东北三省农田化肥氮地下淋溶污染等级评估

本研究以我国东北三省（黑龙江、吉林、辽宁）为研究对象，统计了东北36个市级行政单元的化肥施用情况，分析了东北三省近10年的化肥施用趋势，并利用地理信息系统揭示了化肥施用空间特征。在此基础上，利用氮地下淋溶流失系数估算了农田化肥氮地下淋溶流失量，量化了东北三省各行政单元的氮地下淋溶流失强度。结果表明，近10年我国东北化肥施用量呈上升趋势，吉林省化肥施用强度最高，其次是辽宁省和黑龙江省；氮地下淋溶流失强度的平均值为0.314 4 kg·hm^-2·a^-1，氮地下淋溶高流失强度区主要集中在吉林省的长春市、四平市等地区，原因在于吉林省化肥施用量较高，同时玉米产量高，而玉米相对于其他作物，其氮肥施用量和氮素地下淋溶流失系数均处于较高水平。本研究相关方法可用于区域尺度上的农田氮地下淋溶估算，同时研究结果为我国农田面源污染防控和氮素管理提供了数据支持。

Pollution grade assessment of nitrogen leaching from farmland fertilizer in three northeastern provinces

In this study, three northeast provinces, including Heilongjiang Province, Jilin Province and Liaoning Province in China were targeted as the study area, the situation of fertilizer application was collected the trend of fertilizer application was analyzed in the recent ten years based on the collected data of fertilizer of 36 cities. The GIS tool was used in providing the spatial distribution map of nitrogen leaching in this region. On this basis, we utilized the leaching coefficient to estimate nitrogen leaching and quantified leaching intensity for identifying those high-risk regions. The results showed that fertilizer application had been increasing during the past 10 years in three northeast provinces, Jilin Province had the highest intensity of fertilizer application, followed by Liaoning Province and Heilongjiang Province; the average leaching intensity of nitrogen was 0.314 4 kg·hm^-2·a^-1, with highest leaching intensity was centered in Changchun City, Siping City and so on. Because of their higher maize yield with higher fertilizer application is at the highest level in Jilin Province, nitrogen fertilizer demand and nitrogen leaching loss coefficient of maize were higher compared with other crops. This study provided the computing method of nitrogen leaching on the regional scale, and provided data support for prevention of agricultural non-point source pollution and nitrogen management.