Fuel saving strategies for grain dryers can have a big financial impact, according to Bill Wilcke, an engineer with the University of Minnesota Extension Service. Wilcke suggests these options for using less fuel to dry corn:

Store ensiled high-moisture corn

Rather than artificially drying corn, livestock producers can store some of their crop in silos or silage bags as ensiled high-moisture corn. Corn should be harvested at 25-30 percent moisture to get good fermentation.

Grain bin

Delay harvest to let corn dry in the field

Harvesting at lower moisture means less water removal by artificial drying is necessary. For corn that will be fed during winter, livestock producers who delay harvest until temperatures drop to near freezing might be able to avoid drying altogether.

If corn can be aerated in storage to keep its temperature near 30 degrees F, it can be safely stored at 18-19 percent moisture through the winter. The wet corn must be fed or dried by spring.

Reduce overdrying

Corn buyers usually want corn at 14-15 percent moisture. With proper storage management, corn will be safe in storage for six to nine months at these moisture levels. Some stored grain managers intentionally dry corn to lower moisture levels to reduce storage risk.

Overdrying corn is expensive, however, because it increases drying costs, especially when fuel prices are high. It also reduces the number of bushels that can be dried per day, and it reduces the number of bushels available for sale.

Switch to in-storage drying

If corn is currently dried at high temperatures and then rapidly cooled in the dryer, it's possible to save some fuel by cooling corn in the storage bin instead of the dryer. Almost no moisture is lost when freshly dried corn kernels are rapidly cooled immediately after drying.

But if corn is unloaded from a dryer while still hot and transferred to a storage bin where it is cooled slowly using the bin's aeration fan, the corn will lose one to two percentage points of moisture during the cooling process.

This means that if the final target moisture is 15 percent, the dryer can be unloaded when the corn reaches 16-17 percent moisture.

In-storage cooling saves the fuel that would be needed to remove the last one to two points of moisture. It also reduces the amount of time that corn spends in the dryer, which greatly increases dryer capacity.

Use dryeration

Dryeration is similar to in-storage cooling, except that corn is intentionally left hot (called steeping or tempering) for 4-12 hours.

During this period, moisture and temperature gradients equalize within freshly dried kernels. This enables the kernels to lose two to three percentage points of moisture during cooling.

Compared with rapidly cooling corn in the dryer, dryeration reduces energy use, increases dryer capacity, and results in better test weight and fewer cracked kernels.

It's best to transfer corn from the bin where cooling takes place to a different storage bin after the dryeration process to avoid possible problems from condensation along the inside walls of the cooling bin.

Consider natural-air drying

Natural-air drying is an in-storage drying process that uses bins equipped with fuly perforated drying floors and fairly large fans (approximately .75 to 1.0 fan horsepower per 1000 bushels of corn for bins that are not deeper than about 18 ft.).

Natural-air drying works well in the upper Midwest, but harvest must be delayed until corn moisture drops to about 22 percent in the field.

Drying requires several weeks of fan operation. In many years, drying is not completed before winter. In that case, corn is kept cold during winter, and drying is finished in early spring.

Although natural-air drying uses no natural gas, it does use an average of about one kilowatt-hour of electricity per bushel of corn to operate the drying fan.

Use combination drying

If you don't like some of the limitations of natural-air drying, you can partially dry corn to about 20 percent moisture in a heated-air dryer and then finish drying it in a bin equipped for natural-air drying.

Combination drying allows earlier harvest than natural-air drying, but uses less fuel and produces better corn quality than complete heated-air drying.

Contact your Ag Services representative to learn about energy-smart grain drying