Boumans Leo, Fraters Dico, van Drecht Gerard
National Institute for Public Health and the Environment, Bilthoven, The Netherlands.
Environ Monit Assess. 2004 Apr-May;93(1-3):1-15. doi: 10.1023/b:emas.0000016788.24386.be.
Anthropogenic increase in atmospheric nitrogen (N) deposition in nature areas results in nitrate leaching to groundwater, threatening its quality. Member states of the European Union are obliged to reduce groundwater nitrate concentrations and to monitor this reduction. The relationship between N deposition and groundwater nitrate concentrations is quantified using a field survey and geographical information. Nitrate concentrations of the uppermost metre of groundwater in nature areas in the sandy regions in 1990 were related to geographical data by means of regression analysis. In this way nitrate concentrations could be explained by potential ammonia deposition, soil type, vegetation and land use. We found that about 35% of 54 kg ha(-1) a(-1) atmospheric N deposition was leached to the upper groundwater as nitrate, resulting in a mean NO3 concentration of about 30 mg L(-1). The critical N load for exceeding the EC limit value (50 mg L(-1)) in the sandy regions of The Netherlands composed of natural vegetation will be about 80 kg ha(-1) a(-1). Leaching is less than expected for nature areas but comparable with leaching of N surpluses in pastures in The Netherlands. A reduction in nitrate leaching by 25% or more can currently be detected via a new field survey.
自然区域大气氮（N）沉降的人为增加导致硝酸盐渗入地下水，威胁其水质。欧盟成员国必须降低地下水中硝酸盐的浓度并监测这种降低情况。利用实地调查和地理信息对氮沉降与地下水中硝酸盐浓度之间的关系进行了量化。通过回归分析，将1990年沙质地区自然区域地下水中最上层一米的硝酸盐浓度与地理数据相关联。通过这种方式，硝酸盐浓度可以由潜在氨沉降、土壤类型、植被和土地利用来解释。我们发现，54千克/公顷·年的大气氮沉降中约35%以硝酸盐形式渗入上层地下水，导致平均硝酸盐浓度约为30毫克/升。在荷兰由自然植被构成的沙质地区，超过欧盟限值（50毫克/升）的临界氮负荷约为80千克/公顷·年。自然区域的淋溶量低于预期，但与荷兰牧场氮盈余的淋溶量相当。目前通过一项新的实地调查可以检测到硝酸盐淋溶减少25%或更多。
