太湖流域典型稻-麦轮作农田区氮素流失过程研究  

Study on Nitrogen Loss in Rice-wheat Rotation Farmland in Taihu Basin

作　　者：范宏翔 徐力刚[1] 赵旭[2] 胡岳峰[1] 

机构地区：[1]中国科学院南京地理与湖泊研究所流域地理学重点实验室,江苏南京210008 [2]中国科学院南京土壤研究所,江苏南京210000

出　　处：《生态环境学报》2015年第2期255-262,共8页Ecology and Environmental Sciences

基　　金：江苏省科技厅项目(BE2014739;BZ2014005);国家自然科学基金项目(41371121);中国科学院支持全国科学院联盟建设专项重大项目;江西省科技支撑项目(20122BBG70160)

摘　　要：太湖地区经济高度发达,劳动力紧缺,种植小麦(Triticum aestivum)经济效益不高,而且小麦-水稻(Oryza sativa)轮作中,麦季氮素淋洗损失高于稻季,为探讨和揭示太湖流域典型稻-麦轮作农田区氮素流失过程及平衡特征,选取典型太湖流域农田系统为研究对象,采用径流小区的研究方法,在太湖流域典型稻-麦轮作种植模式下,对太湖流域典型稻-麦轮作区进行连续3年(2007─2010年)原位监测,阐明了太湖流域典型稻麦轮作区氮素流失过程及其影响因素,分析了该区域氮素平衡特征,结果表明:大气氮干沉降量冬春季较多且分布较均匀;总氮(P<0.001***)及铵态氮(P=0.02*)的大气湿沉降量和降雨量呈现极显著的相关性。地表径流中氮素的主要流失形态为可溶性氮素,同时,径流水量是引起氮素径流流失的主要驱动因子(P<0.01)。雨水是驱动小麦季氮素下渗的唯一动力。铵态氮是氮素淋失的主要形态,在稻作期,铵态氮渗漏流失量约占总渗漏流失量的70%。太湖流域稻麦轮作区,各项氮素年平均流失去向分别为:作物收割290 kg·hm-2,占总输入量55.98%;反硝化流失130 kg·hm-2,占总输入量25.10%;径流流失59.5 kg·hm-2,占总输入量11.49%;氨气挥发22.28kg·hm-2,占总输入量4.30%;渗漏流失16.1 kg·hm-2,占总输入量3.11%。全年平均氮素流失总量为518 kg·hm-2,氮素的盈余量为91.9 kg·hm-2。该研究结果对于指导太湖农流域农田水肥管理,控制农业面源污染具有积极意义。Economic benefits of raising wheat is poor in Taihu Lake region where the economy highly developed. Meanwhile the nitrogen leaching loss is extremely high in rice-wheat rotation farmland. In order to reveal the process of nitrogen loss as well as to explain the nitrogen balance characteristics in rice-wheat rotation farmland in Taihu Basin, a field experiment was carried out using a runoff-plot method. Based on the monitoring data from 2007 to 2010, nitrogen balance characteristics and process of nitrogen loss were illustrated. The results indicate that the dry deposition of nitrogen was mainly found in winter and spring and performed a homogeneous distribution, whereas the wet deposition of total nitrogen and ammonium nitrogen were dominated by the precipitation amount .The amount of runoff is the driving factor of nitrogen runoff loss. The main form of nitrogen loss in surface runoff was soluble nitrogen including nitrate and ammonium nitrogen. Ammonium nitrogen is the main form in nitrogen leaching loss. In the rice growing period, ammonium nitrogen leakage loss account for 70%of total leakage loss. Nitrogen balance characteristics were also illustrated that 55.98%of nitrogen was take away by harvesting and denitrification loss, runoff loss and leakage loss of nitrogen were account for 25.10%, 11.49%and 3.11%, respectively. The results have positive significances to the farmland management and agricultural nonpoint source pollution control.

关 键 词：稻-麦轮作 氮素 径流流失 渗漏流失 

分 类 号：X144[环境科学与工程—环境科学]