Getting the Combine Ready For Fall Harvest

Before you know it, the rush of fall harvest will be here. Ensuring a smooth harvest season depends a lot on your combine – the more efficient it is, the fewer breakdowns it’ll have, which can have a real bottom-line impact in lost yield and productivity.

To get off on the right foot, we asked Mark Hanna, extension agricultural engineer at Iowa State University, to share his thoughts on prepping the combine for harvest.

For openers, Hanna suggests growers follow the recommended maintenance schedules for their combines, changing oil and filters and lubricating the combine as close to regularly scheduled intervals as possible.

“Proper combine operation is a trade-off of gathering, threshing and separating well enough to limit field losses due to the machine, but not being so overly aggressive in threshing and separating as to adversely affect grain quality by scratching seed coats and otherwise damaging grain,” he says.

That trade-off can be incredibly difficult if harvest is delayed due to weather or unforeseen mechanical breakdowns. Since we can’t control the weather, we can do something about the machinery.

“Of course the engine should be well-serviced and maintained,” Hanna says. That means fuel, air and oil filters are checked and replaced if necessary, all fluids like oil and coolant are maintained according to the operator’s manual, and all belts are closely inspected and replaced. Paying close attention to all aspects of the machinery now can help avoid any problems in the field.

Most machine-related losses for corn and soybeans occur at the gathering head, so added attention to that area can pay significant dividends in minimizing crop losses. After all, you’ve grown the crop so why lose it now? “Cutterbar sections should be sharp and in-register with guards,” Hanna says. “Reel speed and position should be checked and appropriately adjusted for soybeans. Stripper bars on corn heads should be adjusted appropriately for ear size to avoid butt-shelling of ears and ear savers should be maintained on corn heads.”

In reasonable harvest conditions, operators should start at the lower end of suggested speed for rotor/cylinder rpm and wider concave settings. “Only thresh aggressively enough to limit losses to acceptable levels,” Hanna says. “Start at the high end of suggested fan speed in the cleaning shoe to fluidize separation, then slow fan speed as necessary to avoid blowing threshed grain out the rear of the combine.”

If the crop is standing well, operators should be able to limit machine field losses to less than 1 bushel per acre for corn (= 2 kernels per square foot) and soybeans (= 4 beans per square foot).

And get out of the combine to check for machine field losses often. This is especially true when moving from field to field, or hybrid to hybrid, during the rush of harvest. Even slight adjustments can mean the difference between putting grain in the tank or spreading it out on the field.

Also, here’s a video interview with Hanna on combine settings.

© 2013,