How Herbicide Labels Restrict Using Cover Crops as Forage
Many growers have planted or are planning to plant cover crops after grain harvest. Remember, however, that grazing these cover crops or harvesting these fields for forage is likely illegal.
The problem stems from the herbicides used in the previous crop. With the exception of glyphosate, most herbicides commonly used with annual crops in Nebraska have rotational restrictions limiting the length of time until other crops, including forage crops, can be planted in that field. It doesn't matter whether the previous crop was seed corn, hailed out, chopped for silage, or combined normally.
If the label doesn't specifically mention approval of your cover crop or each of the species in your cover crop cocktail, the rotational restriction automatically becomes the maximum interval, which usually is 18 months.
If you ignore this restriction, you're breaking the law and potential penalties are severe. Your livestock could be quarantined or destroyed.
These label restrictions exist because sufficient herbicide residue tests have not been conducted to determine a tolerance level for the herbicide on that specific cover crop. You or other farmers may have used this cover crop forage with no ill effects in the past, however, it's important to recognize that that use is illegal.
Extension Forage Specialist