Agricultural activities are responsible for three quarter of global nitrate (NO₃) pollution. Many surface and ground water resources have been detrimentally affected from high rate of nitrogen (N) deposition due to excessive fertilizer and manure application. Grey water footprint (GWF) is one of the internationally accepted indicators quantifying the environmental effects of contaminants on water bodies. The main scope of this study is to assess GWF of agricultural nitrogen utilization in Turkey using Tier-1 approach, which is proposed by Water Footprint Network considering detailed spatially continuous soil, climate and agricultural data in order to provide quantifications at both provincial and basin level. Leaching runoff fractions of diffuse N loads are very important for GWF accounts. However, the previous studies are mainly relied on assigning constant leaching runoff fractions and superficial N applications rates. Nevertheless, many studies reported remarkable variations in leaching fractions due to heterogeneities in soil and water resources. To the author's knowledge, this is the first GWF assessment of the study area employing high resolution leaching runoff fractions which is estimated using soil texture, natural drainage and climate data maps. Nitrogen emissions and GWF accounts of 81 administrative provinces and 25 hydrological basins were quantified using provincial N application and surplus amounts. Accordingly, GWF of anthropogenic N accumulation is estimated to be 24.7 Gm³/y corresponding to an average water height of 114 mm per agricultural land area and 340 m³ per capita for the time period of five years (2007–2011). The water pollution level (WPL) is found to be critical (>0.75) at several river basins while the national average WPL is around 0.13. This study is expected to contribute to the national and international water and agricultural management and planning studies in order to decrease the water pollution levels by providing suitable information to policy-makers.

农业活动占全球硝酸盐的四分之三（NO ₃）污染。由于过多的肥料和肥料施用，许多地表和地下水资源受到高氮（N）沉积速率的不利影响。灰色水足迹（GWF）是量化污染物对水体的环境影响的国际公认指标之一。本研究的主要范围是使用Tier-1方法评估土耳其农业氮利用的GWF，该方法是水足迹网络在考虑详细的空间连续土壤，气候和农业数据的基础上提出的，以便在省级和流域级提供定量。NWF负荷的淋溶径流分数对于GWF帐户非常重要。但是，以前的研究主要依靠分配恒定的淋溶径流分数和表面氮肥施用量。然而，许多研究报告说，由于土壤和水资源的异质性，浸出部分存在显着变化。据作者所知，这是使用高分辨率淋溶径流分数对研究区进行的首次GWF评估，可通过土壤质地，自然排水和气候数据图进行估算。使用省N施用量和剩余量对81个行政省和25个水文流域的氮排放和GWF账户进行了量化。因此，人为氮积累的GWF估计为24.7 Gm 这是全球研究基金会对研究区的首次评估，采用高分辨率淋滤径流分数，该分数通过土壤质地，自然排水和气候数据图进行估算。使用省N施用量和剩余量对81个行政省和25个水文流域的氮排放和GWF账户进行了量化。因此，人为氮积累的GWF估计为24.7 Gm 这是全球研究基金会对研究区的首次评估，采用高分辨率淋滤径流分数，该分数通过土壤质地，自然排水和气候数据图进行估算。使用省N施用量和剩余量对81个行政省和25个水文流域的氮排放和GWF账户进行了量化。因此，人为氮积累的GWF估计为24.7 Gm³ / y对应于五年（2007-2011）期间每个农田的平均水高114毫米，人均340 m ³。在几个流域，水污染水平（WPL）被认为是临界水平（> 0.75），而全国平均水污染水平在0.13左右。预期该研究将有助于国家和国际水和农业管理与规划研究，以便通过向决策者提供适当的信息来减少水污染水平。