The highest concentration of nitrate accumulates in the lower third of the plant stalk or stem. It is progressively diluted toward the top of the stem. Very little nitrate is found in the flowers or seed. The effects of nitrate levels of forage, feed and water are additive and both must be considered when evaluating a nitrate problem. Nitrates may reach dangerous levels in ponds, shallow wells or streams that collect drainage from manure, highly fertilized fields or industrial waste.
Deep wells are usually safe sources of water.
No safety standards have been set for water, but it has been suggested that up to 100 ppm of nitrate nitrogen in water should be safe if cattle are consuming an adequate ration that is free of nitrates. This is 10 times the safe level set for humans. An analysis of forage is necessary to know with certainty that nitrates are present at toxic levels. A field test can indicate if nitrates are present, but suggestions for diluting feeds are based upon a more precise laboratory analysis of the forage. When submitting a laboratory test, be sure your sample accurately represents your feed.