紫色土旱坡地氮流失通量对减肥配施秸秆的响应  

Response of Nitrogen Loss Flux in Purple Soil Sloping Field to Reduced Fertilizer and Combining Straw

作　　者：熊子怡 王子芳[1] 龙翼[2] 严冬春[2] 徐国鑫 高明[1] XIONG Zi-yi;WANG Zi-fang;LONG Yi;YAN Dong-chun;XU Guo-xin;GAO Ming(College of Resources and Environment,Southwest University,Chongqing 400715,China;Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610041,China)

机构地区：[1]西南大学资源环境学院,重庆400715 [2]中国科学院水利部成都山地灾害与环境研究所,成都610041

出　　处：《环境科学》2020年第4期1930-1940,共11页Environmental Science

基　　金：国家重点研发计划项目(2017YFD0800101);重庆市技术创新与应用专项(cstc2018jszx-zdyfxmX0014)。

摘　　要：紫色土旱坡地被认为是三峡库区泥沙和面源污染的主要来源地,加强对紫色土旱坡地壤中流和地表径流中氮流失特征的研究,对防控三峡库区的面源污染有重要的现实意义.依托中科院成都山地所忠县石宝寨试验站的紫色土旱坡地定位径流小区,设置不施肥(CK)、常规施肥(T1)、优化施肥(T2)和减肥配施秸秆(T3)这4种不同的处理,通过监测在油菜-玉米轮作制度下紫色土旱坡地壤中流和地表径流的流失通量、各次径流不同氮形态的流失浓度和流失通量,研究紫色土旱坡地氮流失通量对减肥配施秸秆的响应.结果表明,壤中流径流量占总径流量的比例达到60.14%~88.56%,壤中流氮流失通量占全氮流失通量的72.88%~92.35%.铵态氮主要通过地表径流的方式流失,硝态氮主要通过壤中流的方式流失且是氮流失的主要形态.不同处理的铵态氮和硝态氮流失通量均呈现出T1>T2>T3>CK,T3处理的氮流失通量为20.07 kg·(hm^2·a)^-1,较T1和T2分别下降了43.59%和39.55%.减肥配施秸秆显著降低了紫色土旱坡地铵态氮、硝态氮和全氮的流失通量,对紫色土旱坡地雨季径流中氮流失有显著的消减效应.The purple soil sloping field is considered as the main source of sediment and non-point source pollution in the Three Gorges Reservoir area.To prevent and control the non-point source pollution,it is indispensable to explore the characteristics of nitrogen loss in the overland flow and interflow of purple soil sloping field in Three Gorges Reservoir area.The purple soil sloping runoff plots,located in the Shibaozhai Experimental Station of Chengdu Institute of Chinese Academy of Sciences in Zhongxian County,Chongqing,were studied.The experiment included no fertilization treatment(CK),traditional fertilization treatment(T1),amended fertilization treatment(T2),and reduced fertilizer with straw treatment(T3).According to the data of volume of the interflow and runoff and the leach concentration and flux of nitrogen forms under rapeseed-maize rotation system,the response of nitrogen leaching flux to reduce fertilizer with straw application can be definite in purple soil sloping plots.The results show that the ratio of interflow to total runoff is 60.14%-88.56%,and the flux of nitrogen leaching in the interflow accounts for 72.88%-92.35%of total nitrogen loss flux.Ammonium was mainly leached by the overland flow.In addition,nitrate was mainly leached by the interflow and was the main form of nitrogen leaching.The fluxes of ammonium and nitrate under different treatments followed the order T1>T2>T3>CK.The total nitrogen flux of T3 was 20.07 kg·(hm^2·a)^-1,which was 43.59%and 39.55%lower than that of T1 and T2,respectively.The reduced fertilizer with straw application significantly decreased the leaching flux of ammonium,nitrate,and total nitrogen,and weakened the effect on runoff nitrogen leaching in the purple soil sloping plots.

关 键 词：紫色土旱坡地 面源污染 地表径流 壤中流 秸秆 

分 类 号：X171[环境科学与工程—环境科学]