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ARS Home » Southeast Area » Auburn, Alabama » Soil Dynamics Research » Research » Publications at this Location » Publication #411670

Research Project: Agronomic and Engineering Solutions for Conventional and Organic Conservation Agricultural Systems in the Southeastern U.S.

Location: Soil Dynamics Research

Title: Integrating cover crops and herbicides for weed control in soybean

Author
item KUMARI, ANNU - Auburn University
item Price, Andrew
item GAMBLE, AUDREY - Auburn University
item LI, STEVE - Auburn University
item JACOBSON, ALANA - Auburn University

Submitted to: Weed Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/11/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: In mid-South, southeastern, and northeast United States soybean production regions, the evolution of herbicide-resistant weeds has become a significant management challenge for growers. The issue of rising herbicide costs for managing herbicide-resistant weeds is also a growing concern, leading to the utilization of cover crops as an integrated weed management strategy for addressing these challenges. Field experiments were conducted at two locations in Alabama in 2022 to evaluate winter cereal cover crops including a mixture, and herbicide system integration in soybean. Our results show that cereal rye and the cover crop mixture provided weed biomass reduction compared to all cover crop treatments across both locations. Furthermore, we observed higher soybean yield following the cereal rye cover crop than the winter fallow treatment at one location. Postemergence and preemergence + postemergence herbicide treatment resulted in higher weed biomass reduction and improved soybean yield than the preemergence herbicide treatment alone and non-treated check at both locations.

Technical Abstract: In mid-South, southeastern, and northeast United States soybean production regions, the evolution of herbicide-resistant weeds has become a significant management challenge for growers. The issue of rising herbicide costs for managing herbicide-resistant weeds is also a growing concern, leading to the utilization of cover crops as an integrated weed management strategy for addressing these challenges. Field experiments were conducted at two locations in Alabama in 2022 to evaluate winter cereal cover crops including a mixture, and herbicide system integration in soybean. Treatments included five cover crops: oats, cereal rye, crimson clover, radish, and a cover crop mixture. Cover crops were evaluated for their weed-suppressive characteristics compared to a winter fallow treatment. Additionally, four herbicide treatments were applied: a pre-emergence (PRE) herbicide, a post-emergence (POST) herbicide, PRE plus POST herbicides, and a non-treated check. The PRE herbicide was S-metolachlor, the POST treatment contained a mixture of dicamba and glyphosate. The PRE plus POST system contained the PRE application followed by POST application. Our results show that cereal rye and the cover crop mixture provided weed biomass reduction compared to all cover crop treatments across both locations. Furthermore, we observed higher soybean yield following the cereal rye cover crop than the winter fallow treatment at one location. POST and PRE+POST herbicide treatment resulted in higher weed biomass reduction and improved soybean yield than the PRE herbicide treatment alone and non-treated check at both locations.