Understanding Plant Selection as a Tool for Managing Trade-offs in Water Quality and Greenhouse Gas Emissions in On-Farm Wetlands

Poster 208 – Click on poster below to view presentation from author.

Click on poster to view presentation from author.

Danielle Winter

Purdue University

Co-Authors: Sara McMillan, Jacob Hosen

Creating and restoring wetlands on farms can reduce nutrient export from row-crop agriculture. While agricultural wetlands can improve water quality, wetlands may also be a source of potent greenhouse gases (GHGs), such as nitrous oxide and methane, that contribute to climate change. We posit that certain types of wetland plants based on residue composition will maximize complete denitrification, while reducing the release of potent GHGs. Wetland plant residue influences the composition and long-term fate of soil organic matter (SOM), thereby regulating lability of SOM and microbial processes that influence water quality and GHG emissions. Our proposed model is a wetland in central Indiana with emergent plant communities and a shallow impoundment that drains surrounding farmland. To test our hypothesis, we are 1) measuring denitrification, sulfate reduction, and GHG production rates across wetland soils underlying different plant communities, 2) conducting experiments to test the effect of plant residue at multiple stages of decomposition in microcosm experiments, and 3) characterizing the composition of added plant residue, the nature of SOM, and other soil properties. Preliminary results demonstrate that the type of wetland plant residue significantly affects methanogenesis and denitrification rates. Additionally, total and incomplete denitrification rates vary significantly across soils underlying different plant communities. By focusing on identifying vegetation-related controls of water quality improvements and GHG production, we have the potential to guide wetland creation and restoration design to maximize the benefits of embedding wetlands in agricultural landscapes.

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All posts are publicly visible after review by site administrator. Students’ responses to posted questions is factored into scoring for the poster competition. Finalists announced May 25 and awards presented May 26, 2021.

2 thoughts on “Understanding Plant Selection as a Tool for Managing Trade-offs in Water Quality and Greenhouse Gas Emissions in On-Farm Wetlands

  1. A fascinating and I think important area of inquiry. As we try to more and more “manage” wetlands, both man-made and natural, we are almost never dealing with an undisturbed ecosystem. Many wetlands are also infested with exotic invasive plants. If we are going to try to manage the vegetation of our wetlands (I think we should), then we need the kind of information you are exploring to find the best fit of plants for our human goals of treating pollutants and and reducing methane production, which at the same time maintaining important ecological functions. Thanks for picking this area to explore. Look forward to your discoveries!

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  2. Danielle, this is excellent work! Thank you for sharing it with us! I was wondering if you could tell me a bit more about the plants in your study – is there a reason you would suspect they would produce residues with different labilities? Or were you just trying to test out different plants and had these ones at hand?

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