The Influence of Prairie Strips Sown in Midwestern Corn and Soybean on Sediment Discharge

Submitted by barogers on Fri, 12/09/2022 - 10:47

Publication Type:



Sustainable Agriculture, Volume Masters of Science, p.94 (2022)


<p>In the U.S. Midwest agriculture has changed the land cover from biodiverse prarire to a strict corn rotation sequence. The change in land use has consequently degraded the soil's inhert ability to cycle nutrients and increased erosion rates. Efforts have been made to increase the amount of prairie vegetation on the landscape to provide ecological uplift while note competing with farm production. The use of native prairie vegetation planted as either a contour buffer strips or edge of field filter strip was added to the 2018 Farm Bill under the Conservation Reserve Program (CRP), called CP-43. In this thesis the incorporation of prairie vegetation planted in cropped fields was studied to evaluate its effects on sediment transport and rate of soil movement at different landscape positions. A paired comparison approach was used that included two treatments at multiple research sites: with prairie strips and without prairie strips (control). From 2016 to 2021, a runoff plot method was used to monitor sediment discharge with H-flumes installed at six sites. The mesh pad method was used between 2016 and 2020 to monitor rates of in-field soil movement at three landscape positions (top, mid- and foot slope) at a total of 12 sites. Five of the sites monitored had both methods applied so the relationship between in-field soil displacement patterns and edge of field sediment discharge could be examined. The prairie strip treatment at sites planted in corn has 96.8% (95% CI:60.2% to 99.7%, p-0.007) less sediment discharged than the control. The rates of in-field soil movement were not significantly different between the two treatments; however, the soil movement was affected by a significant interaction between landscape position within a field and the crop planted. The midslope and foot slope positions has 27.0% (95% CI: 3.2 to 56.0%, p=0.02) and 60% (95% CI, 60.4% to 97.0%, p,0.001) higher rates of soil movement in fields planted with corn than fields planted with soybean. The relationship between of crop planted and landscape position suggest that in certain years of a corn-soybean rotation and at different hillslope positions in a field that installation of prairie strips can significantly improve soil stability and reduce sediment discharge. Additional sites would need to be monitored for several years across more landscapes to fully capture the influence of prairie strips installed in cropped fields, however, this study advances the understanding of prairie woven back into the landscape and shows promise as a way to support more biodiversity in primarily agricultural landscapes.</p>