Marion’s Top Tips for Harvesting Narrow Row Corn

1. It’s best to harvest 15-inch rows with a 15-inch row corn head, especially in research plots. If a 15-inch corn head is not available, you can use a 30-inch row head, which pulls two 15-inch rows together, but there is greater potential for ear loss. Avoid this potential ear loss by reducing ground speed. Harvesting early, and using BT hybrids.

2. Farmers claim they can harvest down corn easier in 15- and 20-inch rows than in wide rows.

3. Finding the rows at harvest can be challenging in severely windblown 15- and 20-inch corn. White-colored corn head divider snouts, a guidance system, and auto header height are all helpful when harvesting in these conditions.

4. Farmers say 15- and 20-inch corn heads can pick in any direction.

5. Shorter divider snouts are available for use on contours.

6. Farmers claim they can harvest faster in 15- and 20-inch rows.

7. The yield advantage for narrower rows varies by year.

8. Farmers have stated corn heads with a single-gathering-chain design perform as well, if not better, than corn heads with dual gathering chains.

9. Since the machinery costs to switch to narrow rows are significant, the yield advantage must be great enough to cover these costs. At my farm, I need a yield gain of approx. 5 bushels per acre to remain profitable.

10. The profitability of 15- and 20-inch rows is determined by multiple factors. these factors include:  the number of acres farmed, the number of planters and corn heads needed for different crops and row spacings, the cost to modify equipment, the yield advantage, and the savings realized through improved weed and erosion control. At my farm, all of these factors combined provide a savings of approx. $84/ac per year vs. wider rows.

Helpful Documents



12-, 15-, 20-, 22-, 30-inch row heads

Combine settings & Refinements
For Corn Harvest

Click any item to watch the video of Marion talking through each combine tip

Sieve Settings for Corn

Our most watched video on YouTube. Harvest with the bottom sieve wide open! Watch the discussion here.

Corn Head Angle

The right angle of attack improves wear life and effectiveness of the stalk rolls. Park the combine on a level surface and lower the header until the lowest point of the row unit is approx. 2-inches above the ground. Place a protractor on the plates to measure the angle. Try to achieve 23-25 degrees in standing corn. 

Gathering Chain Speed

Begin calibration with initial gathering chain speed of 55 RPM.  If you are seeing butt shelling, slow down the corn head until it starts to bulldoze cornstalks then speed back up until bulldozing stops.

Cross Auger Adjustment

Fine tune your cross auger to prevent ear slicing and cracked grain. Adjust vertically to have 1 3/4-inches of clearance between flighting and the tray. 

Stripper Plate Gap

Pull a stalk from the field to test your stripper plate gap. Ensure the stripper plates are wider than the the third cornstalk node from the brace root. Watch our video for full settings. 

Feeder House Chain

During your pre-harvest maintenance routine, adjust the feeder chain to maximum length and as close as possible to the cross auger. Run at maximum speed to reduce the potential of ears piling up during the handoff from the corn head to the feeder house. 

Rotor Speed

Increase your combine's rotor speed until you can see the first cracked kernel in the grain tank then reduce speed by 10RPM.

Fan Speed
in Corn

Increase fan speed until the red chaff and pieces of broken leaves are no longer showing up in the grain tank.

Case IH
Transport Vanes

Adjust transport vanes to the slow position (bottom of the vanes to the back of the combine). This will reduce kernel loss from the rotor area.