Nitrate Levels Skyrocketing in Spring Grains
June 24, 2021
By PR Extension Office
In a year where forage is short in supply and vitally important, nitrate levels have tested very high in samples of spring grains, according to Powder River Extension Agent Mary Rumph.
“Many producers are trying to make hay before the crop either burns up or is eaten up by grasshoppers,” commented Rumph. “Right now, the crops are testing too high to even graze safely,” added Rumph.
High levels of nitrates in cereal grain are often present under drought conditions. The roots of growing plants will continue to take in nitrate nitrogen; however, normal plant metabolism which convert nitrate to protein is disrupted and high nitrate levels accumulate. Any time the plant is stressed, nitrate levels can increase. This can also occur as the result of a hail storm.
At normal levels of nitrate in the soil, the nitrate content is usually higher in young immature plants, but decreases as the plant matures. The nitrate is usually highest in grain hay harvested before the dough stage of development. As the plant approaches maturity, the nitrate content usually decreases to well within safe feeding levels. Waiting until the soft dough stage can significantly decrease nitrate levels, however this year, that might not be an option. Winter wheat is much less likely to accumulate nitrate compared to spring grains. So far, winter wheat samples have tested at safe levels, according to Rumph. Oats tend to accumulate nitrate more than most other cereal forages.
“We are receiving immature samples at the Extension Office that haven’t even began to head or fill with grain,” said Rumph, “unfortunately, most have shown extremely high nitrate levels, creating a dilemma for producers. Great caution will be necessary in utilizing these crops,” said Rumph.
Under “normal” conditions, nitrate levels can be lowered by avoiding cutting or grazing when nitrate concentrations are at peak levels. Peak levels occur in the morning; delay haying or grazing until the afternoon on a sunny day. Under the current conditions of high heat and low moisture, there might not be a “safe” time according to Rumph.
At the Extension Office, forage samples can be screened for nitrate levels. The screening test is a good place to start and can indicate whether more time is needed for the crop to mature. Samples of standing crops should contain approximately 20 plants (taken randomly by traversing in a zigzag pattern across a field) cut off about 4 inches above the ground. If the screening test indicates a high level of nitrate, a sample can be sent into the MSU Analytical laboratory for further testing. For more information on nitrate toxicity of forages, go to http://www.msuextension.org/ powderriver or contact the Powder River Extension Office at 436-2424 if you have questions.