太湖地区水稻节水灌溉与氮素淋失

Water Saving Irrigation and Control of Nitrogen Leaching in Taihu Lake Region

通过田间试验探讨有效的农田氮素水体污染防治途径 .研究表明 ,节水灌溉 (湿润灌溉 )情况下渗漏水中总氮浓度、氮素渗漏量、氮素渗漏损失代价均随着施氮量的增加而增加 ,渗漏水中 3种形态的氮素 (硝态氮、铵态氮和有机氮 )以硝态氮为主 ,铵态氮和有机氮占的比例较低 ;和常规灌溉相比 ,相同施氮处理 ( 2 64.75kg/hm2 )采用节水灌溉时稻谷增产 4 .1% ,氮肥当季利用率提高 3%、氮素渗漏量下降 8.9kg/hm2 ,水稻节水灌溉是当前降低太湖地区水体氮素污染行之有效的重要措施之一 .

The purpose of this research is to find a feasible way of controlling farmland nitrogen pollution through field experiments. Results show that the concentration of total nitrogen in leaching water, the amount of nitrogen leached, and the cost of nitrogen leached increase with the increase of nitrogen fertilizer applied under the condition of water saving irrigation(moisture irrigation)in the paddy field. Nitrate N, is highest, ammonia N is mediate, and organic nitrogen is the lowest in the three nitrogen forms in leaching water. Compared with the data for conventional irrigation, the rice yield,and nitrogen utilization efficiency in the period of rice growth are 4.1% and 3% higher,and the nitrogen leached is 8.9 kg/hm 2 lower than for water saving irrigation. Water saving irrigation could be considered as one of the important and feasible measures to reduce nitrogen impact on the Taihu Lake.