Michelle Bohnen

MS student

[email protected]

Current Research Interests

I research greenhouse gas exchange between the soil surface and the atmosphere. My research takes place in the Mesocosm Facility where emissions are measured such as nitrous oxide, carbon dioxide, water vapor, and methane. Specifically, my research focuses on nitrous oxide emissions from agriculture and management of these systems as well as the climate change impacts on agricultural nitrous oxide emissions. Nitrous oxide can be harmful for the environment due to it being an ozone depleting substance as well as its high global warming potential. Inorganic nitrogen fertilizer utilization causes water contamination by leaching and runoff as well as air pollution through soil microbial processes of denitrification and nitrification which can release nitrous oxide as an intermediate step or a by-product. Soil amendments have the potential to reduce synthetic nitrogen fertilizer use by supporting crop growth through alternative methods. One of my goals is to test a nitrogen-fixing soil amendment at various reduced fertilizer rates for its effectiveness in producing and optimizing substantial crop yields at different fertilizer rates. Another goal is to analyze the benefit of different reduced fertilizer rates on emissions. 

Additionally, climate change will generally increase freeze-thaw cycles on soils by increasing temperature. Freeze-thaw cycles on soil contribute a disproportionate amount of nitrous oxide to the atmosphere. This creates a positive feedback cycle that is detrimental to the environment. Another one of my goals is to quantify these emissions while examining the mechanisms and controls of this phenomenon. Cover crops can affect nitrogen in soil and emissions, and thus I am interested in testing how winter cover crops affect nitrous oxide emissions during freeze-thaw cycles. Additionally, enhanced efficiency fertilizers have the potential to decrease emissions through various mechanisms such as nitrification or denitrification inhibition. Therefore, I am testing an enhanced efficiency fertilizer in warmer temperatures for its ability to reduce nitrous oxide emissions in an anticipated warming climate. Water, soil, plant, and air sampling in these projects allows for analysis of reactive nitrogen cycling. These projects will aid in improving mitigation strategies and best management practices for greenhouse gas emissions from agricultural ecosystems that are a consequence of anthropogenic activities and climate change.

Educational Background

Bachelor of Science: Environmental Sciences, Policy, and Management major; Climatology minor, University of Minnesota-Twin Cities, 2022