Even though grain went into the bin at normal moisture levels, be sure to check those bins. Ohio State University Extension offices have received reports of bins of grain sweating to the point of moisture dripping from the roofs and down the sides of the bins. With soybeans coming off so dry and the idea that beans are easy to store, some farmers may be forgetting a key factor: All grain needs to be cooled down to avoid condensation. Yes, the soybeans may have been binned at 9-10% moisture, but they were harvested at 80° F – setting up an ideal condensation scenario when outside temperatures dip into the 40s and below.
Much of the farm storage of soybeans is in bins without stirrators and some of those bins may have inadequate ventilation, which could cause some serious problems with temperature and moisture management.
Farmers are more likely to track grain condition in corn bins but once again may be lulled into thinking if they did not need to dry it, why put air on it? Remember that more stored grain goes out of condition because temperatures are not controlled than for any other reason.
Since grain is a good insulator, it does not cool uniformly as outside temperatures drop. Air near the bin wall cools and settles toward the bin bottom creating convection currents. The air then rises up through the warm grain picking up moisture in the form of water vapor. The air continues to move toward cooler grain near the surface, where the moisture condenses and can cause spoilage.
The most common location of wet or spoiled grain is at the top-center of the bin. Another location for storage problem symptoms is the grain near the bin wall, often the colder north wall.
PLEASE keep in mind your stored grain is like money in the bank, but only if its condition is properly maintained. For more information of corn storage molds, see the article by the same name in CORN Newsletter 2010-33.