太湖流域旱地农业区氮素流失特征研究

了解水文过程对研究径流污染物的输出规律及控制农业非点源污染有重要意义。以张家港海芸枇杷林试验区为依托,监测自然降雨条件下研究区出口径流和地下水中的氮素浓度,研究了太湖流域典型旱地总氮(TN)、硝态氮(NO-3-N)、铵态氮(NH+4-N)流失的特征。结果表明,硝态氮是氮素流失的主要形式,占氮流失总量的90.1%;径流初期氮素浓度迅速升高,之后随径流增大逐渐降低,径流退水阶段壤中流携带土壤中硝态氮补给地表流,氮素浓度回升;氮素输出浓度随降雨强度的增强而升高。

Study on the Law of Nitrogen Loss in Non-irrigated Farmland of Taihu Basin

The study of hydrological processes is of great importance to investigate the law of runoff contaminant and protect agricultural non-point source pollution. Taking test region of Haiyunpibalin in Zhangjiagang City for an example, we monitored the nitrogen concentration of ground water and runoff outlet under the conditions of rainfall. And then the law of nitrogen loss in Taihu dry land are analyzed, which includes total nitrogen (TN), nitrate (NO-3-N) and ammonium nitrogen (NH+4-N). The results show that the nitrogen mainly exists in the form of nitrate which accounts for 90.1% of the nitrogen; at the beginning of runoff generation, the nitrogen concentration increased sharply, but with the runoff increasing the nitrogen concentration decreased; in the recession process of the surface runoff, the soil water carrying the nitrate recharges the runoff which brings up the nitrogen concentration; precipitation intensity impacts the nitrogen process; the concentrations of TN, NH+4-N, and NO-3-N increase as the rainfall intensity increase.