Maintenance and Inspection
• Make sure that perforated ducts are clean and transitions and manifold ducts have no holes. Air takes the path of least resistance, and even a small hole will change your distribution.
• On an updraft (positive) system, make sure the exhausters are sized and working properly. This will prevent “raining” inside the bin.
• Undersized or worn-out drying systems and equipment should be upgraded or replaced well before harvest season. Equipment maintenance and pre-season servicing reduces untimely breakdowns during the harvest process.
• It’s critical that aeration fans, roof vents, and roof exhaust systems are matched to work together in conjunction with the size of the storage bin and the type of commodity being stored.
Temperature Monitoring and Aeration
• Grain is a living organism that has a natural respiration process. The respiration process produces both moisture and heat. Mold spores in the grain become more active the warmer the temperature; this is one of the reasons why temperature control is so important.
• Poor weather conditions, as well as late and uneven crop maturity, have the potential to create havoc for your grain drying system.
• Establish a conditioning plan before grain is stored so that you know the starting moisture level needed to reach your desired shelf life.
Base the plan off the longest time you intend to store the grain. If you consider the average storage temperature month by month, you can use shelf life charts to determine the percentage of shelf life remaining. This is most important when you intend to store the grain for a long time or have a warmer climate.
• Have a proper system in place to actively monitor all grain temperatures in the bin. Various monitoring options are available, including manual, automated, and wireless systems that can pinpoint hot spots and help to eliminate moisture migration within the bin.
For bins with temperature cables, check the grain temperature in the bins every week during the initial fall cooling and at least every two weeks through the winter.
For bins without temperature cables, check the top surface of the grain mass every few weeks in the winter for crusting. With the aeration fans operating, check for odor in the air exhausting from the grain.
• Cool the grain as much as possible without freezing. In the spring, gradually warm the grain in 15- to 20-degree increments to about 50 degrees F.
• Try to run aeration fans when the outside ambient temperature is within 15 degrees F of the grain temperature.
• You may leave grain cold only if it will be delivered before June. But make sure you seal the fan entrance(s) and discharge opening to keep out humid air.
If not leaving the grain cold or you are storing into June or after, maintain grain temperatures within 10 to 15 degrees F of the outside air to avoid grain deterioration caused by condensation developing on grain bin interiors. Consult your local agriculture university for recommendations, as conditions vary widely by location.
• Check dry grain in storage every week when average ambient temperatures are on the move. Watch for grain that is crusted or wet and evidence of frost or moisture on the underside of bin roof panels, as this may be an indication of moisture migration that should be addressed with aeration immediately.
Grain Handling
• Proper conditioning of grain starts with the use of a high-volume, commercial-grade grain spreader that can spread out fines in corn and bury the pods in soybeans.
Using a high-quality spreader allows you to level off the grain mass in your bin. Being off even as few as a couple of rings from side to side will affect airflow through the grain.
• Visually inspect and adjust grain spreaders to be certain that fine distribution and grain levels are correct when grain is entering a bin. Well-adjusted grain spreaders and proper coring will ensure air movement is uniform.
• Make sure the grain in storage is cored properly. This will promote better airflow through the grain mass. When filling a bin, pull a cone 10 feet wide at the top every 10 feet of depth to reduce fines.
• Grain spoilage is potentially greater with high-moisture foreign matter at the center and a reduced airflow.
Grain Drying
• In-bin drying can bring down moisture only so many points, and in-field drying has its limitations, as well (such as field loss). So, in some cases, the best option might be to look at utilizing a high-temperature drying system. Proper conditioning before and during the storage process is imperative if you want to prevent loss from spoilage.
• Hot corn dropping from the dryer can cause condensation problems inside cooling storage bins. In addition to condensation, wet fines, debris, and foreign matter in the center of the bin can cause uneven airflow between the center and sidewalls of the bin.