How to Quickly Clean Your Combine of Weed Seeds

( Darrell Smith )

In the hustle and bustle of harvest, it might be crazy to think about stopping in between fields to clean your combine. However, if you don’t, you might be setting yourself up for bigger challenges next year, and in years to come.

“With something like waterhemp, one million seeds in a combine isn’t unlikely,” says Bob Hartzler, Iowa State University Extension weed scientist. “A study showed if you want to completely clean out a combine to eliminate weed seeds it would probably take two days, but if you finish a field and just run the combine to blow it out, that’ll probably eliminate three-quarters of the seeds.”

Bolstering clean out time to 30 minutes would help you achieve 95% weed seed-free status, he adds.

“[Combines] can have as much as 150 pounds of biomaterial, including chaff, grain and the seed of weeds such as Palmer amaranth,” said Tom Peters, North Dakota State University (NDSU) Extension weed expert in a recent press release. “This material may remain in tight spaces, or in obvious places, such as the gather head and grain tank.”

Here are a few tips from the North Central Agricultural and Natural Resources Academy for cleaning out the combine:

  • Run the unload auger while empty for at least one minute.
  • Open and clean the grain and tailings elevator doors, rock tramp and unloading auger sump.
  • Start the combine and separator. Adjust the cleaning shoe fan to full speed for max airflow or open and close cleaning shoe sieves electronically. Adjust the rotor to full speed for max air suction or open and close the concaves. Do this for at least two minutes.
  • Remove any material left in the rock trap.
  • Use an air compressor or leaf blower to remove material from the exterior of the combine, focus on the head, feeder house and axel and straw spreader at the rear.
  • Close the doors to the rock trap and clean the grain elevator and unloading auger sump.

You might not be able to remove all debris, but cleaning between fields will greatly reduce the movement of weed seed, says Angie Johnson, NDSU Extension agriculture and natural resources agent in Steele County.