Soybean harvest: When the time is right

September 15, 2023 1:37 PM
Blog Post

Every year soybean harvest has some type of challenge. Soybean is one crop where it is difficult to get all the conditions perfect. The use of draper style headers with soybean harvests allows harvest to begin earlier and handle green stems, green pods, and variable moisture.

Below are several items to consider this harvest season:

  • Soybean moisture: The optimum yield occurs at 13%. Most grain elevators dock for moisture content above 13% moisture, so we want to avoid harvesting soybean above this moisture level due to storage concerns. However, we do want to be in that 12 to 13%, which is the “sweet spot” This is not always possible; however, if we harvest at lower moistures, we are losing yield. If we harvest at 8 % moisture, we are losing about 5.4% of our yield; at 9% moisture we are losing 4.4% of our yield; at 10% moisture, 3.3 % of our yield; at 11% moisture, 2.25% of our yield, and at 12% moisture, 1.1 % yield loses occurs.
  • Harvest yield loss: For every four to five soybeans per square foot, this is equivalent to about one bushel per acre loss. Header loss and shatter are more problematic in dry soybean conditions. Be sure to stop and make adjustments as needed to help minimize this loss.
  • Green stems: Green stems often only limit the header capacity, and do not necessarily impact yield. Harvesting soybeans with green stems is limited by the equipment available and combine capacity. Additionally, it usually results in more fuel consumption and potential for plugging. If harvesting soybeans with green stems, ground speed may need to be reduced.
  • Green pods and beans: Green pods and beans are a grain quality issue. They also can impact yield, but at this point we can not influence yield with management now. Additionally, green pods and beans can cause heating in the combine tank or trailer if left for period of time. We want to avoid storing a large percent of green beans in bins. If harvesting green beans keep those loads separate and monitor closely this fall after harvest.

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Aaron Saeugling Field Agronomist in SW Iowa

Aaron Saeugling is a field agronomist in southwest Iowa for Iowa State University Extension and Outreach.