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ARS Home » Plains Area » Mandan, North Dakota » Northern Great Plains Research Laboratory » Research » Publications at this Location » Publication #427133
Research Project: Transdisciplinary Research that Improves the Productivity and Sustainability of Northern Great Plains Agroecosystems and the Well-Being of the Communities They Serve

Location: Northern Great Plains Research Laboratory

Title: Grazing and cover crop effects on soil health during transition to organic production

Author
item CARDOSO, ABMAEL - University Of Wisconsin
item Liebig, Mark
item Hendrickson, John
item Kronberg, Scott
item Clemensen, Andrea
item Archer, David
item Nieman, Christine
item KOHMANN, MARTA - University Of Wisconsin
item FRANCO, JOSE - Savanna Institute

Submitted to: Agrosystems, Geosciences & Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/1/2025
Publication Date: 9/27/2025
Citation: Cardoso, A.S., Liebig, M.A., Hendrickson, J.R., Kronberg, S.L., Clemensen, A.K., Archer, D.W., Nieman, C.C., Kohmann, M.M., Franco, J.G. 2025. Grazing and cover crop effects on soil health during transition to organic production. Agrosystems, Geosciences & Environment. 8:4. Article e70213. https://doi.org/10.1002/agg2.70213.
DOI: https://doi.org/10.1002/agg2.70213

Interpretive Summary: Switching to organic farming can be tough. During this time, farmers often struggle with keeping their soil healthy, managing weeds, and making a good profit. Certain farming practices — like rotating crops, planting cover crops, and using less tillage — can help build soil fertility. Adding perennial forages and grazing animals can also improve soil by boosting organic matter. Even though we know cover crops, forages, and grazing can be good for the soil, there have not been many studies looking at how they work specifically during the organic transition period. To help answer that, a study was done in Mandan, North Dakota, at the USDA research farm. The researchers tested six different reduced-tillage cover cropping systems, some with livestock and some without, to see how they affected soil health during the 3-year transition to organic. Soil samples were taken at the start and end of the 3 years and tested for physical, chemical, and biological traits. Some treatments showed changes in soil pH and soil organic carbon. However, soil aggregation got worse in all treatments. Overall, soil quality did not differ much between the different systems by the end of the study.

Technical Abstract: The use of perennial forages and cover crop mixtures during the transition to organic production can be useful, but information on appropriate mixtures and grazing practices for reducing tillage and preserving soil health is scarce. This study investigated the efficacy of six objective-based, reduced tillage cover cropping systems with or without livestock grazing to induce changes in soil condition (e.g., soil organic carbon, wet aggregate stability, extractable nutrients) and soil health on a fine sandy loam during the organic transition phase in the northern Great Plains. A randomized complete block design with a split-plot arrangement and four replicates was used in an experiment conducted at the USDA-ARS Northern Great Plains Research Laboratory, Mandan, ND USA. Main-plot factors were grazing vs. no grazing, while six cover crop mixtures (soil-building cover crop mix, pollinator cover crop mix, weed suppression cover crop mix, multipurpose cover crop mix, annual crop rotation, or perennial forage biculture) were the split-plot factors. Soil samples were collected from 0-10 and 10-30cm depths at the beginning and end of the 3-year organic transition period. Soil samples were analyzed for bulk density, pH, organic C, total N, and extractable nutrient concentrations. Wet aggregate stability was analyzed at 0-10 cm soil depth. No cover crop mixtures or grazing effect was observed on wet aggregate stability. However, wet aggregate stability decreased in all treatments after 3 yr of organic transition (from 58% to 43%). In general, soil pH decreased with the transition to organic systems. Soil organic C increased in both the grazed and un-grazed perennial forage biculture treatments, the un-grazed soil-building, annual crop rotation, and multipurpose cover crop mixes. Soil total N increased under the grazed annual crop rotation. Aggregated Soil Quality Index values did not vary between cover cropping systems after organic transition. Overall, results from this study suggest modest changes in soil properties during organic transition.