TP was high and stable,which was the main form of phosphorus output through runoff.2） Output amounts of TP through runoff in three treatments decreased gradually from bare land,litter mulching to grass coverage.Under the three storm conditions,the total reduction rate of TP and DP was 35%-92% and 44%-96% respectively by grass coverage treatment,and 9%-86% and 0-89% respectively by litter mulching treatment.3）The proportion of TP through the surface runoff reached more than 90%.The proportion of TP through interflow was relatively small of the three treatments.The proportion of TP through underground runoff which reached more than 60% was the m
出处
《中国水土保持科学》
CSCD
北大核心
2017年第4期68-77,共10页
Science of Soil and Water Conservation
基金
水利部鄱阳湖水资源水生态环境研究中心开放基金项目"鄱阳湖流域坡耕地径流泥沙分配及污染物迁移特征"(ZXKT201501)
"外源性有机碳对红砂岩侵蚀劣地土壤改良研究"(ZXKT201502)
国家自然科学基金"红壤坡地水沙分配及其与氮磷的伴生迁移特征"(41461060)
江西省青年科学基金"鄱阳湖区坡耕地侵蚀泥沙中氮磷的赋存形态及解吸特征"(20161BAB216148)
关键词
红壤坡地
磷素输出
不同覆盖
分层
自然降雨
red soil slopes
phosphorus output
different land cover treatments
different soil layers
natural rainfall
