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Our project will combine research, education, and extension on using tile-fed constructed wetlands and wood chip tile bioreactors to reduce nitrate losses in the upper Embarras River watershed in east-central Illinois, a dominantly tile-drained, agricultural watershed. Specific objectives included for our tile-drained agricultural watershed in east-central Illinois are to:<OL> <LI> determine the effectiveness of both new and previously established tile-fed constructed wetlands in reducing nitrate export from corn and soybean fields, as well as measure wetland greenhouse gas emissions (N2O, CH4, and CO2) (research objective); <LI> determine the effectiveness of wood chip tile bioreactors in reducing nitrate export from corn and soybean fields, including measurements of greenhouse gas emissions from the bioreactor bed (N2O, CH4, and CO2) (research objective); <LI>demonstrate how constructed wetlands and tile bioreactors can reduce nitrate loss from fields with a variety of outreach tools (extension objective); <LI>evaluate the acceptance by stakeholders of constructed wetlands and tile bioreactors that reduce nitrate loss from fields, including possible incentives needed to implement either practice to obtain watershed scale improvements (research and extension objective); <LI>develop both seminar/discussion and field-based courses for undergraduate and graduate students (including a Hispanic-Serving Institution), leading to students equipped with both biophysical and social science skills who can deal with watershed scale water quality issues (education objective); <LI>involve Illinois 4-H kids in local water quality issues through development of a wetland module and hands on activities in the watershed (education objective). </ol> Major specific accomplishments will include: installation of three wood chip tile bioreactors; instrumentation of three previously established wetlands; establishment and instrumentation of two additional wetlands in other areas of the watershed; understanding of current stakeholder attitudes towards water quality and adopting tile bioreactors and wetlands from interviews and surveys; develop Illinois 4-H module on wetlands; results on effectiveness of established and new wetlands in reducing nitrate loss; results on tile bioreactors in reducing nitrate loss; greenhouse gas measurement summary and methyl Hg export from bioreactors; field and seminar/discussion courses taught, focused on integration of biophysical and social science on water quality in the watershed; work with Illinois 4-H kids on the watershed; measurement of effectiveness of extension programming, and how stakeholder motivation, acceptance, and views of wetlands and bioreactors have changed; and an understanding of how our education program has affected student learning and views about water quality.
Non-Technical Summary: <BR>Tile-drained corn and soybean fields in the upper Midwest are the major source of nitrate delivered by the Mississippi River to the Gulf of Mexico each winter and spring. This is a major factor in causing the hypoxic zone that forms each summer in the Gulf. The flat, productive soils of the upper Midwest produce high yields of crops, but the tile-drainage needed to make agricultural production practices feasible and timely on these fields often leak large amounts of nitrate. Therefore, the long-term goal of our project is to develop techniques that could lead to large watershed scale reductions in nitrate export. Our project will focus on the effectiveness of constructed wetlands and woodchip bioreactors, both of which are placed at the end of tile lines before they enter a ditch or stream. This work will be conducted in the Embarras watershed in east-central Illinois, where we have been sampling water quality since 1993. We will work cooperatively with a range of interested stakeholders on this watershed. New constructed wetlands and bioreactors will be installed with monitoring equipment on cooperators fields, and we will use some wetlands built in 1994 to assess long-term performance. We will determine how well these end-of-pipe techniques work in reducing nitrate export, as well as determining whether they contribute greenhouse gases during nitrate removal. We will implement a full range of extension activities including fact sheets that highlight research results and document the water quality benefits of the project and field days to demonstrate results to producers, landowners, and the general public. Interviews and surveys will assess stakeholder interests and motivations before and after extension programming. At the end of our study we will have a thorough understanding of how well wetlands and bioreactors work to reduce nitrate loss from fields and their greenhouse gas impact, as well as knowledge of stakeholder acceptance and barriers, effective extension programs, and evaluations of our work. This will help to design programs to reduce nitrate loss across the tile-drained Midwest. We will educate undergraduate and graduate students in our departments about water quality and how wetlands and bioreactors work, as well as develop a course for students from Northeastern Illinois University (an Hispanic Serving Institution). Finally, we will work with Illinois 4-H, educating kids about wetlands. <P> Approach: <BR> The watershed we will work on is the upper Embarras River watershed above the USGS gage (03343400) near Camargo, Illinois (48,100 ha in size). We have been sampling this site weekly to daily since 1993 and now have a continuous 18 year record of nitrate export from the watershed. This dataset provides us with an excellent understanding of seasonal nitrate loading and allows us to evaluate long-term trends on a decadal scale. Many of our previous studies have been on this watershed, as it is typical of the flat, tile-drained upper Midwest, and is nearly all agricultural in land cover. We will continue and expand water quality monitoring on the watershed to provide to all stakeholders a clear record of nitrate concentrations and export, as well as overall water quality in the watershed. We will sample weekly at the outlet USGS gage site throughout the year, with additional samples during major flow events (daily sampling is adequate from our past experience). This water quality sampling includes nitrate, ammonium, total N, dissolved reactive P (DRP), and total P. We will install two new wetlands and reinstrument three established wetlands (built in 1994) in the watershed on local farms, illustrating different types of landscape positions where they might be suitable. We will install three woodchip tile bioreactors in the watershed, following the latest design protocols. All wetlands and bioreactors will be monitored for flow using pressure transducers and dataloggers and equipped with automatic samplers for water sample collection. Water samples will be analyzed for nitrate, ammonium, total phosphorus, and dissolved reactive phosphorus, as well as selected samples for dissolved organic carbon and sulfate. Greenhouse gas fluxes (CO2, CH4, and N2O) will be measured using static chambers in both wetlands and bioreactors, with floating chambers used when wetlands are flooded. These results will allow us to determine how well wetlands and bioreactors function in removing nitrate during different seasons and precipitation patterns. We will also have a full assessment of greenhouse gas contributions from the wetlands and bioreactors. We will develop extension materials to help recruit farmers to cooperate with us on this project. We will have field days to show the latest results from our measurements of wetlands and bioreactors. We will conduct interviews and surveys before and after our extension activities, that will allow us to evaluate our efforts. Courses will be developed for students within our departments, but also with Northeastern Illinois University, and a Hispanic-Serving Institution. Finally, we will develop a wetland module for use by Illinois 4-Hand that involves hands on activities.