While many cover crops are being planted following corn/soybean rotations to reduce soil erosion, increase soil health, and even for weed control, some producers also desire to use their cover crops for grazing and/or forage. A question that has been starting to pop up frequently this fall is “can cover crops be fed as forage?” More specifically, “can a cover crop be used as forage if the species was seeded following a soybean/corn herbicide program?” And the answer to that question is, it depends on the previous herbicides that were applied on that field and the specific rotation restriction listed on the herbicide label.
What many producers don’t think to consider when it comes to the issue of grazing or feeding their cover crops is that once a herbicide is used in the previous corn or soybean crop, the grazing and feeding restrictions on those herbicide labels must be followed for that crop AND the subsequent cover crop until the restrictions on those labels have been met. If the specific cover crop species you have planted is not listed on the herbicide label, this does not mean that the species you have planted can legally be fed or grazed. In fact, most of the species being utilized for cover crops are not specifically mentioned on current herbicide labels. In those cases, growers must fall back to the default listing on the label, which usually states something to the effect of “all other crops” or “all others” to find the grazing and/or feeding restrictions that they must follow. Most often, the average rotation restriction for cover crop species that fall into this “all other crops” category is between 12 and 18 months after treatment.
As just one example, the Flexstar label indicates: “Do not graze rotated small grain crops or harvest forage or straw for livestock.” Other labels have similar statements. The only way to be sure is to carefully check the labels of the specific herbicides that were used in your fields during the past growing season. (Many common herbicide labels can be found on the CDMS web site: www.cdms.net under the “services” tab.) Also, Dr. Vince Davis at the University of Wisconsin has put together an excellent fact sheet on this issue that can be accessed at the following website: http://wcws.cals.wisc.edu/new-fact-sheet-herbicide-rotation-restrictions-in-forage-and-cover-cropping-systems/. Producers that have an interest in utilizing cover crops for forage need to plan ahead and take note of the herbicide programs they intend to use during the summer and what implications these programs may have on using cover crops as forage.
REVISED: September 30, 2015