Ongoing water quality degradation tied to nitrogen and phosphorus pollution results in significant economic damages by diminishing the recreational value of surface water and compromising fisheries. Progress in decreasing nitrogen and phosphorus pollution to surface water over the past two decades has been slow. Limited resources need to be leveraged efficiently and effectively to prioritize watersheds for restoration. Leveraging recent nitrogen and phosphorus inventories for the years 2002, 2007, and 2012, we extracted relevant flux and demand terms to help identify US subbasins that are likely contributing a disproportionate amount of point and non-point source nutrient pollution to surface water by exploring the mean spatial distribution of terrestrial anthropogenic surplus, agricultural surplus, agricultural nutrient use efficiency, and point source loads. A small proportion of the landscape, <25% of subbasin area of the United States, contains 50% of anthropogenic and agriculture nitrogen and phosphorus surplus while only 2% of landscape contributes >50% of point source loads into surface water. Point source loads are mainly concentrated in urban areas across the country with point source loading rates often exceeding >10.0 kg N ha⁻¹ yr⁻¹ and >1.0 kg P ha⁻¹ yr⁻¹. However, the ability for future upgrades to wastewater treatment plant infrastructure alone is unlikely to drive further improvement in water quality, outside of local water ways, since point source loads only account for ~4% of anthropogenic N and P surplus. As such, further progress in boosting nutrient use efficiency in agricultural production, usually lowest in areas of intensive livestock production, would likely contribute to the biggest gains to water quality restoration goals. This analysis and the corresponding database integrate multiple streams of information to highlight areas where N and P are being managed inefficiently to give decision makers a succinct platform to identify likely areas and sources of water quality degradation.

与氮和磷污染相关的持续水质恶化会降低地表水的娱乐价值并损害渔业，从而造成重大的经济损失。过去二十年来，减少地表水氮磷污染的进展缓慢。需要高效、有效地利用有限的资源，优先考虑流域的恢复。利用 2002 年、2007 年和 2012 年的最新氮和磷库存，我们提取了相关的通量和需求术语，通过探索可能对地表水造成不成比例的点源和非点源营养物污染的美国子流域。陆地人为盈余、农业盈余、农业养分利用效率和点源负荷的平均空间分布。一小部分景观（占美国次流域面积的 <25%）包含 50% 的人为和农业氮磷盈余，而只有 2% 的景观向地表水贡献了 >50% 的点源负荷。全国点源负荷主要集中在城市地区，点源负荷率往往超过>10.0 kg N ha ^-1 yr ^-1和>1.0 kg P ha ^-1 yr ^-1 。然而，仅靠未来对污水处理厂基础设施进行升级的能力不太可能推动当地水道之外的水质进一步改善，因为点源负荷仅占人为氮磷盈余的 4% 左右。 因此，在提高农业生产养分利用效率方面取得进一步进展（通常在集约化畜牧生产地区效率最低）可能有助于实现水质恢复目标的最大成果。该分析和相应的数据库整合了多个信息流，以突出显示氮和磷管理效率低下的区域，为决策者提供一个简洁的平台来识别可能出现水质退化的区域和来源。