Adjust combine setting for harvest after drought

In a year when corn farmers will undoubtedly be facing lighter test weights and smaller cobs, it is important to fine-tune machinery to get the highest yield out of fields this harvest season.

Mark Wieland, a manager for Sydenstrickers of Tipton, says the 2012 growing season is leaving many farmers with less-than-ideal harvest conditions. “They are seeing smaller cobs, weaker stalks and overall lower yields,” he says. “For the younger generation of farmers, this is not the conditions they are used to.”

Key Points

• Combine setting should be changed for harvest if it’s dry.

• Smaller stalks require narrower spacing in deck plates.

• Reduce ground speed to get the most yield from fields.

Wieland recommends that before opening a field, farmers first look at the field, and then their corn head. “Adjusting the deck plates on corn heads will be the most important thing guys can do this year.”

Snug set

Deck plates should be set according to stalk size. Smaller stalks require a closer plate setting. Wieland says that hydraulic deck plates may even need to be adjusted manually to closer than the factory setting. A gap of 1.25 inches in normal years will likely need to be narrowed closer to 1 inch for smaller ears.

“Even on the end setting,” he says, “it may not be close enough. You may need to move them closer.” Farmers will need these adjustments to get the clearance they need in the fields, he adds.

Grain farmers may also need to make adjustments in the field, depending on the conditions. “It may take more time this year to get the crop out of the field.”

To help prevent crop loss, take a closer look at the gathering chains. Flights on gathering chains should be set together to allow the head to grab the stalk more aggressively and pull it through the combine head. This will also minimize ear loss.

Smaller kernel size may require reduced sieve openings in the cleaning shoe. By making this small adjustment, it will create a cleaner sample.

Install inserts

With a prediction of smaller, softer cobs, getting kernels off will be cumbersome. One way to help the process, Wieland says, is to install concave inserts.

Matching the concave spacing with the cob size is important to ensure less splitting or breaking of the cob. “Concaves may have to be set closer than normal to remove kernels, especially if the cob is spongy or rubbery,” he adds.

Installing concave inserts on rotor machines may also be needed to remove grain. Although it is not typically recommended for corn, Wieland says the practice may help this year.

Speed sensitive

Several equipment speed adjustments can help put more grain in the hopper.

One key area is to match corn head speed with ground speed. Wieland warns that just because it may not look like a larger harvest, farmers should slow down to get as much grain out of the field as possible.

“We want to glean as may ears as we can,” he says. “The grain still has to separate from the residue.”

Air drag can be greater on smaller ears, so farmers may want to consider slowing down fan speed.

However, farmers can increase rotor or cylinder speed. With a typical harvest, a slower rotor speed is preferred. Wieland says that increasing rotor or cylinder speed allows more grain to be removed from the cob.

Ultimately, slowing down this harvest season may yield the best results. “Be patient,” Wieland says. “Just because a crop is smaller and yields less doesn’t mean you have to fly through it. There is still some yield in the fields, and we need to get as much as we can.”


Deciding factor: Mark Wieland points out that deck plate adjustment should be the No. 1 priority at harvest, should dry weather persist in the Midwest.

This article published in the September, 2012 edition of MISSOURI RURALIST.

All rights reserved. Copyright Farm Progress Cos. 2012.