With warmer temperatures across most of the Corn Belt, now is the time to check stored grain. “This year there is more wet corn in storage, and there has been a rapid weather switch from cold to warm,” says Charles Hurburgh, professor in charge of the Iowa Grain Quality Initiative at Iowa State. “Check now and often to prevent future problems.”
Check temperatures
“If good practices were followed through the fall and winter seasons, grain temperatures should be in the 30s or below,” advises Hurburgh. “If there is a temperature rise in the grain, mold activity is starting and the aeration or drying fan should be operated.
“Temperature cables are an important part of storing grain because they give you a safe way to monitor the grain.
During the next few months, you will want to warm the grain up, although to what degree varies. The old-school recommendation was to warm the grain to within 10° to 15° of the outside temperature. For the last 20 years, the recommendation has been to keep the grain cool, about 40°F., during spring and summer. Some are now suggesting warming the grain up to 50°F. for storage over summer.
“If you are going to sell by June 1, you can leave grain cold,” says Gary Woodruff, GSI. “If you’re going to bring it up to temperature for a later sell, I’d stop at 50°F. to 60°F.”
Ken Hellevang, North Dakota State University Extension Engineer, recommends keeping the grain near 40°F. “Part of the reason for the lower temperature trend the last several years is that insect infestation and mold growth are going to flourish in the 70°F. to 90°F. temperature range,” he explains. “If you can keep the temperature below 50°F., the insects are dormant.”
It’s critical to check grain frequently during the warmer months. Check the moisture content and keep an eye out for insects.
“In warmer temperatures, you can go from one or two insects to a major infestation in a period of two to three weeks,” says Hellevang. “If you aren’t checking every week or so, you aren’t able to take corrective action. You will end up reacting to major problems.”
Check moisture levels
“Grain moistures last fall were above average, and there are many bins with corn moistures in the range of 16% to 20%,” says Hurburgh. “This wetter grain will spoil quickly if grain temperatures rise.”
Headspace in the bin will warm up first, which can lead to condensation. Running roof fans will help take the moisture out without having to warm up the grain.
For bins with wet corn, low-humidity, moderate-temperature days are good for air drying. “Humidity typically goes up in May and June, so it will be best to have the grain dry by then,” adds Hurburgh.
When you need to run drying or aeration fans, be sure that you’re operating the fan for long enough to change the temperature in the entire bin. This will take 15 hours for a drying fan with 1 cfm/bu flow rate and 150 hours for an aeration fan with 0.1 cfm/bu.
