甘肃省农田氮磷流失特征及影响因素研究

Characteristics and Impact Factors of Nitrogen and Phosphorus Loss in Farmland in Gansu Province

为进一步摸清甘肃省当前生产条件下农田氮、磷流失污染现状及其影响因素,基于第一次污染源普查在甘肃设立的17个一般监测点和第二次污染源普查前在甘肃设立的17个面源污染国控监测点,对甘肃省农田土壤氮、磷流失特征及影响因素进行了调查研究。结果表明:影响氮磷面源污染的因素有施肥量、降水量、灌溉量、坡度、土壤性质、种植物类型、施肥方式、地面耕作方式等,其中施肥量、降水量和灌溉量为主控因素。甘肃省肥料总氮流失量20493.44 t/a,总磷流失量1387.93 t/a,总氮和总磷流失最多的地区为陇南市,最少的为嘉峪关市。

To further make clear the status of nitrogen(N)and phosphorus(P)loss pollution in the farmland and related impact factors under the current production conditions in Gansu Province.Based on the 17 general monitoring points established in Gansu Province in the First National Pollution Source Survey and the other 17 on-point source pollution national control monitoring points established in Gansu Province before the Second National Pollution Source Survey,characteristics and the impact factors of N and P loss were investigated in above 34 points.The results showed that the factors affecting the non-point pollution of N and P included fertilization amount,rainfall,irrigation amount,slope,soil properties,planting pattern,fertilization method,tillage method and so on.The amounts of fertilization,rainfall and irrigation were the key factors.In Gansu Province,the total N and total P loss reached 20493.44 t/a and 1387.93 t/a,respectively.The most serious loss located in Longnan City,while the least loss located in Jiayuguan City.