NDSU Extension - Mercer County


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Corn Drying Methods

corn, corn drying and storage
Corn Drying Methods

Photo: Liz Stahl

Submitted by Craig Askim, Extension Agent/Agriculture and Natural Resources

Corn harvest is in full swing but due to recent snow, harvest has been delayed.  Once conditions improve, harvest will start again but corn may be wetter than normal. Most producers know that drying will likely be necessary to prevent spoilage. Following are some important things to remember when drying corn.

Corn above 21 percent moisture should not be dried using natural-air or low-temperature drying because the drying capacity of natural-air and low-temperature is extremely poor at temperatures below 35 to 40 degrees. Little drying typically is possible using a natural-air system after about November 1.

When outdoor temperatures average near or below freezing, cool the corn to 20 to 25 degrees for winter storage and finish drying in April to early May. Limit the corn depth to about 20 to 22 feet to obtain an airflow rate of 1 to 1.25 cubic feet per minute per bushel. Turn fans off during extended periods of rain, snow or fog to minimize the amount of moisture the fans pull into the bin.

Using the maximum drying temperature that will not damage the corn increases the dryer capacity and reduces energy consumption of a high-temperature dryer. Removing a pound of water requires about 20 percent less energy at a drying air temperature of 200 F than at 150 F. Follow the dryer manufacturer’s recommendations, but generally, recommended temperatures when drying corn are 210 to 230 F.

Excessively high drying temperatures may result in a lower final test weight, increased breakage susceptibility, and may increase browning of the kernels.  A cross-flow dryer that moves corn from the inside to the outside of the drying column, varies the corn flow rate across the drying column or varies the corn’s exposure to the drying air is more likely to maintain corn quality. 

Removing debris that accumulates on or in a dryer is more critical when outside air temperatures are cold because condensation can develop on the dryer, creating a wet surface on which debris can collect. The debris may reduce airflow through the dryer, decreasing the dryer’s capacity and creating a fire hazard.

More mechanical damage occurs when harvesting high-moisture corn, which affects the storage life of the corn. Dry low-test-weight corn and corn with more damaged kernels to a percentage point lower in moisture content than normal.

Check immature and damaged grain more frequently, and do not put immature or damaged corn in long-term storage.

Working with high-moisture corn can be hazardous so become informed of the hazards and recommended safety practices.  Have someone present at all times and spot check on a regular basis when the dryer is in operation. Do not become a fatality.

Source: Kenneth Hellevang – NDSU Extension Agricultural Engineer

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