Project Overview
Managing weeds and focusing on soil health are two areas of importance for organic farmers, but achieving high levels of weed control often comes at the cost of soil health due to the reliance on soil disturbance. Living mulches offer an opportunity to reduce tillage while also suppressing weeds and minimizing soil disturbance. However, living mulches may compete with the cash crop if not managed properly.
This study, conducted by the University of Wisconsin, examined the impacts of several living mulch management practices – including undercutting, flaming, roller-crimping, and high-residue cultivation – on the performance of a red clover living mulch in an organic grain corn system.
Farmer Takeaways
- Inter-row red clover roller crimping lowered clover height early in the season but did not affect clover biomass at the end of the season.
- Using a high-residue cultivator reduced clover biomass but did not affect corn yield.
- Undercutting or flame weeding clover resulted in greater corn yield compared to no-till management.
- Undercutting clover at corn planting increased weed biomass in the crop row but not between the rows, while high-residue cultivation increased between row weed biomass compared to roller crimping during the growing season.
Project Objectives and Approach
To evaluate red clover management strategies (pre- and post-corn planting) and their effects on clover growth, weed suppression, and corn grain yield.
- A field experiment was conducted from 2021-2022 at the University of Wisconsin Arlington Agricultural Research Station, with red clover as the living mulch cover crop and organic silage corn as the cash crop.
- Treatments consisted of:
- 1) pre-corn planting tillage strategy: undercutting the red clover to create a planting strip vs. no-till direct seeding corn into the clover living mulch
- 2) post-corn planting clover management: flame weeding of the red clover vs. no flame weeding
- 3) in-season red clover management: inter-row roller crimping vs. high-residue cultivation, or a combination of the two.
- Data was collected on red clover height and biomass (prior to and after management strategies), weed biomass, corn population counts, and corn yield.
Key Findings
Inter-row roller crimping 2- and 4-weeks after planting corn reduced red clover height, but did not impact red clover biomass at the end of the growing season.
- Red clover height was reduced by an average of 3.15 inches (8 cm) by inter-row roller crimping during the growing season, but overall biomass was unaffected.
- Flame weeding did not affect clover height.
In-season high-residue cultivation reduced between-row red clover biomass compared to roller crimping, but corn yield was unaffected.
- Red clover biomass between the crop rows averaged 465 lb/ac for high-residue cultivation compared to 741 lb/ac in the roller crimping treatment, suggesting that high-residue cultivation can affect the living mulches ability to suppress weeds through its biomass, but this may not always translate to a crop yield effect.
- Corn yield averaged 70 bu/ac and 74 bu/ac in the high-residue cultivation and roller crimping treatments, respectively.
Compared to no-till corn planting, undercutting or flame weeding the red clover living mulch at planting resulted in greater corn yield.
- Undercutting resulted in corn yield of 86 bu/ac and flame weeding 79 bu/ac, compared to 60 bu/ac in the no-till treatment.
- Greater yield is likely attributed to an increase in soil temperature caused by tillage soil disturbance, which can lead to quicker crop emergence. Termination of the living mulch to create the crop planting furrow can also reduce competition for N between a crop and living mulch.
Effects on weed management varied and depended on treatment, and were likely attributed to where soil disturbance occurred in the treatments (in or between the crop row).
- Undercutting red clover increased weed biomass in the crop row, and high-residue cultivation increased weed biomass between the crop row.
- Soil disturbance can stimulate weed seed germination, and coupled with living mulch disturbance, can create an environment for weed emergence and growth.
Resources
Brockmueller, B., Drewry, J. L., Vereecke, L., Silva, E.M., & Luck, B. (2025). Mechanical management strategies improve corn production in organically managed living mulch systems. Agronomy Journal, 117, e70100.
Read MoreLocation
WisconsinCollaborators
Jessica L. Drewry, Department of Biological Systems Engineering, University of Wisconsin, Madison
Léa Vereecke, Department of Plant Pathology, University of Wisconsin, Madison
Erin M. Silva, Department of Plant Pathology, University of Wisconsin, Madison
Brian Luck, Department of Biological Systems Engineering, University of Wisconsin, Madison
Region
Midwest
Topic
Weed Management
Category
Grain and Field Crops
Year Published
2025
