Some calculations can help producers get a handle on grain drying costs, a South Dakota State University specialist says.
SDSU Extension Farm Machinery and Safety Extension Specialist Dick Nicolai says previous years' farm records may be a good place to start.
To calculate the cost of drying, producers should consider the cost of gas, as well as cost of electricity to run fans (relatively small on a per bushel basis for gas-fired dryers), labor to manage the drying system, and depreciation, taxes, insurance, repairs, and maintenance on the drying equipment.
"Gas use by gas-fired corn dryers varies widely with type of dryer, how the dryer is managed, corn moisture level, and weather at the time of drying," Nicolai says. "The best source of information on gas use is your own records for gas use, bushels dried, and moisture removed."
A very rough estimate of gas use for gas-fired drying is 0.02 gallons of LP per bushel per percentage point of moisture removed. For dryers that use natural gas, the equivalent number would be about 1840 cubic feet of gas per bushel for each moisture percentage point removed, Nicolai says.
When five percentage points of moisture are removed (for example from 20 percent moisture down to 15 percent moisture, wet basis), you could expect to use 0.1 gallons of LP per bushel (5 points x 0.02 gal per bushel per point). If LP gas costs $0.50 per gal, the gas cost would be about $0.05 per bushel. But if you need to remove ten percentage points of moisture and gas costs10 points x 0.02 gal per bu per point x $1.00 per gal).
For more information on grain drying and storage, also see "Grain Drying, Handling, and Storage Handbook" (MWPS-13), a publication from the Midwest Plan Service. The book is available through South Dakota State University's Department of Agricultural and Biosystems Engineering or online at http://abe.sdstate.edu/MWPS.