Issue No. 21, Article 6/August 17, 2007
Alternative Uses for Herbicide-treated Soybean Fields
Dry soil conditions across areas of Illinois have been detrimental to soybean growth. Double-crop soybean appear to have been particularly adversely impacted, but in some areas even full-season plantings are demonstrating signs of significant stress. Soybean farmers in these drought-affected areas may be considering utilizing existing stands for something other than seed harvest.
Grazing livestock or making soybean hay or silage are some examples of alternative uses for soybean. However, if a soybean crop was previously treated with or more herbicides, the herbicide label may prohibit these alternative uses.
Restrictions on soybean utilization exist for certain herbicides labeled for soil or foliar applications. For example, the restriction found on the Canopy (a soil-applied herbicide) label states "do not graze treated fields or harvest for forage or hay," while the Ultra Blazer (a postemergence herbicide) label states "do not use treated plants for feed or forage." Other product labels have restrictions based on application timing (Dual II Magnum prohibits grazing or feeding of soybean treated postemergence, but does not prohibit these practices if the product was applied preemergence) or specify a certain interval that must elapse between application and grazing, feeding, etc. (14 days must elapse between application of FirstRate and harvesting soybean for forage or hay).
Glyphosate-resistant soybean treated postemergence with glyphosate may be grazed or harvested for livestock feed not sooner than 14 days after application. However, certain glyphosate formulations restrict feeding treated soybean to livestock for 25 days following a preharvest application to non-glyphosate-resistant soybean varieties.
These examples illustrate there is no "blanket" answer to the question of using herbicide-treated soybean for livestock feed/forage. Before utilizing existing soybean stands for something other than seed harvest, be sure to check the labels of any herbicide(s) applied to a particular field.--Aaron Hager