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ARS Home » Midwest Area » St. Paul, Minnesota » Soil and Water Management Research » Research » Publications at this Location » Publication #413531

Research Project: Developing Aspirational Practices Through Improved Process Understanding to Protect Soil and Air Resources and Increase Agricultural Productivity in the Upper Midwest U.S.

Location: Soil and Water Management Research

Title: USDA LTAR network research: Upper Mississippi River Basin – St. Paul, MN

item Dalzell, Brent
item Baker, John
item Venterea, Rodney - Rod
item Spokas, Kurt
item Feyereisen, Gary
item Rice, Pamela
item Alexander, Jonathan

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/2/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: The USDA-ARS Soil and Water Management Research Unit in St. Paul, MN, is conducting long-term research integrating kura clover into the typical corn-soybean rotation of the Midwest. The aim is to understand the environmental and agronomic impacts of this conservation practice. Benefits of kura clover living mulch include improved soil quality and reduced nitrogen leaching, but there are challenges like potential nitrous oxide emissions and reduced yields in droughts. Ongoing research aims to find solutions to these challenges and engage stakeholders for practical implementation.

Technical Abstract: The Soil and Water Management Research Unit of the USDA-Agricultural Research Service is located in St. Paul, Minnesota and conducts long-term research at the University of Minnesota Research and Outreach Center located at Rosemount, MN. As part of USDA’s Long Term Agroecosystem Research (LTAR) network, the cropland common experiment (CCE) at this location is focused on integration of a kura clover (Trifolium ambiguum M. Bieb.) living mulch (KCLM) system into the prevailing two-year rotation of corn (Zea mays L.) and soybean (Glycine max L.) that is typical of the midwestern corn belt. The LTAR-CCE conducted at Rosemount, MN aims to compare the long term environmental and agronomic performance of KCLM while identifying challenges and developing management strategies for this alternative practice. The use of a living mulch for this region is advantageous because, once established, it does not require additional time for fall field operations typically associated with winter cover crops. Results from LTAR-CCE studies at this site show that KCLM results in a substantial increase in soil field-saturated hydraulic conductivity and decreases in leaching of nitrate-nitrogen (NO3--N). Disadvantages of the KCLM system include potential for increased emissions of nitrous oxide (N2O) and reduced crop yields, particularly during drought. Also, the optimal approach for crop row establishment in the spring remains uncertain. Ongoing LTAR-CCE research with KCLM aims to better understand and quantify both benefits and risks across conditions of interannual weather variability and changing climate to develop guidance for suitable adoption and management of this alternative practice.