No-till (NT) and cover crops (CC) used in concert improve agricultural sustainability in our region of Southern Wisconsin by increasing crop yield, protecting soil while enhancing soil health, protecting water quality by reducing nutrient loss and their use is socially acceptable, giving farmers “license to farm”- overall public approval from keeping the landscape green. However, difficult to control weeds which are glyphosate tolerant or resistant (GTRW) are now prevalent, threatening the combination. Current management recommendations include row cultivation or eliminating CC residue to increase herbicide efficacy, either of which will negate sustainability gains. We hypothesize that using winter rye as cover and managing its biomass differently than currently practiced will suppress problematic weeds, adding to CC functionality and overall sustainability.
Replicated strip-trials on 4 farms will evaluate winter rye cover crop use/ management (planting rate and termination timing) for weed suppression compared to current Extension recommendations for management of GTRW. We will monitor weed dynamics throughout the growing season and measure crop yield.
Outreach activities (with evaluation) will include a hands-on field day, interactions with highly engaged, regional farmer-led watershed groups and direct farmer-consultant communication through one of our projects partner farmers who is also a practicing crop consultant.
Project objectives from proposal:
- Determine if rye planting rate and delayed termination i.e. “planting green” are effective for controlling/suppressing problematic GTRW in no-till soybean. Soybean is the crop of interest because this rotational phase is where the problem is greatest
- Compare use of cover crops against current University of Wisconsin-Extension (UWEX) herbicide recommendations for GTRW suppression
- Determine if rye residue from traditional, preplant termination affects efficacy of preemergence residual herbicide
- Determine effect of termination timing on rye aboveground biomass and soybean yields
- Share results and experiences with farmers and technical advisors including UWEX Weed Science.