巢湖流域不同耕作和施肥方式下农田养分径流流失特征  

Characteristics of Nutrient Runoff Losses from Farmland Under Different Tillage and Fertilization Methods in Chaohu Lake Region

作　　者：王静[1,2] 郭熙盛[1,2] 王允青[1,2] 丁树文[3] 

机构地区：[1]安徽省农科院土壤肥料研究所,合肥230031 [2]安徽省养分循环与资源环境省级实验室,合肥230031 [3]华中农业大学资源与环境学院,武汉430070

出　　处：《水土保持学报》2012年第1期6-11,共6页Journal of Soil and Water Conservation

基　　金：国家科技支撑计划(2007BAD87B06);安徽省科技攻关计划(08010302160)

摘　　要：采用野外定位观测试验,研究巢湖流域不同耕作和施肥方式下农田养分径流流失特征,探索降低养分流失、提高湖区水质的有效耕作和施肥措施。2009-2010年结果表明,冬季麦田径流液总氮(TN)的浓度范围是2.12～4.34mg/L,溶解态氮(DN)约占TN的72%～92%,DN中又以硝态氮(NO3--N)为主,溶解态有机氮(DON)次之,铵态氮(NH4+-N)所占比例极小。径流液总磷(TP)浓度范围是0.095～0.360mg/L,颗粒态磷(PP)约占TP的51%～69%。DN和PP是农田氮磷径流流失的主要形态。长期的保护性耕作可提高径流液TN、DN、NO3--N、DON和DP的浓度,降低PN和PP的浓度,但对NH4+-N和TP浓度无明显影响;氮肥后移一定程度上易增加追肥后短期内降雨径流液各形态N的浓度,但可降低小麦整个生育期内径流液各形态P的浓度。在当地常规耕作条件下(处理CT),麦田TN和TP径流流失量分别为1.065,0.079kg/hm2,占当季施N量的0.71%,施P量的0.24%。与处理CT相比,处理CTS(常规+覆盖)、NFP(氮肥后移)和NTS+NFP(少免耕覆盖+氮肥后移)TN流失量分别减少了14%、21%和24%,TP流失量分别减少了20%、21%和24%。因此,保护性耕作和氮肥后移在保证小麦产量的前提下,可作为巢湖流域源头控制农田养分流失的主要措施。In order to explore the ways of reducing nutrient runoff losses and improving lake water quality by effective tillage and fertilization methods,a long-term field experiment to study the characteristics of nutrient runoff losses from farmland was conducted in Chaohu lake region.The results of winter wheat in 2009-2010 showed that,the total nitrogen（TN） concentration in runoff of winter wheat field was 2.12～4.34 mg/L,in which the dissolved nitrogen（DN） accounted for 72%～92%.Nitrate nitrogen（NO-3-N） was the major form of DN in surface runoff,followed by dissolved organic nitrogen（DON） and the proportion of ammonium（NH＋4-N） was very low.The concentration of total phosphorous（TP） in runoff ranged between 0.095～0.360 mg/L,in which the particulate phosphorous（PP） accounted for 51%～69%.DN as well as PP was the main form of N and P loss by runoff from farmland.The long-term conservation tillage increased the concentration of TN,DN,NO-3-N,DON and DP,reduced the concentration of PN and PP,and had no obvious influences on the NH＋4-N and TP concentration.Postponing N application could decrease the phosphorous concentration in the surface runoff,while probably increasing the nitrogen concentration after the several days of nitrogen fertilizer topdressing in some extent.The nitrogen and phosphorous runoff losses from winter wheat field in the conditions of conventional tillage were 1.065 kg/hm2 and 0.079 kg/hm2,occupying 0.71% and 0.24% in the applied N and P at the wheat cropping season,respectively.Compared with conventional tillage（CT）,the nitrogen loads in runoff of conventional tillage＋straw returning（CTS）,N fertilization postponed（NFP） and non-tillage straw returning＋N fertilization postponed（NTS＋NFP） declined by 14%,21% and 24%,as well as by 20%,21% and 24% for the phosphorous loads,respectively.Assuring the production of winter wheat,the conservation tillage and postponing N fertilization could be the major measures for the source control of the nitrogen and

关 键 词：保护性耕作 氮肥后移 氮 磷 径流损失 面源污染 

分 类 号：S157.4[农业科学—土壤学]