Advancing the Adoption of Artificial Nitrogen Sinks.

In watersheds that generate elevated delivery of agricultural nitrogen (N), constructed wetlands and denitrifying bioreactors hold great promise in sustaining agricultural productivity while also protecting the water quality. These “artificial N sink”systems are positioned to intercept drainage waters or N-rich groundwater and promote denitrification, the conversion of nitrate to N gases. Some of these practices are eligible for USDA EQIP support in select states (e.g., Iowa, Arkansas and Illinois), but widespread adoption is stymied by critical knowledge gaps, including the seasonal performance of different designs in different settings, longevity of treatment and lack of design criteria. Our integrated research, extension and education project seeks to advance the adoption and strategic placement of appropriate artificial N sink designs. Our website – www.artificialnsinks.org – is a conduit of information to farmers, farm advisors, agencies, researchers, and educators. Sections of the website include a Frequently Asked Questions page to provide background information to the viewers. We also developed a georeferenced international Atlas of these systems; by clicking on individual sites on the map, users can view contact information, read case studies, and link to additional resources. We are also building out sections of the website for webcasts, fact sheets, course curriculum, technical summaries, geospatial and soil survey interpretation for particular locations for siting, and guidance documents. Our research approach includes a synthesis of all peer-reviewed literature to date to determine the factors controlling denitrification in these artificial N sinks, identify limitations for use of artificial N sinks, and identify knowledge gaps in the research. Immediate outcomes of our project will include increased stakeholder knowledge of the utility and placement of artificial N sinks, undergraduate and graduate student training on artificial N sinks and increased ability to map specific locations suitable for these best management practices.