Submitted to: Computers and Electronics in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/27/2019
Publication Date: 1/15/2020
Citation: Delgado, J.A., Ascough II, J.C., Lighthart, N.P., Neer, D.L. 2020. Potential use of a new nitrogen trading tool to assess nitrogen management practices to protect groundwater quality. Computers and Electronics in Agriculture. 169:105195. https://doi.org/10.1016/j.compag.2019.105195.
Interpretive Summary: The NLEAP GIS 5.0 NTT is a quick and powerful tool that can provide a series of robust calculations about the impact of current nitrogen management practices across a large number of fields. The tool can quickly integrate information on nitrogen management, management practices for a crop rotation, weather, soil properties, and hydrology to assess their spatial and temporal effects on nitrogen dynamics and the potential for nitrogen losses to groundwater via nitrate leaching or to the atmosphere via ammonia volatilization and nitrous oxide gas emissions. It can quickly assess the spatial nitrogen losses across the simulated area by field and soil type, and temporal losses across the simulated time (e.g., 24 years). The NLEAP GIS 5.0 NTT can quickly sum all these losses across the simulated area, including nitrate leaching losses and direct and indirect emissions of N2O. The NLEAP GIS 5.0 can rapidly calculate the total nitrate leaching losses spatially for any combination of landscape and management across the evaluated area.
Technical Abstract: The Nitrogen Loss and Environmental Assessment Package (NLEAP) with Geographic Information Systems (GIS), version 5.0, with a Nitrogen Trading Tool (NTT) is a model that can be used to integrate site-specific information about soils, weather, and management to conduct quick assessments of nitrogen (N) management practices to increase N use efficiencies while minimizing N losses. This tool is a valuable resource that can be used to conduct quick assessments of risky combinations of management practices and landscapes across several fields to identify hot spot areas that are susceptible to nitrogen losses. The NLEAP GIS 5.0 NTT can quickly assess the temporal and spatial N losses of a given scenario simulated across all the fields and subtract them from the baseline scenario. This allows the user to compare scenarios and use the tool as a nitrogen trading tool to assess the potential reductions in nitrate leaching or emissions of nitrous oxide that may be achieved with a given management practice. The tool can be used to quickly assess the potential to use management practices to reduce the potential losses of reactive nitrogen to groundwater and the atmosphere, as well as the potential to trade these reductions in reactive nitrogen in water or air quality markets. It can quickly calculate the potential savings (reductions in) direct and indirect N2O emissions (and the carbon sequestration equivalent) achieved due to improvements in N management practices. The carbon sequestration equivalent could also be traded in air quality markets. There is potential to use the tool to assess which areas are more sensitive to nitrate leaching, which can impact groundwater quality, and to assess what would be the best management practices to implement in these areas for protection of groundwater quality.