Cereal rye has emerged as the frontrunner for planting cover crops that suppress early-season weed emergence, especially among stubborn pigweeds like Palmer amaranth and waterhemp.
But when do you terminate your cover crop for the best effect? That’s a question researchers at multiple universities hope to answer in a 3-year study that’s now entering its third season.
In this video, Jason Norsworthy summarizes the USDA-funded study, which is being conducted by 15 researchers through a large swath of the U.S. Norsworth, a University of Arkansas weed scientist, also discusses his state’s findings so far.
With more resistant weeds turning up on a broader scale every year, cover cropping has gained traction as a tool for dealing with weeds as standard herbicide approaches lose horsepower.
Cover crops can reduce soil temperature, which suppress weed seed germination and seedling vigor. Dead stems and leaves from the terminated cover limit the quality and quantity of sunlight that reaches the soil.
Cereal rye plants rapidly build biomass in the spring, which may provide better weed suppression. Deciding when to terminate cereal rye is a key factor in determining how well the cover crop retards growth.
The study’s multiple locations should improve scientists’ understanding of cereal rye termination timing on weed suppression and clarify geographic differences in how the system works.