Reducing Soybean Harvest Losses in 2017

Average soybean harvest losses range from one to two bushels per acre under normal conditions. However, harvest losses can increase significantly when harvesting tall, lodged plants or short, drought-stressed plants. Due to the variable distribution of precipitation across the state this summer, some producers will harvest fields with significant lodging and others will harvest short plants with brittle pods. The recommendations provided in this article will help soybean producers reduce their losses under either scenario.

Harvest timing

Properly timing your harvest operations is critical to reducing harvest losses. Harvest operations can begin any time after the beans have initially dried to 14 to 15 percent moisture. Depending on weather conditions, this is usually about five to 10 days after 95 percent of the pods have reached their mature color. Try to harvest as much of your crop as possible before the moisture level falls below 12 percent to reduce splits and cracked seed coats. Shatter losses have been shown to increase significantly when seed moisture falls below 11 percent and when mature beans undergo multiple wetting and drying cycles. Shatter losses can be reduced by harvesting in the morning or the evening when relative humidity is higher.

Equipment maintenance

Before harvest operations begin, inspect and repair the cutting parts on the header. Make sure that all knife sections are sharp and tight and all guards are properly aligned. Check the hold-down clips to ensure that they hold the knife within 0.03125 inch (thickness of a business card) of the guards. Adjust the wear plates to the point that they lightly touch the back of the knife.

Equipment adjustment and operation when plants are tall and lodged

The main problem when harvesting lodged soybeans is the cutter bar will ride over uncut plants. The following recommendations will reduce this important source of harvest loss.

• Decrease your ground speed to 2.5 to 3 miles per hour.
• Increase the reel speed in relation to the ground speed incrementally to the point that the lodged plants are being cut and gathered into the combine without beating the beans out of the pods.
• Position the cutter bar as close to the ground as possible.
• Angle the pickup fingers on the reel back slightly to more aggressively pull the lodged plants to the cutter bar. Reduce the angle of the fingers if the plants are riding over the top of the reel.
• Run the reel axle 9 inches to 12 inches ahead of the cutter bar.
• Contact the manufacturer for specific recommendations if using an air-assisted reel.
• 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.
• Consider installing vine lifters on the cutter bar if the plants are severely lodged.
• If the plants are badly lodged in one direction, try adding vine lifters to the cutter bar and harvesting at a 30 to 45 degree angle to the direction of the lodging. If this doesn’t work, harvest all of the lodged plants in the direction opposite to way they are leaning.

Equipment adjustment and operation when plants are short and drought-stressed
The main problems that occur when harvesting short beans are gathering short plants into the combine after they have been cut and excessive shatter losses due to brittle pods. The following recommendations will help producers reduce these important sources of harvest loss.

• Position the cutter bar as close to the ground as possible.
• Consider purchasing an air-assisted reel as the air stream produced by this equipment effectively moves short plants and loose beans and pods to the auger or belt.
• Consider removing the rock 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 an angle in fields planted in 15 inch or 30 inch rows. This will help the short plants feed into the combine more unformly.
• Of all the combine adjustments, improper reel speed and reel position cause the most shatter losses so pay close attention to these in drought-stressed fields. Set the reel to run 10 to 20 percent faster than the travel speed and lower the reel so that it contacts the top a third of the plants. Reduce the reel speed and/or raise the reel if beans are being flailed out of the pods.
• Shatter losses can be reduced by harvesting in the morning or the evening when relative humidity is higher.

Source: Michigan State University