Winter cereal rye is a popular cover crop choice to protect fields from erosion over the winter months, aid in suppressing winter annual weeds, improve soil health and, in some cases, provide an alternative forage source for livestock. Looking ahead to the corn or soybean crop that will follow, growers need to give some thought to how they will terminate the cereal rye cover crop. Termination options include tillage, forage harvesting, chemical application, rolling/crimping and planting green.
If tillage is your termination method of choice, the earlier the better. Successful termination by tillage depends upon cutting the cereal rye roots. The more growth you have to deal with, the harder it can be to get the growth evenly dispersed and tilled under. You can end up with clumps of plant material and have a mess to deal with. Another tillage option is to make an application of glyphosate when growth is small and then use some vertical tillage to work the growth into the soil. Something to consider is that tillage undoes some of the benefits of planting a cover crop from a soil health perspective.
As an alternative forage option, cereal rye can provide one or more grazing passes before termination and rotation into a corn or soybean crop. Termination options after grazing include tillage or use of a glyphosate herbicide product. Another forage option is mechanically harvesting the cereal rye for an ensiled forage crop. When cereal rye is harvested in the reproductive growth stage, seedhead emergence and later, this typically terminates growth allowing the subsequent crop to be planted into the remaining stubble.
Chemical termination of cereal rye with a glyphosate herbicide is common and effective. Some general guidelines for best control include apply the glyphosate material when day temperatures are above 55 F and night temperatures are above 40 F, terminate before boot stage growth, add a non-ionic surfactant if not included in the glyphosate product formulation, and apply an acid equivalent rate of 1lb./acre. A presentation at the 2018 Midwest Cover Crop Council Meeting by Alison Robertson, Iowa State University Extension plant pathologist, on disease management when using cover crops concluded that winter cereal rye could be a green bridge for pathogens that cause seedling disease in corn. Under favorable seedling disease development conditions, this results in some yield loss. Therefore, the conclusion was to wait 10 to 14 days after cereal rye termination before planting corn to reduce this risk of seedling disease. There was not a corresponding detrimental effect on soybean seedling disease.
Crimping or rolling cereal rye offers a non-chemical termination option. Effective termination depends upon crimping or rolling after seedhead emergence. I can provide more information about this practice to anyone who is interested. This practice has been demonstrated at the small grain field day the past few years and will be demonstrated again at this year’s field day, which is scheduled for June 12 at the OARDC Schaffter farm on Oil City Road. Watch for more details about the field day in the coming weeks.
Finally, there are growers that have had success “planting green” into standing (5-6 feet tall) mature cereal rye. I have attended a couple of field days where corn was successfully grown under this production system. Some common recommendations include planting cereal rye at a reduced seeding rate in the fall and making sure that extra supplemental nitrogen is provided to the crop at planting time.
For more information about cereal rye as a cover crop and/or cover crop termination, contact the Wayne County Extension office at 330-264-8722.