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CLEANING OUT your planter between crops used to be as easy as dumping the old seed out of each hopper. Not anymore.

With the rising demand for food-grade and identity-preserved crops, more Midwest corn and soybean growers are planting crops outside the commodity realm to receive a premium for their grain. Buyers do not want genetically modified (GM) crops mixed with their grain and impose strict quality standards that growers must meet for their grain to be accepted.

A high-risk time for contamination occurs at planting because of the multiplier effect that happens with seed. “If you plant one bad seed of the wrong variety, it multiplies several hundredfold during the crop season,” says Dr. Mark Hanna, extension agricultural engineer with Iowa State University. “In both corn and soybeans, just a couple of seeds per 1,000 ft. of row can contaminate a load of grain.”

Quality standards

Contamination prevention, a huge topic in the livestock industry, has been largely overlooked by the crop industry, according to Ron McKiernan-Struve, training manager for Kinze Manufacturing. “You can't walk in or out of a hog confinement building without passing through a shower and changing clothes,” he says. “You won't find the same level of care in the crop industry.”

The reason, he says, is that Midwest corn and soybean producers to date have not been penalized for having GM grain mixed in their grain shipments. That's changing as growers plant crops beyond the commodity realm and are now subject to quality standards livestock producers have faced for years.

If all you grow is commodity corn or soybeans, a few seeds from another field won't affect the value of your grain in most cases. However, if you grow a crop for any other use, quality standards will dictate how much, if any, foreign material can be in your sample. Standards can range from 0 to 5% or higher, depending on the buyer.

According to Dirk Maier, agricultural engineer with Purdue University, a zero-tolerance standard applies to any GM trait that has not received approval from the USDA Animal and Plant Health Inspection Service for commercial release in the U.S. and the markets of our major buyers. “An example of that would be StarLink from a few years ago and more recently the Syngenta Bt-10 trait that was found in the export channel to Japan,” Maier explains.

Zero tolerance also applies to GM traits that have not yet been approved in Europe but have been approved in the U.S. and in the markets of our major buyers such as Japan. “This is known as the MarketChoices Corn program,” Maier says. “When it comes to cleanout and segregation of any other traits — that is, GM versus non-GM grain or quality attributes such as white versus yellow corn — the marketplace has established reasonable tolerance levels.”

For more information about grain quality standards, visit

How to get to zero

Iowa State's Hanna has devised extensive planter cleanout procedures to help growers meet these grain quality standards. You can download a general bulletin called “Planter Cleanout Tips When Changing Seed Varieties” (PM 1847) for no charge at (click on the “extension outreach” tab followed by the “ag machinery” tab). The bulletin covers several common planter styles including finger-type seed metering, single seed metering, or central metering systems.

Videos and fact sheets also are available, covering individual makes and models of equipment. They can be purchased online for a nominal fee at

Cleanout procedures will vary by style of planter (see sidebar). However, in general, there are three areas to look at:

Seed hopper. The first area to clean is individual seed hoppers. “Dumping each seed hopper into seed bag or bulk container is the regular cleanout that most folks do,” Hanna says. However, he says, a total cleanout will require more than that.

“Usually there is a correct corner of the seed hopper you need to pour out of in order to empty the seed metering mechanism properly,” Hanna says. “If you go out of just a random corner, you are likely to get more seeds caught.” Growers should check their operator's manual to learn which corner to use.

Seed-metering system. Checking inside the seed-metering system for seed is a process that can take anywhere from 2 to 4 min./seed-metering unit, depending on the geometry of the planter. Some disassembly is required. Specifically, the meter mechanism, located on the lower part of the seed hopper, must be opened to allow you to look inside the meter for seeds.

“For example, air systems have a seed plate you will need to remove,” Hanna says. “Once you remove the plate, look inside the meter and around gaskets or seals. And look for seeds caught behind the seal or cutoff brush.”

Finger-type metering systems have a cover over each meter, attached by three wing nuts, that needs to be removed to expose the fingers and cutoff brush. Air-type planters often have a swing-away cover that you can open to inspect inside the meter.

Planter frame. The third area to check is the planter frame itself. Seed can collect on the lower parts of the row unit, including the depth-gauging wheels, the double disc seed opener, or the closing wheels. “A lot of times there will be moist soil somewhere on the planter that seed will stick to as you dump the hoppers,” Hanna explains. “Or soil can collect at the bottom of the seed tube and cause seeds to back up. So after you've opened up and inspected the seed meter, a finishing step is to check the closing system behind the planter and lower parts.”

Hanna says planter cleanout may take on average 30 to 60 min., depending on the number of row units. If you are selling to an end user or have a contract with a local elevator, you should document the procedures you used, complete with signatures and dates.

Planter makers offer help

Manufacturers have begun to incorporate cleaning protocols in their planter clinics and customer training programs. John Deere, for instance, offers a one-day training program in specified geographic locations for buyers of its new CCS (Central Commodity System) planters. Cleanout procedures are thoroughly covered in the program.

“In 2002, we introduced the Central Commodity System and Pro-Series row unit to the market,” says Brian Childs, senior sales and service representative, John Deere Seeding Group. “The Central Commodity System provides a central-fill location and more time between fills. The Pro-Series row unit can be completely emptied without removing the meter and hopper from the row unit. The operator can simply walk up behind the row unit, remove the vacuum cover and seed disc, and the seed will empty into the catch pan provided with each planter.”

Kinze Manufacturing's McKiernan-Struve echoes the same claim about his company's central-fill planter. “Our newly introduced EdgeVac uses a vacuum fan or air system to singulate the seed,” he says. “No tools are required to disassemble the meter. Simply remove vacuum cover and seed disc, and all seed can be easily seen and readily dumped out.”

In comparison, seed that is singulated by the “finger” meter goes onto a separate belt and is hidden by conveyer housing. The meter must be rotated with a special tool in order for the seed to be ejected.

White engineers had ease of cleanout in mind when designing the hopper and meter for White planters, owned by AGCO, according to Jeff Daniel, sales engineer for White planters. “The need for having a complete cleanout is extremely important,” Daniel says. “Even when planting seeds like soybeans, whether the seed is genetically modified or non-genetically modified can affect the acceptance and value of the crop.”

Case IH's new 1200 series bulk-fill system also was designed with seed cleanout in mind. Both the bulk-fill system and Advanced Seed Meters are equipped with seed cleanout doors. By following the recommended procedures, customers can achieve the degree of cleanout desired.

Midwest growers who adhere to proper planter cleanout procedures will guard against contamination of their grain and remain competitive by ensuring a quality product.

CASE IH 1200

Case IH 1200 advanced seed meter

  1. While the meter is still attached to the row unit, place a small container under the seed release door, open the door to empty the meter and mini-hopper (bulk fill) or on-row hopper contents.

  2. Disconnect the vacuum hose and remove the seed meter. Disconnect the meter cover latches and remove the cover. Remove the seed disc retention clip and pull the seed disc off the drive mechanism.

  3. Remove seeds from the inside of the meter housing and replace meter components.

  4. Replace the seed meter assembly back onto the row unit.

Case IH 1200 bulk-fill system

  1. Close the bulk-fill hopper gate.

  2. Open the seed cleanout hatch and catch seeds in a container. Container size will depend on the amount of seed left in each hopper.

  3. Once the container is in place and the cleanout latch is open, move the hopper gate to the open position to remove the remaining seed from each hopper. Adjust the hopper gate to manage seed flow.

  4. Once finished, close the cleanout latch and open the seed hopper gate.

  5. Repeat the process for the opposite side hopper.


Kinze mechanical “finger pickup” seed meter

  1. Dump seed from each hopper by tipping the hopper toward the corner of the hopper marked “empty here.”

  2. Slip the crank tool on the meter driveshaft while the meter is on the hopper.

  3. Using the crank tool, turn the meter one to two full revolutions to eject seed from the meter.

  4. Shake the meter and listen for any remaining seeds.

  5. Using the crank tool, turn the meter again until all seeds are ejected.

Brush-type seed meter

  1. Dump seed from each hopper by tipping the hopper toward the corner of the hopper marked “empty here.”

  2. Pull the seed disc off the meter.

  3. Visually inspect the meter and mechanism for seed and debris.

  4. Dump remaining seeds.

  5. Reassemble when meter looks clean.

EdgeVac meter

  1. Dump seed from the hopper by tipping the hopper toward the corner of the hopper marked “empty here.”

  2. Remove vacuum cover and seed disc on the meter.

  3. Visually inspect the meter and mechanism for seed and debris.

  4. Blow out remaining seed with compressed or vacuum air.

  5. Reassemble when the meter looks clean.

Additional steps

  • Visually inspect axle and planter frame for spilled seed and debris.

  • Brush or clean off with hand or compressed air.

If using bulk seed delivery system:

  1. Put open seed tote or tub under the planter cleanout door on the hopper.

  2. Run the auger until seed in the main hopper is purged.

  3. Use compressed air and a long nozzle to dislodge seed caught on ledges.

  4. Run the auger again to purge remaining seed.


John Deere 1770NT CCS or 1790 planter with Pro-Series row units

  1. With the planter in the raised and folded position, empty the cleanout doors on the bottom of the Central Commodity System (CCS) tanks while using a bucket or container to catch seed from the tank. In order to remove 100% of the seed from the CCS tank it may be necessary to use an 8-in.-wide stiff bristled broom with a 4.5-ft. handle.

  2. Flip the “Purge Hoses” switch located on the cradle in front of the CCS tanks and adjust the CCS fan control knob until 20 in. of tank pressure is achieved to guarantee good tank cleanout. This will purge the seed delivery hoses and move any remaining seed to the row-unit hopper.

  3. Install the seed meter catch pan on the row unit, open the vacuum meter dome and remove the seed disc. All of the seed in the row-unit hopper should now be located in the seed meter catch pan. Repeat for each row.

  4. Return to the center of the machine and flip the “Purge Hoses/Plant” switch to the “Plant” position and adjust the CCS fan control knob to the recommended amount of tank pressure.

John Deere Max Emerge row unit (which can use a vacuum meter, finger pickup meter, or radial bean meter)

  1. Vacuum meter. Remove hoppers from each row unit and empty each hopper and vacuum seed meter by inverting the hopper. Rotate the hopper so seed is slowly poured from the left-hand corner. When the hopper is empty, some seed will remain in the meter housing. To empty this seed, rotate the hopper back to the operating position. Invert the hopper again and pour from the left-hand corner to empty seed from the meter housing.

  2. Finger pickup. Remove and invert each hopper. Rotate the hopper so seed is slowly poured from the right-hand corner. When the hopper is empty, some seed will remain in the meter housing. To empty this seed, rotate the hopper back to the operating position. Invert the hopper again and pour from the right-hand corner to empty seed from the meter housing and rotate the meter flex drive to remove seeds from fingers and seed belt.

  3. Radial bean meter. Remove and invert each hopper. Return the hopper to the upright position and rotate the meter flex drive to empty remaining seed from metering cells.


White planters are equipped with a seed drain funnel to aid in removing any seed in the hopper and meter. To clean out the hopper and meter using the seed drain funnel:

  1. Position the funnel under the meter along with a receptacle and remove the seed disc.

  2. The seed will flow out of the hopper into the sump area of the meter and then down the funnel into a receptacle.

  3. The design of the roof of the meter is such that the seed flows down the meter throat into the sump area.

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