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ARS Home » Southeast Area » Auburn, Alabama » Soil Dynamics Research » Research » Publications at this Location » Publication #421480
Research Project: Agronomic and Engineering Solutions for Conventional and Organic Conservation Agricultural Systems in the Southeastern U.S.

Location: Soil Dynamics Research

Title: Evaluating the impact of cover crop mixture and cereal rye on soybean critical period for weed control in a low yield environment

Author
item KUMARI, ANNU - Auburn University
item Price, Andrew
item SINGH, JAGDEEP - Auburn University
item Balkcom, Kipling
item RUSSELL, DAVID - Auburn University

Submitted to: Weed Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/20/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Cover crops have been increasingly adopted as a sustainable approach to control problematic weeds, more specifically herbicide-resistant weed species (i.e., Palmer amaranth), to maintain soybean yield. Understanding of critical period of crop-weed competition is essential for effective weed management tactics in crop production systems. A field experiment was conducted in 2019 and 2020 at the E.V. Smith Research Center, Shorter, AL, to evaluate the effect of cover crop mixture (cereal rye, crimson clover, and hairy vetch) and a single species cereal rye on the critical period for weed control (CPWC) in soybean. In both years, single species cereal rye had the shortest while winter fallow had the longest CPWC duration in soybean. The results showed that the presence of cover crop delayed the beginning of weed removal (CTWR) approx. 2 wk. compared with winter fallow. Less weed biomass production was observed following both cover crop treatments compared with winter fallow throughout most crop growing seasons.

Technical Abstract: Cover crops have been increasingly adopted as a sustainable approach to control problematic weeds, more specifically herbicide-resistant weed species (i.e., Palmer amaranth), to maintain soybean yield. Understanding of critical period of crop-weed competition is essential for effective weed management tactics in crop production systems. A field experiment was conducted in 2019 and 2020 at the E.V. Smith Research Center, Shorter, AL, to check the effect of cover crop mixture (cereal rye, crimson clover, and hairy vetch) and a single species cereal rye on the critical period for weed control (CPWC) in soybean. The experiment was implemented in a split-plot design in which main plots included cover crop mixture, cereal rye and winter fallow treatments, and subplots had multiple durations of weed-free and weed interference. In 2019, the predicted duration of CPWC following cover crop mixture, cereal rye, and winter fallow treatments was 4.8 wk., 0.1 wk., and 5.1 wk. respectively. Moreover, in 2020 the estimated CPWC duration following a cover crop mixture, cereal rye, and winter fallow treatments was 1.4 wk., 0.1 wk., 2.6 wk., respectively. In both years, single species cereal rye had the shortest while winter fallow had the longest CPWC duration in soybean. The results showed that the presence of cover crop delayed the beginning of weed removal (CTWR) approx. 2 wk. compared with winter fallow. Less weed biomass production was observed following both cover crop treatments compared with winter fallow throughout most crop growing seasons. In conclusion, findings of the critical period could help soybean growers enhance the cost-effectiveness and efficacy of their Integrated Weed Management (IWM) practices utilizing cover crops.