“Cover crops that have overwintered need to be terminated in a timely manner in the spring to avoid interfering with planting the row crop, taking up needed soil water in a dry spring, or acting as a weed for the subsequent crop,” says Dr. Dean Baas, Michigan State University Extension Educator and a specialist in sustainable agriculture and cover crops (CC). Dr. Baas spoke at the St. Joseph County IPM Breakfast Meeting series on April 26th on the topic of considerations with CC termination.
Baas discussed the four main ways that CCs are terminated in Michigan. Using CCs that winterkill is the simplest system and the easiest to manage which is why choosing species that are not winter hardy in this region is often recommended for farmers just starting out with CCs. Farmers should still have a back-up plan in case the plants do not winterkill. Rolling and crimping to crush the plant stems is a method that has the added benefits of smothering weeds and preserving soil moisture. However, if not done properly or at the right plant stage, the biomass can hinder planting the subsequent crop or not provide successful termination. Tillage is another common control method, but several passes may be required for species more difficult to kill like annual ryegrass.
“Although there are some benefits to the first three methods, chemical control is most often used in Michigan,” said Baas. There are several things to keep in mind when using herbicides to terminate a CC: choosing chemicals that will effectively kill the CC but not injure the cash crop; applying the herbicide at the proper CC growth stage; ensuring the CC is actively growing and that air temperatures are above 50 during the day and 40 at night; avoiding tank-mixing herbicides that will hinder each other; and being careful to comply with all restrictions on the herbicide labels.
According to the USDA’s Risk Management Agency, CCs must be terminated no later than five days after planting the cash crop but before crop emergence in Zone 4, which includes Michigan, if crop insurance will cover the cash crop. Dr. Baas recommends that all farmers planning to use CCs consult with their crop insurance agent about termination plans.
The IPM (integrated pest management) Breakfast Series is organized by the MSU Extension field crops team in southwest Michigan. The meetings will run through the end of June and will be held at the Royal Café in Centreville beginning at 7:00 AM. Each meeting will include an update of the major field crops grown in the region, including a crop and pest report, followed by a presentation from a guest speaker on a topic important to crop production. Participants can order breakfast and eat during the meeting. The speakers for May 3 will be Dr. David Hillger from Dow AgroSciences and Rod Stevenson from Monsanto Company who will be addressing the topic, “Upcoming Herbicide Tolerant Crops.” The meeting will be sponsored by Ayres Insurance in Schoolcraft and Colville Crop Insurance in Centreville, and CEU and RUP credits will be available. For more information on this breakfast meeting series, contact Eric Anderson at the MSU Extension Centreville office (269-467-5511).
Submitted by Eric Anderson, MSU Extension