To avoid nitrate toxicity, test forages before feeding to livestock and follow feeding guidelines in the Animal Nutrition section that follows. In addition, consider the amount of nitrates in the water supply, as this can add to a nitrate toxicity problem. Usually the potential for nitrate poisoning is eliminated after ensiling, although testing the silage before feeding to livestock is strongly recommended. Do not chop the corn for one week after a rainfall occurs. If possible, raise the cutter bar to leave 10 to 12 inches of the lower stalk in the field.
Nitrates tend to accumulate in the lower portion of the stalk on drought-stressed corn.
Do not graze the stalks due to the high nitrate content and the potential toxicity problems. Data from Kansas State indicates that bacterial inoculant and NPN supplements are compatible, however, some caution should be advised regarding application techniques. If you are using urea as a NPN source, both may be applied to the forage at the blower. If you are using a cold-flow anhydrous ammonia system, you must apply the ammonia at the chopper and the inoculant at the blower to prevent destruction of the inoculant. When a forage that is high in nitrates is fermented, various nitrogen oxide gases are formed which are highly toxic to humans and livestock.