Don’t forget to pay attention to potential shattering as you get ready to harvest. Harvestability of soybeans means the combination of when the vegetative material can flow through the rotor and keeping as many pods and collecting as many bean seeds as possible.
Shattering can cause yield losses that reach 5 to 10 percent. To reduce shatter losses, harvest as soon as soybeans reach 14-percent moisture content and dry to combine in that 12% to 14% range. If storing soybeans in a bin on-farm, with capacity to blow air, start at 16-percent moisture and aerate to dry them down to 13 percent.
If your soybeans have over dried, wait until after a rain or harvest early in the morning when pods are damp from dew. Because shatter losses are higher after several cycles of pods wetting and drying, it may be best to wait for beans to have more moisture.
When soybeans were priced around $5 to $6 a bushel, losing a few bushels from harvest loss was not a large financial burden. Today, however, losing one or two bushels per acre could be a $10 to $25 loss per acre. A good goal is to keep harvest loss under one bushel per acre (2 to 4 seeds per square foot). The key to minimize loss is to continually adjust the combine for your crop conditions.
Of course today’s draper headers are known to be more efficient at harvest and can hug closer to the soil surface capturing more pods and reducing shatter loss under an auger. Material flows more steadily on the platform and feeds into the combine more uniformly, eliminating slugging that can clog a combine throat.
Watch for green stems if combining soybeans before the first frost. Harvesting soybeans with green stems is slower and takes more fuel. Growers need to adjust their combines to handle green stems and then readjust as the stems and beans dry down during the day. A hard frost will kill those green stems, eliminating this harvesting headache. But frost right now wouldn’t be good because there are still a lot of acres of soybeans that need time to reach maturity.
Adjust the combine platform to harvest as many pods as possible. Cut as low as possible without picking up dirt and rocks. A 3.5-inch stubble contains 5 percent of the crop while a 6.5-inch stubble contains 12 percent of the crop. Some farmers have taken to rolling their soybean fields right after planting to level the ground and press stones and rocks back into the soil so they can run their platforms even lower.
Your harvest loss can be kept at a minimum by running the cutter bar as close to the ground as possible and not driving too fast. Use a reel speed about 10 to 25 percent faster than ground speed, and up to 50 percent faster if the crop is lodged, and keep the reel axle 6 to 12 inches ahead of the cutter bar and as low as possible. Finally, complete the harvest as quickly as possible after beans reach 14% or lower moisture content.
Agronomist Dr. Daniel Davidson posts blogs on agronomy-related topics. Feel free to contact him at firstname.lastname@example.org