Aeration of Corn and Soybean after drying

 

Dried corn and soybeans are meant to be aerated immediately after they are filled in the permanent storage structures or the storage bins for an effective grain temperature monitoring system. In upright bins, there is a need for aeration systems that must be designed for generating nothing less than 1/7 to 1/10 cubic feet of air per minute per bushel (CFM/bushel). This will allow the cooling fronts to move through the corn and soybean mass in a minimum time period of 105 to 150 hours.

When the depth of the grain when storing exceeds 50 feet (15 meters) such as in the case of the tall concrete silos, then the airflow rates of 1/20 to 1/40 CFM/bushel should be selected to overcome extreme static pressure and horsepower conditions using the EndZone Fan Controls. These rates will help in resulting in the cooling fronts to move through the grain mass of corn and soybean for a minimum of 300 to 600 hours. However, when the grains are stored in flat storage sheds, then the airflow rates that are lower than 1/10 CFM/bushel should be used to reduce the in-floor and above-floor aeration duct sizes.

During the time of late October, running fans are operated using EndZone Fan Controls on corn and soybean grains in the regions of the midwestern U.S.  It is helpful in cool the grain to below 50°F (10°C) by automatic operation of the fan. By late November, it is recommended that the temperature levels should be dropped below 40°F (5°C). Whereas, by late December, the temperature of corn and soybean must be cooled down to about the freezing point that is 28-36°F (-2-2°C). And when it comes to the months of January and February, it is absolutely not necessary to run aeration fans until and unless there are signs of rising temperature observed because of the self-heating of the stored grain.

Excessive aeration of the stored grain that is below the recommended safe storage moisture content will result in additional shrink loss for corn and soybeans. As compared to the current low prices and thin margins of corn and soybean, the losses from excessive cost of energy and unwanted shrinkage of the grains can be substantial. Shrinking of the corn by 1 percentage will result in a cost of about 4 cents per bushel of weight loss and about 0.5 cents per bushel in energy cost. Whereas for soybeans, there would be an additional cost of about 10 cents per bushel due to weight loss and about 0.5 cents per bushel in energy cost.

When the corn and soybeans sustain in good condition at the time of storing and the grain mass has been cored, then it is suggested that the aeration fans should be sealed even before the arrival of the spring season. Operating the roof exhausters of the aeration fans after the sun is down should be enough to remove warm temperature and the relatively high humid air from the headspace. This will prevent the development of condensation under the roof as well as on the grain surface.