杨麦间作系统对太湖流域土壤氮流失的削减效应  

Effects of poplar-wheat intercropping system on soil nitrogen loss in Taihu Basin

作　　者：褚军[1,2] 薛建辉[1,2] 金梅娟[3] 吴永波[1,2] 侍昊[4] 徐艺倩 

机构地区：[1]南京林业大学生物与环境学院,江苏省林业生态工程重点实验室,南京210037 [2]南京林业大学南方现代林业协同创新中心,南京210037 [3]苏州市农业科学院/江苏太湖地区农业科学研究所,苏州215155 [4]江苏省环境监测中心,南京210036

出　　处：《农业工程学报》2015年第16期167-177,共11页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家林业公益性行业科研专项项目(201104002);国家林业局“948”项目(2014-4-24);江苏省高校自然科学研究重大项目(12KJA180003);江苏高校生物学优势学科建设工程项目(2014-PAPD)

摘　　要：过量施肥造成的农业面源污染已成为太湖水质下降及富营养化的主要原因之一。该试验在距离太湖湖岸带约1 km的小麦种植区对2种杨麦间作密度（其株距均为2 m,行距分别为5 m（AS1）和15 m（AS2））削减土壤氮流失效应进行研究。结果表明：杨树林冠层对降雨的截留主要集中于4-10月,AS1间作密度下林冠层对降雨的截留幅度达8.6%~44.5%。由于林冠层对降雨的再分配作用导致的径流量AS1R（去除枯落物：Remove litter）处理显著低于AS2R和MSL0（单作麦地中未铺设枯落物处理）处理（P〈0.05）。在整个小麦生长季,AS1S（有枯落物覆盖：Save litter）处理径流中TN、NO3--N平均浓度、流失量均显著低于MSL0（P〈0.05）。60 cm土层AS1S平均淋溶水量、TN、NO3--N平均浓度和流失量与AS2S、MSL0之间均存在显著差异（P〈0.05）。在杨树落叶期,AS1系统有枯落物覆盖下地表径流量、TN、NO3--N平均浓度和流失量均显著低于无枯落物处理（P〈0.05）。而AS2系统有无枯落物覆盖之间差异则不显著（P〉0.05）。在去除冠层及枯落物影响后,AS1R处理60 cm土层淋溶水量、TN和NO3--N淋溶流失量均显著低于20cm土层（P〈0.05）,而MSL0系统下20、40、60 cm之间差异均不显著（P〉0.05）。由此可见,株行距为2 m×5 m的杨麦间作密度对地表径流、淋溶及氮流失的削减效应更显著。Agricultural non-point pollution caused by the overuse of fertilizer in farmland has become one of the main factors for water quality deterioration and eutrophication in Taihu Lake. In order to select suitable agroforestry intercropping system to control soil nitrogen loss in Taihu Lake basin, a study was conducted at a distance of 1 km away from the lakeshore to find out how poplar-wheat intercropping system with 2 kinds of densities （AS1： poplar spacing 2 mx5 m; and AS2： poplar spacing 2 mx 15 m） affected the amount of surface runoff, leaching and soil nitrogen loss. The interception of rainfall by the poplar canopy was mainly concentrated from April to October and ranged from 8.6% to 44.5%. The control effects of canopy layer on sprinkle and moderate rain （〈1.0 mm/h） were obvious, which were reduced by 47.7% on average. Rainfall interception by canopy was mainly related to the LAI （leaf area index）. The volume of rainfall difference between AS1 and MS （monoculture system） was only 0.8% during the defoliated period while the control effect of AS1 was raised to 6.4% during the growing period. Compared to AS2R （means removing litter） and MSL0 （monoculture of wheat without litter coverage）, the runoff amount of AS1R decreased by 9.1% and 11.2%, respectively. There was a significant difference between AS1R and AS2R/MSL0 （P〈0.05）, while the difference between AS2R and MSL0 was not significant （P〉0.05）. Compared to MS, the volume of surface runoff, leaching and soil nitrogen loss were all effectively controlled by the 2 poplar-wheat intercropping systems. The control effects were more significant under the higher intercropping density. There was no significant difference between the average runoff volume of AS1S （means saving litter） and AS2S/MSL0 during the whole growing period （P〉0.05）, while their average concentration and leaching amount of total nitrogen （TN） and NO3＂-N were both significantly lower than MSLo （/）〈0.05）. The average leaching water

关 键 词：土壤 氮 径流 杨树-小麦间作系统 淋溶 林冠层 枯落物 根系 

分 类 号：S792.11[农业科学—林木遗传育种] S512.1[农业科学—林学]