When it comes to corn harvest, two factors matter most: yield and moisture. Often, there’s a trade-off; longer maturity hybrids may deliver more bushels but are typically wetter at harvest. The question then becomes: Is the extra yield enough to pay for additional drying?
On average, it takes about 0.02 gallons of propane to remove one point of moisture per bushel of corn. Using that, you can estimate drying costs with a simple formula: bu/A × points of moisture to remove × 0.02 × propane cost ($/gal) = $/acre.
For example, at 150 bu/A, it takes 2.8 bu/A to offset the cost of drying grain that’s two points wetter, assuming propane at $1.50 per gallon and corn at $3.25 per bushel, as shown in the illustration. Keep in mind that energy isn’t the only cost. You must consider the cost of equipment wear, handling and shrink.
Best Practices for Managing Grain Moisture
An accurate moisture tester can be one of the most important tools on the farm. Even a half-percent error in grain sold can cost more than the price of a reliable tester. Calibrating against the buyer’s tester ensures accurate and agreed upon measurements.
Grain dryers should also be checked frequently. Manual dryers require more hands-on attention, while automated systems still rely on calibration to stay accurate.
When choosing between grains that are slightly too wet or too dry, selling grain that is too dry is usually more costly. That’s because over drying results in losing the weight represented by the moisture differential. Selling grain too wet may result in drying costs (some of which would have been spent to dry the grain on-farm anyway) and shrink, but weight won’t be lost.
Over drying can be especially costly when grain is stored long term. Different buyers, such as ethanol plants or wet mills, often have different moisture requirements. Knowing the end market is the first step to hitting the right target.
Grain moisture can be adjusted by blending or aerating to meet the maximum allowed, often 15.5 percent. In some cases, electronic control systems that run fans during ideal weather conditions can help. Hoverer, increasing grain moisture can take months, further emphasizing the importance of not over drying.
Each fall, Ryan Bates, Pioneer Field Agronomist in Wisconsin, samples multiple hybrids once a week from black layer until harvest. Three ears of each hybrid are hand-shelled, mixed and tested three times for moisture and test weight, then averaged and recorded over a four- to five-week period.
“The data helps track how different hybrids dry down locally and provides timely insights for harvest decisions,” he said.
The results highlight the value of hybrid selection and local drydown information in managing harvest and improving profitability.
Favorable weather with warm, sunny days and steady winds can contribute to corn drying down naturally. As a result, corn can reach ideal moisture levels. Test weights and harvest can be completed quicker under favorable conditions while minimizing dryer costs.
The Bottom Line
Grain drying and storage can make or break profitability. By fine-tuning the approach — whether by investing in accurate testers, calibrating systems or managing storage — bushels, and therefore profitability, can be preserved.
