If your corn fields have been one of the lucky few to receive rain recently, the added moisture can actually increase the risk of nitrates in the plant.
“The first significant rainfall to moisten the upper soil profile will stimulate microbial activity, causing a flush of nitrate nitrogen to be released into the soil system,” says Kurt Steinke, an Ag Bio Research scientist with Michigan State University. “As corn plants then begin to recover from drought conditions, the plants take up nitrate at rates greater than they are fully able to assimilate, resulting in the accumulation of nitrate within the plant.
“This process of intense nitrate uptake and accumulation may require up to two weeks following significant rainfall to fully assimilate nitrate in the plant,” he says. “In order to minimize the risk of nitrate poisoning, a general rule of thumb is to wait at least two weeks before harvesting corn.”
For Steinke’s complete report, click here.