黄河下游典型潮土区玉米地径流氮素流失特征  

Characteristics of Nitrogen Loss from Corn Field Surface Runoff in Typical Fluvo-aquic Soil Area of the Lower Reaches of the Yellow River

作　　者：张小磊[1] 裴颖春 夏长会 聂山权 王业宁 李春发[1] ZHANG Xiaolei;PEI Yingchun;XIA Zhanghui;NIE Shanquan;WANG Yening;LI Chunfa(Institute of Geography,Henan Academy of Sciences,Zhengzhou 450052,China;Henan Institute of Finance,Zhengzhou 450046,China;Henan Rongke Industrial Co.,Ltd.,Zhengzhou 450008,China)

机构地区：[1]河南省科学院地理研究所,郑州450052 [2]河南财政金融学院,郑州450046 [3]河南融科实业有限公司,郑州450008

出　　处：《水土保持研究》2023年第5期113-121,共9页Research of Soil and Water Conservation

基　　金：河南省科技发展计划项目(202102310599,222400410344);河南省高等学校重点科研计划项目(21B910001);河南省科学院人才队伍建设专项(200401003);河南省科学院科研开发专项(220601029)。

摘　　要：[目的]揭示自然降雨过程中黄河下游潮土区农田氮素随地表径流的流失特征,为地表径流水质预测及农业面源污染防控提供参考。[方法]采用定位试验的方法,在黄河下游典型潮土区进行夏季不同降雨条件下玉米地径流水质的连续监测,并分析了径流中TN(总氮)、DN(溶解态氮)、NN(硝态氮)和AN(铵态氮)的浓度变化过程、流失水平与强度及其影响因素。[结果](1)不同形态氮素浓度的峰值均出现在径流过程的前期,之后随降雨的持续,浓度曲线整体上呈下降的变化趋势;(2)径流中TN,DN,NN的EMC(次降雨事件污染物平均浓度)均超过或接近地表水Ⅴ类水质标准(2.00 mg/L),其中TN的EMC随降雨强度的增大依次是Ⅴ类水质标准的1.75,1.72,1.91,2.01倍,表明研究区域已存在明显的氮素污染风险;(3)径流中TN的流失以DN为主,而NN又以DN为流失主体,二者的EMC贡献率分别为56.75%~80.99%和72.78%~81.39%,并且在中、小降雨条件下贡献率更大;(4)TN,DN,NN,AN的流失强度和流失率均随降雨强度的增大而增大,各形态氮素流失强度和流失率的平均值分别为366.06,227.38,170.17,35.47 g/hm^(2)和39.55,24.30,18.07,7.46 g/(h·hm^(2));(5)Pearson相关分析结果显示:径流量和TSS(悬浮物)对AN浓度的影响较小,但对TN,DN,NN浓度的影响却十分明显;其中,中、小降雨条件下TN,DN,NN浓度与径流量之间均存在显著的正相关关系(p<0.05),且在小雨条件下相关性更为显著(p<0.01);大、暴雨条件下,TN浓度受到径流量和TSS的双重影响(p<0.05),且降雨强度越大,影响越强烈,但二者对DN,NN浓度的影响却并未达到显著水平。[结论]黄河下游潮土区夏季玉米地径流中各形态氮素的流失特征存在明显差异,可根据降雨强度的大小采取适宜的氮素流失防控策略,且控制径流并减少水土流失对提高氮素流失防治效率具有十分重要的意义。[Objective]The aim of this study is to explore the characteristics of nitrogen loss from corn field surface runoff in the fluvo-aquic soil area of the lower reaches of the Yellow River during the natural rainfall,and to provide reference for predicting surface runoff quality and preventing agricultural non-point source pollution.[Methods]Based on the method of positioning test,the continuous monitoring of dryland surface runoff quality under different rainfall conditions in summer was carried out.The concentration change process,loss level,intensity and influencing factors of TN(total nitrogen),DN(dissolved nitrogen),NN(nitrate nitrogen)and AN(ammonium nitrogen)in runoff were analyzed.[Results]The peak values of different forms of nitrogen concentration appeared in the early stage of runoff process,and then the concentration curve showed a downward trend with the continuation of rainfall.The EMC(event mean concentration)of TN,DN and NN in runoff exceeded or approached the class V water quality standard of China's surface water(2.00 mg/L).With the increase of rainfall intensity,the EMC of TN were 1.75,1.72,1.91 and 2.01 times higher than that of the class V water quality standard,respectively,indicating that there was an obvious risk of non-point source nitrogen pollution in the study area.The loss of TN in runoff was mainly DN,and NN was the main loss of DN.Their EMC contribution rates were 56.75%~80.99%and 72.78%~81.39%,respectively,but the rates were seemed greater under the medium and small rainfall conditions.The loss intensities and loss rates of TN,DN,NN,AN both increased with the increase of rainfall intensity,and their average values of every rainfall were 366.06,227.38,170.17,35.47 g/hm^(2) and 39.55,24.30,18.07,7.46 g/(h·hm^(2)),respectively.Pearson correlation analysis showed that runoff and TSS(suspended solids)had little effect on the concentration of AN,but had a very obvious effect on the concentrations of TN,DN and NN,and there was a significant positive correlation between TN,DN,NN concentration

关 键 词：氮素流失 面源污染 潮土区 径流 黄河下游 

分 类 号：S157.1[农业科学—土壤学]