Graduation Term

3-6-2024

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

School of Biological Sciences

Committee Chair

William L Perry

Abstract

Nutrient loss from agricultural practices in the Midwest contributes to degradation in ecosystem structure and function. Subsurface drainage systems in tilled corn-soybean rotations that rely on fertilization results in up to 50% of fall fertilizer being lost to the environment. Solutions are needed to reduce nutrient pollution from Midwestern agriculture. Cover crops are a best management practice that shows potential to reduce nutrient loss from Illinois farms. However, due to economic concerns, cover crop usage in Illinois is low (6%). A novel winter oilseed, pennycress, has the potential to act both as a cover crop and a cash crop, benefitting both the environment and producers. The goal of this thesis is to explore the ability of pennycress to provide beneficial ecosystem services to agroecosystems of the Midwest. We conducted 4 studies on soil nutrients, porewater nutrients, and organic matter decomposition at the Illinois State University and Western Illinois University farms to determine the effectiveness of pennycress as a cool season nutrient sink. At the study sites plots of pennycress and fertilized pennycress were compared to a fallow reference treatment. We observed 61% reductions in soil nitrate-nitrogen, the primary pollutant of concern, and up to 69% reductions in soil porewater nitrate-nitrogen, relative to the fallow reference. Furthermore, we did not find differences in nutrient concentrations between fertilized and unfertilized pennycress. Pennycress effectively sequestered nitrate-nitrogen and retained this nitrate-nitrogen for long periods of time. Thus, we conclude pennycress is an effective tool to reduce nitrate-nitrogen pollution from tile-drained agricultural fields.

DOI

https://doi.org/10.30707/ETD2024.20240618063950179768.999944

Page Count

74

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