Posted on February, 17, 2025 at 10:14 am
There’s good news when it comes to on-farm grain storage this year.
“Overall, we had a good growing season,” says Charlie Hurburgh, an Iowa State University Extension grain-quality specialist. “The crop was ahead of schedule and developed more completely than its preceding years.”
This transferred into excellent test weight for corn: an average 58 pounds per bushel, according to surveys taken by the Iowa Department of Agriculture and Land Stewardship.
“Test weight is the best indicator of storage quality, and we are in good shape for test weight for stored corn,” Hurburgh says. Last fall’s dry weather also led to much corn that didn’t need drying, often falling to 14% or lower moisture at harvest.
Still, successful corn storage hinges on proper grain cooling.
“If you didn't do that, you might have some problems if you put corn in your bin when it was 70 or 80 degrees,” Hurburgh says. “Dry grain can spoil and go out of condition if you don’t cool it.”
ISU recommends cooling grain anytime the average air temperature is about 20 degrees F cooler than the grain temperature. Repeat this cooling cycle until the grain temperature is 30-40 degrees F for winter storage.
Hurburgh notes that the allowable storage time (shelf life) of corn almost doubles by reducing grain temperature from 50 to 40 degrees F. For example, 17% corn has a storage life of 5.3 months at 50 degrees F, but its storage life increases to 9.4 months at 40 degrees F.
Soybean storage properties are similar to corn that is 2% drier (15% soybeans store like 17% corn).
However, determining bin temperature often is difficult for most on-farm storage systems, as they often are not equipped with the temperature monitoring that elevators use. Removing the bin’s center core of corn can help prevent storage losses, Hurburgh says.
“One challenge is that corn harvested last fall during dry weather also had more broken kernels and fines than normal,” Hurburgh says. “In terms of not breaking corn, combines work best harvesting corn between all 17% and 22%. When you harvest corn at 14% moisture, you will get more broken kernels. As corn gets drier, it is more brittle.”
Removing corn in the bin’s center core can nix the broken kernels and fines that block airflow and create moisture pockets.
“Draw out enough loads until you see the grain collapse toward the side,” Hurburgh says. “The best way to manage this is to have some corn and beans sold for fall delivery (of grain in the bin’s center) into town.”
Good news also exists for soybeans, although late-summer drought posed some harvest complications. “If we had a quality problem for last year’s soybeans, it would be that it was too dry,” Hurburgh says.
Soybeans were smaller as a rule, although oil and protein content are adequate for processing, he adds.
Dry weather spurred some soybeans to dip all the way down to 6% moisture at harvest.
“One point of moisture at soybeans is worth about 12 to 14 cents a bushel in water weight that could have been sold,” Hurburgh says. “So going from 13% moisture soybeans down to 6% represents nearly a dollar-per-bushel loss.”
He notes that some devices are marketed to run fans at strategic times and ventilate with humid air to restore soybean moisture.
Much care, however, needs to be taken if this is done.
“Putting water back through high-humidity air is much slower than drying [excessively wet soybeans],” Hurburgh says.
Remember that soybeans also can swell during this process.
“What can happen is that swollen soybeans can place so much pressure inside the bin that bolt heads pop out,” he says. “Aerating to put moisture in the bin from the bottom up is a difficult proposition. It needs to be done carefully and with a lot of monitoring.”