In the present work, we have synthesized agricultural, population, and atmospheric deposition data across the contiguous U.S. for the period 1930-2017 to develop the Trajectories Nutrient Dataset for Nitrogen (TREND-nitrogen). The data is provided at U.S. county scale at an annual time step, and the following components of the N mass balance are included: atmospheric N deposition, N fertilizer, biological N fixation, manure N, crop N uptake, human N waste, and the overall N surplus. The dataset was constructed using information from a variety of sources, including the U.S. Census of Agriculture, the National Atmospheric Deposition Program, the United States Geological Survey, and the U.S. Census Bureau. Gap-filling and data-fusion techniques were utilized to provide annual-scale coverage and to harmonize data obtained from disparate sources over different time periods and varying spatial scales. The dataset will facilitate investigations of spatial and temporal changes in anthropogenic N dynamics at multiple scales across the U.S. in the context of historical changes in population, land use, and management.

This dataset is associated with Byrnes et al. (2020). Global Biogeochemical Cycles. doi:10.1029/2020GB006626. This data should only be used to replicate the study. For updated data, please refer to the most recent version of the dataset Byrnes et al. (2022). doi:10.6084/m9.figshare.20915989.v1