If you think you may have grain storage challenges and your answer is aeration, think again says Bill Wilcke.
"Aeration is the best weapon for keeping dry, stored grain in good condition during cool months, but should be avoided during warm weather," says Wilcke, an engineer with the University of Minnesota Extension Service. "During the aeration process, the temperature of stored grain is gradually brought to the temperature of the air moving through the grain."
The best time to aerate grain is when the outdoor temperature is less than about 50 degrees, according to Wilcke. This allows the grain temperature to stay low enough so molds and insects don't grow very fast, avoiding grain spoilage. "If grain is aerated when the outdoor temperature is 60 degrees or higher, the grain is warmed to a temperature where mold and insect growth and reproduction are very rapid," he says.
To manage stored grain during warm weather, first make sure the grain is dry, clean, uniformly cool, and free of insect and mold problems. Grain that is damp, contains large amounts of fines and foreign material, or has hot spots or obvious mold or insect problems should not stay in summer storage. Wilcke says it's best to correct the problems or feed or sell the grain before the weather becomes too warm.
After summer weather arrives, Wilcke says to check the grain frequently-maybe as often as every week or two. If grain storage problems develop and there are times of the day when the temperature is less than 60 degrees, aeration may be feasible. "Try aerating the grain by using a fan that is controlled so that it only operates when the outdoor temperature is less than 60 degrees," Wilcke suggests. "You could control the fan by switching it on and off manually, by using a simple thermostat or by using a sophisticated microprocessor-based controller."
If there isn't enough weather cooler than 60 degrees available for aerating the grain and it starts to heat due to mold and insect activity, raise the temperature settings for fan operation, says Wilcke. Then make immediate plans to move the grain out of storage.