Human activities such as agricultural fertilization and fossil fuel combustion have introduced a massive amount of anthropogenic nitrogen (N) in reactive forms to the environment. As agricultural fertilization is the single largest anthropogenic N source, an integrated approach to understand the interactions among agriculture, atmosphere, and hydrology is essential in examining human-altered N cycling. We have developed an integrated modeling system with agriculture EPIC, atmosphere WRF/CMAQ, and hydrology SWAT. This integrated system is useful tool for scientists and policy-makers to answer many questions on cycling of water, carbon, and nutrients for sustaining the food production while protecting the environment. This dataset is associated with the following publication: Ran, L., Y. Yuan, E. Cooter, V. Benson, J. Pleim, R. Wang, and J. Williams. An Integrated Agriculture, Atmosphere, and Hydrology Modeling System for Ecosystem Assessments. Journal of Advances in Modeling Earth Systems. John Wiley & Sons, Inc., Hoboken, NJ, USA, 11(12): 4645-4668, (2019).

The effectiveness of management actions in reducing the release of excess nitrogen (N) to the environment is best assessed if N fluxes across air, land and water are regularly quantified at relevant scales. This dataset contains comprehensive 2002, 2007, and 2012 inventories of inputs and non-hydrologic N losses along with fossil fuel emissions, food demand, and terrestrial N surpluses for all HUC-8 subbasins of the contiguous United States using peer-reviewed, publicly available datasets.

The effectiveness of management actions in reducing the release of excess nitrogen (N) to the environment is best assessed if N fluxes across air, land and water are regularly quantified at relevant scales. This dataset contains comprehensive 2002, 2007, and 2012 inventories of inputs and non-hydrologic N losses along with fossil fuel emissions, food demand, and terrestrial N surpluses for all HUC-8 subbasins of the contiguous United States using peer-reviewed, publicly available datasets.

,The effectiveness of nitrogen fertilizer in maximizing agricultural production and increasing economic returns for farmers has led to its widespread use. However, when this element is applied to a farming system, it can enter the surrounding environment via atmospheric, surface and leaching pathways. Consultants, extension agents, farmers, and other stakeholders need tools than can be used to quickly calculate the risk of nitrogen movement into the environment. The Nitrogen Index can assist users in making these assessments by integrating data on a series of management practices, weather conditions, soil characteristics and off-site factors. This tool has been tested using data from different agroecosystems across the United States, China, Mexico, Argentina, a Mediterranean region in Spain, and the Caribbean. It has performed well in comparing the effects of different management practices on nitrogen losses by distinguishing practices with high and very high risk levels from practices with medium, low and very low risk levels.,,

The average atmospheric deposition of nitrogen from 2015-2017 to 2016-2018 within a landscape analysis unit.