In a year met with unique corn harvest and storage issues, paying extra attention to grain bin safety has become of utmost importance to farmers, says Matt Roberts, Purdue Extension grain storage specialist.
"The biggest grain bin safety concerns this year are related to moldy corn," Roberts says. "The molds we are concerned about develop when corn is stored too wet – above 15% moisture – and also can develop if moisture enters the storage structure through leaks or downspout condensation.
"Also, kernels of grain damaged by the field molds we experienced this year, and the increased broken kernels and fine materials that resulted from this year's high harvest moistures, are more susceptible to storage mold growth than are healthy, undamaged kernels."
Damaged and moldy grain often clumps together and can cause clogs, or other in-bin issues that require farmers to find a solution – something Roberts says they should do from outside the bin, if at all possible.
"As moldy corn is drawn out of the bin, it can clump together and clog the center well, requiring farmers to find a way to break up the clumps," Roberts says. "The danger here is that farmers may be tempted to enter the bin to try to rectify the situation."
In addition to clogging center wells, molds also can cause corn to bridge across the top of a bin.
"Often times moldy corn crusts at the top of the bin, and when a farmer goes to unload the bin, the crusted grain causes a bridging phenomenon," Roberts says. "If the grain has been drawn out from under the crusted layer and a farmer walks on top of that grain, the bridge can collapse and the farmer can become entrapped under that grain."
Another issue with corn molds is that they cause grain to stick to the sides of the grain bins. Roberts says the safety concern comes when farmers climb into the bin to try to probe the stuck grain from underneath. In this scenario, when grain does break loose, it can avalanche, also entrapping the farmer.
"We recommend that farmers try to probe clumps – both on the walls and in the center well – from the outside of the bin to avoid becoming entrapped," Roberts says. "However, if farmers do decide to enter bins they need to make sure all of the equipment, including augers, are not only turned off, but also locked out in case a contractor were to come and try to unload those bins without knowing someone is inside.
"It's also essential to have an observer on the outside of the bin to pay attention to what's going on outside and to keep an eye on the person inside the bin."
Purdue Agricultural Engineer Richard Stroshine says that in the case of clogged bins, farmers also should avoid opening side wells for fear of bin collapse.
"If a bin is plugged up, one thing farmers don't want to do is open a side well," he says. "What happens is that creates an unbalance of forces in the bin, and if farmers start drawing corn from the side well it can actually cause the bin to buckle.
"There is some equipment for loosing up bins if there is a problem. If farmers find themselves in a really difficult situation, contacting one of the companies that makes this sort of equipment can help them determine the best approach to solving the problem."
Safety harnesses are another way farmers may try to increase grain bin safety, but Roberts says most bins are not designed to hold farmers from inside the bin with a harness.
"Farmers who have harnesses need to make sure they are approved for grain bin use, and they need to be aware that other than helping rescuers locate them in an emergency situation, harnesses don't really help with entrapment," he says. "Harnesses should definitely be used when farmers are working up high, outside the bins, however, to prevent falls."
Roberts also says that managing aeration correctly and monitoring bin conditions can reduce some of the safety concerns.
"Farmers should check their bins every two weeks," he says. "We recommend they let the fans run for about five minutes, then climb up, open the door and smell for mold.
"If farmers are warming grain as the outside temperatures come up, they should make sure not to come above 50° F, because anything higher is going to promote mold and insect growth."
More information about dealing with the fallout of this year's wet harvest is available on the Purdue Extension Managing Moldy Corn Web site.