Abstract：
The increasing environmental abundance of reactive N (\'Nr\') entails many adverse effects for society such as soil degradation and eutrophication. In addressing the global surplus of N, there is a pressing need to quantify local sources and dynamics of Nr. Although quantified as an important anthropogenic source of Nr, the spatiotemporal patterns of ammonia (\'NH3\') emitted by dairy farming and its resulting pressure on local surface waters lacks quantification. Quantification could optimize farm management with minimized losses of valuable nitrogen and protection of freshwater ecology. This study aimed to unravel spatiotemporal dynamics of ammonia nitrogen emitted by a dairy farm in the atmospheric and aquatic geo-ecosphere. Atmospheric NH3 and aqueous ammonium (\'NH4+\') were determined over time, together with meteorological variables. Aquatic biomonitors (periphyton and phytoplankton) were employed to monitor the spatial impacts of cattle-stable emitted NH3. Atmospheric NH3 on the farm was significantly regulated by wind, sharply declining over increasing distances from the stable (average decrease in the dominant wind direction from 55.5 μg/m3 at 20 m to 5.8 μg/m3 at 500 m, in the other wind directions values decreased from 38.3 μg/m3 to 6.0 μg/m3). This was also reflected in local surface water concentrations of NH4+, with average concentrations decreasing from 37.0 mg [NH4+-N]/L at 65 m to 4.8 mg [NH4+-N]/L in the dominant wind direction, and from 1.2 to 0.7 in other directions. Periphyton biomass, total N (\"TN\") and δ15N all significantly reflected spatiotemporal dynamics of atmospheric NH3 and aqueous NH4+, as did phytoplankton TN. The cattle stable significantly influenced local water quality through atmospheric spreading of NH3, and both aquatic biomonitors were influenced by and reflected dairy farm emitted NH3 with a sharp dilution over distance. This study strongly underlines the importance of atmospheric transport of dairy farm emitted NH3 and its effects on local water quality.
摘要：
活性N（\'Nr\'）的环境丰度不断增加，对社会产生了许多不利影响，例如土壤退化和富营养化。在解决N的全球盈余时，迫切需要量化Nr的本地来源和动态。尽管量化为Nr的重要人为来源，奶牛养殖排放的氨（\'NH3\'）的时空模式及其对当地地表水的压力缺乏量化。量化可以优化农场管理，最大程度地减少宝贵的氮的损失并保护淡水生态。这项研究旨在揭示大气和水生地球生态圈中奶牛场排放的氨氮的时空动态。随着时间的推移，测定了大气中的NH3和氨水(NH4+)，连同气象变量。采用水生生物监测器（附生和浮游植物）来监测牛稳定排放的NH3的空间影响。农场的大气NH3受到风的显著调节，随着距离马厩的距离的增加而急剧下降(主导风向的平均下降从20米的55.5微克/立方米下降到500米的5.8微克/立方米，在其他风向上，数值从38.3μg/m3下降到6.0μg/m3）。这也反映在局部地表水中的NH4+浓度，在主要风向上，平均浓度从65m时的37.0mg[NH4-N]/L下降到4.8mg[NH4-N]/L，从1.2到0.7在其他方向。周生植物生物量，总N（“TN”）和δ15N均显着反映了大气NH3和NH4水溶液的时空动力学，浮游植物TN也是如此。稳定的牛通过NH3在大气中的传播显着影响了当地的水质，并且两个水生生物监测器都受到影响，并反映了奶牛场排放的NH3在远处急剧稀释。这项研究强烈强调了奶牛场排放的NH3在大气中运输的重要性及其对当地水质的影响。
