农田土壤中氮的环境指标研究  

Environmental Indicator of Soil Nitrogen in Farmland

作　　者：田艳[1] 马友华[1] 胡宏祥[1] 吴蔚君 徐云连 赵学敏[1] 龚娟[1] Awais Shakoor Tian Yan Ma Youhua Hu Hongxiang Wu Weijun Xu Yunlian Zhao Xuemin Gong Juan Awais Shakoor(College of Resources and Environment, Anhui Agricultural University, Hefei 23003)

机构地区：[1]安徽农业大学资源与环境学院,合肥230036

出　　处：《中国农学通报》2017年第7期142-147,共6页Chinese Agricultural Science Bulletin

基　　金：国家科技支撑计划“南方平原稻作农区农业面源污染防控技术集成与示范”(2012BAD15B03);公益性行业(农业)科研专项“南方湿润平原区农业面源污染监测与氮、磷化肥投入阈值研究”(201003014)

摘　　要：氮肥的大量不合理施用使农田氮素成了农业面源污染的重要因子,然而关于农田氮素对环境污染的标准并没有系统的介绍。笔者分别从农田土壤氮素盈余、农田径流总氮、铵态氮、硝态氮等方面着手,介绍农田土壤中氮对环境产生的影响。土壤中氮素富集会加大农田土壤氮流失至水体的风险和数量。农田生态系统中氮素通过氨挥发、地表径流、下渗淋失等进入到环境,其盈余主要以气态、可溶态等形态对环境造成污染。综述国内外相关研究得到:农田径流损失的氮以可溶态为主,其中水稻田面水氮浓度超过30 mg/L会促使土壤矿质态氮部分释放,增加土壤溶液中矿质态氮含量,增加农田土壤氮流失风险;土壤无机N含量达到60 mg/kg时能满足作物的正常生长,超过此值,N素流失风险增加,多余的土壤NO3-N将会引起较大的环境风险。化肥使用量控制在150~180 kg/(hm^2·a)之内,可以有效控制化肥氮的损失污染。土壤氮素盈余、农田径流总氮、铵态氮、硝态氮等可作为农田土壤中氮的环境指标。Unreasonable application of fertilizer makes farmland nitrogen an important factor of agriculturalnon- point source pollution, while there is no systematic introduction on the criteria of farmland nitrogenpollution on environment. The authors introduced farmland nitrogen pollution on environment from the aspectsof soil nitrogen surplus, agricultural runoff TN, ammonium nitrogen and nitrate nitrogen. It found that theaccumulation of nitrogen in farmland could increase the quantity and risk of nitrogen running off to water.Farmland nitrogen flowed to the environment through ammonia volatilization, surface runoff and leaching loss,its surplus polluted the environment mainly in the forms of gaseous and liquid. Domestic and foreign researchresults showed that： farmland runoff nitrogen was mainly in soluble form. When nitrogen concentration inpaddy field surface water was more than 30 mg/L, it would promote the release of mineral nitrogen in soil,increase the content of mineral nitrogen in soil solution and the risk of nitrogen loss in farmland soil. Theconcentration of inorganic N in soil reached about 60 mg/kg could meet the need of normal growth of crops. If theconcentration exceeded this value, the risk of N loss increased, and the superfluous soil NO3-N would cause agreater environmental risk. When the fertilizer application amount was controlled between 150-180 kg/（hm^2·a）,the pollution caused by the loss of nitrogen fertilizer could be controlled effectively. Therefore, soil nitrogensurplus, agricultural runoff TN, ammonium and nitrate nitrogen could be used as the environmental indicatorsof farmland nitrogen.

关 键 词：农田 土壤氮 环境指标 氮素盈余 总氮 铵态氮 硝态氮 

分 类 号：S153[农业科学—土壤学]