Integrated Weed Management in Organic No-Till Planted Soybean
No-till planting organic soybean [Glycine max (L.) Merr.] into rolled-crimped cereal rye (Secale cereale L.) can have several advantages over traditional tillage-based production. However, suboptimal cereal rye growth in fields with large populations of weeds may result in reduced weed suppression, weed-crop competition, and soybean yield loss. Ecological weed management theory suggests that integrating multiple management practices that may be weakly effective on their own can provide high levels of weed suppression. In 2021 and 2022, field experiments were conducted in central New York to evaluate the performance of three weed management tactics implemented alone and in combination in organic no-till planted soybean: 1) increasing crop seeding rate, 2) inter-row mowing, and 3) weed electrocution. An untreated control and weed free treatment that did not receive any weed management were also included. All treatments that included inter-row mowing had lower weed biomass and higher soybean yield than the untreated control. Using a high seeding rate or weed electrocution did not improve weed suppression or soybean yield. Soybean yield across all treatments was at least 22% lower than the weed free control plot. Inter-row mowing was effective at controlling annual broadleaf weed species that grew between soybean rows, however, few weeds grew above soybean plants before canopy closure, which limited the effect of weed electrocution. Future research should explore the direct effects of the multiple tactics on weed population and community dynamics over an extended period and the indirect effects from tactics such as improved harvestability and impacts of weed electrocution on weed seed viability and soil organisms.