【摘要】 基于巢湖沿岸坡耕地水土和养分流失监测的定位试验,于2014—2015年连续2a进行观测,研究小麦—芝麻模式下,植物篱（黄花菜）（PH）、植物篱+秸秆覆盖（PHS）和等高垄作（CR）3种农艺措施对水土和径流氮输出的控制效果。结果表明,植物篱、植物篱+秸秆覆盖和等高垄作能有效减少地表径流量和土壤流失量,3种农艺措施的降低效果依次为PHS>PH>CR。与CK（当地常规耕作）相比,PH、PHS和CR处理平均分别减少24.5%,36.5%和19.7%的径流流失和31.0%,45.6%和25.4%的土壤流失,表现出显著的水土保持作用,且减沙效果大于减流效果。3种农艺措施显著降低了径流液颗粒态氮（PN）的浓度,提高了溶解态总氮（DTN）、硝态氮（NO^-₃—N）和溶解态有机氮（DON）的浓度,但对总氮（TN）和铵态氮（NH⁺₄—N）浓度无显著影响。CK处理径流液中PN和DTN所占TN的比例基本相当,而在其3种农艺措施下,DTN是N随着径流迁移的主要形态。在DTN中,NO^-₃—N占较大比例,DON次之,NH⁺₄—N所占比例最小。CK处理N随地表径流平均年度累积流失量为9.35kg/hm²,占当年施N量的2.83%。与CK相比,PH、PHS和CR处理的N素年度累积流失量平均分别降低了28.3%,40.7%和21.2%,其对N素输出的控制效应主要是通过减流减沙来实现的。该研究可为巢湖流域坡耕地水土流失和面源污染防治提供科学依据。更多还原

【Abstract】 In order to test the efficiency of 3agronomic measures on reducing runoff,sediment and nutrient losses,a 2-year field runoff plot experiment was carried out in a sloping cropland of sesame-winter wheat rotation system around Chaohu Lake.4treatments were applied:conventional tillage（CK）,plant hedgerow（PH）,plant hedgerow with straw mulching（PHS）and contour ridge tillage（CR）.The results in 2014-2015 showed that plant hedgerow,plant hedgerow with straw mulching and contour ridge tillage could significantly limit soil and water losses and the effects listed in the order of PHS>PH>CT.Compared with CK,PH,PHS and CR decreased runoff amount by 24.5%,36.5%and 19.7%,respectively,and decreased sediment loss by 31.0%,45.6%and 25.4%,respectively,implying the significant effects of the 3agronomic measures on soil and water conservation,especially for sediment reduction.The 3agronomic measures significantly reducedthe PN concentration in runoff,while increased the concentrations of DTN,NO₃^--N,and DON,and had no obvious influence on the TN and NH₄⁺-N concentrations.The proportions of DTN and PN to TN were almost the same in CK treatment,while DTN was the predominant form of N transported via runoffin the treatments of PH,PHS and CR.Nitrate nitrogen（NO^-₃-N）was the major form of DTN in surface runoff,followed by dissolved organic nitrogen（DON）,and the proportion of ammonium（NH⁺₄-N）was very low.The annual nitrogen loss in runoff from sloping cropland in CK treatment was 9.35kg/hm²,which accounted for 2.83%of the nitrogen fertilizer application amount.Compared to the CK treatment,PH,PHS and CR treatments decreased annual nitrogen loss by 28.3%,40.7% and 21.2%%,respectively.Nitrogen loss was mainly decreased through the runoff and sediment reduction.This study could provide scientific basis for soil and water conservation,and regulation of non-point source pollution of sloping cropland in the Chaohu Lake region.更多还原