Reducing Soybean Harvest Losses

Soybean harvest losses result in lost income. Even under the most challenging conditions, soybean harvest losses can be reduced. Careful observation while harvesting will help identify and diagnose problems.

Recommendations for reducing harvest losses 


  • Decrease your ground speed to 2.5–3.0 mph.
  • Plant a range of soybean maturities that are adapted to the area to help prevent all fields from being ready to harvest at the same time.
  • Begin harvesting when the beans in the earliest maturing field first reach 15% to 16% moisture.
  • Complete harvest operations before the beans and pods undergo repeated wetting and drying cycles after they have reached 13% moisture.
  • Avoid harvesting beans that are under 11% moisture when excessive shatter losses are occurring.
  • Under hot and dry conditions, harvest in the morning and in the evening when the pods and beans have picked up some moisture and avoid the heat of the day if shatter losses are excessive.
  • Reduce the speed of the reel in relation to the ground speed if the reel is flailing beans out of the pods. Beans hitting the combine’s windshield is an obvious sign that the reel speed needs to be reduced.


  • Decrease your ground speed to 2.5–3.0 mph.
  • Position the cutter bar as close to the ground as possible.
  • Angle the pickup fingers on the reel back slightly to pull the lodged plants more aggressively to the cutter bar. Reduce the angle of the fingers if the plants are riding over the top of the reel.
  • Move the reel axle forward so that it is 9–12 inches ahead of the cutter bar.
  • Contact the manufacturer for specific recommendations if using an air-assisted reel in lodged soybeans. Moving the reel forward to pick up lodged plants decreases the performance of air-assisted reels. Pivot the drop tubes above the crop if this option is available or remove the entire air manifold and drop tube assembly.
  • Operate the reel as low as necessary to pick up lodged plants without causing them to ride over the top of the reel. Raise the reel if this happens.
  • Install crop lifters on the cutter bar in conditions of severe lodging.
  • When the plants are lodged in one direction, use crop lifters, and travel at a 20- to 25-degree angle to the direction of lodging. Alternatively, harvest the lodged plants traveling opposite to the direction they are leaning.
  • Increase the reel speed relative to the ground speed. It may be challenging to maintain the correct ground and reel speed combination in lodged beans with brittle pods. When ground speed is too fast relative to reel speed, the cutter bar will ride over some plants. When the reel speed is too fast relative to ground speed, the reel may shatter the pods. The reel should run 10% to 25% faster than ground speed under ideal conditions. However, in lodged beans, increase the reel speed incrementally up to a maximum of 50% faster than the ground speed. If the reel is causing pods to shatter, decrease the reel speed to the point when the shattering stops. If the cutter bar rides over lodged plants, decrease your ground speed.

Green stems

  • It is critical to continue harvesting soybeans having green stems even though it requires slower travel speeds and closer attention to cutter bar maintenance, reel speed and position, and threshing adjustments. Waiting for the stems to dry down will lead to large shatter losses.
  • If shatter losses are excessive, consider combining earlier in the morning or later into the evening when the pods have regained some moisture and are less brittle. However, this may increase plugging problems.
  • Reduce your ground speed to 2.5–3.0 mph if necessary. This will reduce shatter losses and plugging at the cutter bar by providing a crisp sideways cut.
  • Harvest at a 20- to 25-degree angle to the rows. This will improve cutter bar performance and provide more even feeding of the crop into the threshing cylinder or rotor. This may be the single most beneficial practice.
  • Draper headers should also reduce plugging problems when harvesting soybeans with green stems as they provide more uniform feeding into the threshing cylinder or rotor.
  • If the cutter bar is plugging, inspect and repair all identified problems. Check that the speed of the knife is correct and that drive mechanisms such as belts are not slipping. Make sure that the knife is in proper register with the guards. Rotate the knife through one complete cycle and make sure that the tips of the knife sections are centered on a guard at the beginning of a cycle and end up centered on a guard at the end of the cycle.
  • Maintain the reel speed at 10–25% faster than the ground speed. Fore and aft reel position is important to reducing slug feeding. Generally, positioning the reel as close to the auger as possible promotes even feeding into the combine.
  • Separating problems result from worn parts on the cylinder or rotor and improper cylinder or rotor clearance or speed settings. The separating equipment must be in good condition to handle soybeans with green or tough stems. Adjustments made to the cylinder or rotor clearance and speed is a balancing act between separating losses and seed damage and split beans. Make one adjustment at a time and inspect the clean grain tank to determine your progress toward minimizing separating losses and maximizing seed quality.

Short plants with low pods

  • Position the cutter bar as close to the ground as possible. Check and adjust the skid shoes on the bottom of the header to lower the cutter bar. You may need to increase the angle of the header to lower the front of the cutter bar (a 3-degree angle is a good starting point). This is a balancing act, as too much of an angle may increase the potential to pick up soil and stones leading to more broken guards and knife sections and cause cut plants and loose beans to build up on the cutter bar. Too flat of an angle may leave unharvested pods on the stubble due to a higher cutting height.
  • Purchase an air-assisted reel, wind system, or an air bar as the air stream produced by this equipment effectively moves short plants and loose beans and pods to the auger or belt. Follow the manufacturers recommendations for positioning the outlets on the drop tubes to maximize performance.
  • Remove the stone guard on the cutter bar if it is preventing short plants, loose beans, and pods from moving to the auger or belt and you do not have an air-assisted reel.
  • Harvest on a slight angle (15 to 20 degrees) in fields planted in 15- or 30-inch rows. This will usually help the short plants feed into the combine more uniformly.
  • The position of the reel will be critical to reducing gathering losses when harvesting short plants. With auger headers, positioning the reel as close to the auger as possible provides the most uniform feeding under most conditions. However, you may need to experiment with fore and aft reel position with very short plants. Lowering the reel is recommended when plants are short to prevent the plants and beans from building up on the cutter bar. The tips of the reel fingers should be about 1.6 cm above the top of the guards or the header floor.
  • Set the speed of the reel about 10–25% faster than the ground speed and adjust as necessary to improve feeding.
  • Set the speed of the belts on draper headers fast enough to assure plant material isn’t building up on the cutter bar.
  • Experiment with your ground speed to find the sweet spot where the cut plants are feeding well into the feeder house and the stubble is cut cleanly and uniformly.
  • Reduce shatter losses by harvesting in the morning or evening when relative humidity is higher.

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