【摘要】 环洞庭湖坡耕地氮磷流失是湖泊水体富营养化的重要原因.以环洞庭湖红壤坡耕地玉米为研究对象,通过田间小区试验,研究常规施肥(CK)、常规施肥+秸杆覆盖3 000 kg/hm~2(A)、常规施肥+秸杆覆盖6 000 kg/hm~2(B)、常规施肥+地膜覆盖(C)对玉米生长和面源氮磷流失的影响.结果表明,不同覆盖方式能够有效减少地表径流量和泥沙流失量,其中径流量较CK减少了18.7%～25.3%,而泥沙流失量减少了11.3%～24.5%.覆盖处理A、B、C氮总流失量分别降低33.6%、41.9%、48.3%;磷总流失量,覆盖处理A、C分别降低15.4%、21.6%,而覆盖处理B与CK相近.秸秆与地膜覆盖有利于玉米增产,秸秆与地膜覆盖不仅一定程度提高氮磷化肥肥效和肥料利用率,而且能减少农业面源污染.更多还原

【Abstract】 Nitrogen and phosphorus loss in slope farmland around Dongting Lake is an important reason for eutrophication of lake water.Taking corn on red soil slop around Dongting Lake as the object of the study,through field plot experiment,the effects of conventional fertilization(CK),conventional fertilization + straw mulching 3 000 kg/hm~2(A),conventional fertilization + straw mulching 6 000 kg/hm~2(B),conventional fertilization + plastic film mulching(C) on the growth of corn and the loss of nonpoint nitrogen and phosphorus were studied.The results showed that different mulching methods could effectively reduce surface runoff and sediment loss,of which the runoff was 18.7%～25.3% lower than CK while the sediment loss was 11.3%～24.5% lower.The total nitrogen loss of A,B and C was reduced by 33.6%,41.9% and 48.3% respectively.The total phosphorus loss was reduced by 15.4% and 21.6% respectively in the mulching treatment A and C,while the mulching treatment B was similar to CK.Straw and plastic mulching were beneficial to increase maize yield.Straw and plastic mulching could not only improve N,P fertilizer efficiency and fertilizer utilization rate,but also reduce agricultural nonpoint pollution.更多还原