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1992～1995年,在位于挪威东南的Auli河主流域(366km~2)以及六个子流域进行了关于氮输入和损失的深入而细致的研究。以农业水文年为计算单位,从1992/1993～1994/1995年在Auli河干流出口处氮的总迁移量分别为20.6、19.1和26.5kg N/hm~2·a。此流域氮总输入量的约85%与农业活动有关,其中65%～70%来自无机化肥,只有15%来自远距离的大气沉降。不同年份氮的输入量变化并不大,但氮的输出量随气候条件变化很大。因此,某一特定年份氮的剩余量主要取决于那一年农作物的产量。在这次研究期间,整个流域氮的剩余量为20～41kg N/hm~2。大量的氮剩余会增加硝酸盐的淋溶风险,但其它因素,如数量、强度、降雨时间以及冬季的净矿化作用在很大程度上会影响氮的损失。三年时间里农业流域中氮的平均迁移量为65kg N/hm~2·a,而在森林流域氮的迁移量则低得多,其变化幅度为2～10kg N/hm~2·a。农业氮损失是造成主河流中氮迁移的最重要的因素。
From 1992 to 1995, in-depth and meticulous research on nitrogen input and losses was carried out in the main Auli river basin (366 km 2) and the six sub-basins in southeastern Norway. Taking the agricultural hydrological year as the unit of calculation, the total nitrogen migrations at the outlet of the main Auli river from 1992/1993 to 1994/1995 were 20.6, 19.1 and 26.5 kg N / ha, respectively. About 85% of the total nitrogen input to the basin is related to agricultural activities, of which 65% to 70% come from inorganic fertilizers and only 15% from long-distance atmospheric deposition. Nitrogen input in different years does not change much, but the output of nitrogen varies greatly with climatic conditions. Therefore, the remaining amount of nitrogen in a given year mainly depends on the crop production in that year. During this study, the remaining nitrogen in the entire basin ranged from 20 to 41 kgN / hm2. Large amounts of nitrogen remaining increase the leaching risk of nitrate, but other factors such as quantity, intensity, rainfall time, and net mineralization in winter largely affect nitrogen losses. In the three years, the average nitrogen migration in agricultural watershed was 65kg N / hm ~ 2 · a, while the nitrogen migration in forest watershed was much lower with a variation range of 2 ~ 10kg N / hm ~ 2 · a. Agricultural nitrogen loss is the most important factor contributing to nitrogen migration in the main rivers.