Source: University of Wisconsin Extension
The drought of 2012 has caused havoc on crops during the summer and into the fall, prompting many growers to consider the harvesting cover crops such as rye or wheat or even buckwheat as an emergency forage crop.
Some of this interest is even being driven by agencies that have lifted other restrictions, including recent assistance put in place by USDA NRCS to help establish cover crops including the allowance for grazing and harvesting in some situations and The USDA changing crop insurance rules for 2013.
But Vince Davis, University of Wisconsin-Extension weed specialist at UW-Madison said there’s quite an important distinction as to whether those cover crops are left in the field or harvested for forage, as well as what type of herbicide has been used on the crop.
“A cover is a crop planted that is not harvested but only grown for environmental benefits and all of the crop residue stays in the field. As soon as the crop residue, or biomass, is removed from the field to be fed, it is then considered a forage crop,” he noted.
“Growers need to take note of the herbicide labels and their cover crops; and realize that these restrictions need to be followed,” Davis said. “Herbicide labels that are used in our traditional corn and soybean systems all have restrictions on when crops can be planted following the use of those herbicides in those systems. Once that cover crop is harvested it’s considered a forage crop and, therefore, restrictions on a label need to be followed.”
When a herbicide is registered for use, the herbicide registrant must prove to the Environmental Protection Agency – through extensive research – that there is no threat of harmful residues in succeeding crops if the product is used according to label. If a succeeding crop species is not specifically examined for residue safety, then the time lapse on the label is set to a time at which the herbicide has shown to dissipate in the soil to a point when it will not affect succeeding crops. This default time period is often 18 months to two years.
Davis noted that some potential consequences of not following herbicide labels could be herbicide residues that come back into the food chain and into meat or milk products.
He recommends that growers make certain they know what herbicides, and all pesticides, have been used in their corn and soybean systems and that they follow the label for rotational restrictions of those products before they harvest a succeeding crop for a forage.
“Growers in conventional agriculture do already care very much about producing high quality and safe products in a sustainable manner,” Davis said. “However, because of the drought conditions and the haste of trying to fix a situation with unconventional practices, growers need to be sure they continue to make informed decisions and not overlook herbicide regulations.”
For more information about using cover crops as forage, visit UW-Extension’s drought website here.