Grain storage is a component of a grain marketing plan. It allows the farm manager to plan for and take advantage of price rallies. Regardless of when grain is sold, it must remain in good condition and quality to get the best price. In today’s column, OSU Extension educators Bruce Clevenger (Defiance County) and Curtis Young (Van Wert County) provide information about grain bin monitoring to maintain grain quality.
Two factors related directly to the stored grain condition are grain moisture content and grain mass temperature. The general idea is the longer the grain is stored, the lower the grain moisture content. If corn was moldy at harvest, it should be dried to 13% regardless of the length of storage. Without mold, corn should be dried down to maximum of 15% moisture content if stored from harvest to January 1, 14% if stored from harvest to early Spring (say April 1), and 13% if stored past April 1 and carried into the warmer spring and summer months. Soybeans are similar at 13%, 12%, and 11%, respectively. Grain mass temperature is also important. Fortunately, Ohio farmers can effectively take advantage of fall and winter temperatures by chilling the grain to 32 to 35 degrees Fahrenheit from harvest by mid-December.
After the bin is loaded, the center core of grain should be pulled from the bin. Fine material will naturally load near the center of the round bin and negatively impact the aeration efficiency. When the bin is loaded, the grain mass is typically pointed up like a cone, after the core is pulled (unloaded) the cone is flattened or inverted as a depression. After coring the bin, the grain mass should be leveled flat for most efficient aeration. If the core grain is found to be containing fine and foreign material, it should be cleaned and stored or sold off farm with a potential discounted value.
The aeration system on bins will either move air from the top and exhaust out the bottom or move air from the bottom and exhaust air out the top. Whichever direction, the cooling front needs to move completely through and out the grain mass. Monitor the exhaust end for the final desired moisture and temperature. Consider sealing off fans when they are off to prevent migration of moisture and temperature into the cool, dry grain.
Bin conditions should be monitored bi-weekly until the temperature reaches 32 to 35 degrees and then monthly through the winter months. Record the grain moisture and temperatures at multiple locations at the top of the grain mass. Just know that the center and north vs. south sides of the grain bin may have different grain moisture and temperatures and they are worth monitoring and recording them separately. Be aware of smells when entering the bin. Look for condensation or mold on the bin walls and roof. Grain that is going out of condition will often have a moldy smell while moisture and mold is a sign that conditions are not favorable for grain storage.
The grain handling facility should be clean before and after the grain is loaded. The bin, equipment and storage area should be free of grain spills, weeds and excessive vegetation. Starting with cleaned grain, stored into a clean bin will prevent problems. Questionable grain due to high levels of broken grain, fines, foreign material, or mold should be stored separately or moved out the quickest compared to other higher quality grain.
Insects can be monitored early and throughout the storage period. For insect activity in the grain mass, a passive, pitfall trap can be used. One particular pitfall trap is the Storgard WB Probe II by Trece. It’s approximately 18 inches long with a diameter of 1.25 inches. The pitfall trap is inserted into the grain mass with the tapered end first until the top of the trap is even with the grain surface. Multiple traps are used simultaneously with one in the center and 2 to 4 traps around the outside of the bin walls no closer than 24 inches from the bin wall. The traps remain in the grain for 3 days and then removed. The tapered end of the trap spins off to reveal where fallen insects are collected.
The insects can be properly identified to determine if they are primary or secondary insect pest for stored grain. Primary insects can do direct damage to whole grain such as weevils or Lesser Grain Borer, while secondary insects feed on mold, cracked and damage grain such as Foreign Grain Beetle, Red and Confused Flour Beetles. A grain bin of whole undamaged kernels stored at the proper temperature and moisture is the key to preventing the secondary feeders.
While grain bin management is important, safety in and around grain bins is an absolute. Climbing and entering a grain bin can be extremely dangerous due to falls or grain entrapment. Every entry to a grain bin needs to be pre-planned to identify hazards. Proper safety equipment is essential for all involved. Entry should never be made without a plan that involves informing a fellow farm employee or family member. Safe entry will ensure a safe exit.