Extension offers advice on handling, drying of soybeans
WILLMAR -- University of Minnesota Extension crop experts are encouraging soybean growers to harvest the crop as early as possible to prevent yield losses due to splitting, lodging or poor threshing of the plant. However, if soybeans are harvested at greater than 13 percent moisture, artificial drying is necessary.
Growers should manage their options for storing higher-moisture soybeans according to the following recommendations, says Extension agronomist Seth Naeve:
- Soybeans with greater than 13 percent moisture are likely to mold under warm conditions. However, if the storage temperature is kept below about 60 degrees, soybeans can usually be stored for at least six months -- at 13 percent moisture -- without mold problems.
- For storage in temperatures higher than 60 degrees or for periods of time lasting longer than six months, the recommended moisture content is 11 percent. Soybeans harvested at 11 to 13 percent moisture can be placed directly into ordinary storage bins equipped with simple aeration systems -- perforated ducts or pads and relatively small fans.
Farmers are advised to follow these natural-air drying guidelines: Using unheated air to dry soybeans usually works well, but it's a slow process lasting two to six weeks, depending on initial moisture, airflow and weather.
In southern Minnesota, use airflow of 1 cubic foot of air per minute, per bushel (cfm/bu) to dry beans with 17 to 18 percent moisture, 0.75 cfm/bu for beans with 15 to 17 percent moisture, and 0.5 cfm/bu for beans with 13 to 15 percent moisture.
If cool, damp weather prevents soybeans from drying to 13 percent moisture, consider adding a small amount of heat to the natural-air dryers. However, do not heat the air more than 3 to 5 degrees, or you will overdry the beans and possibly cause an increase in splitting.
Research shows that exposing soybeans to relative humidity values of less than 40 percent can cause excessive splitting.
Get more information on soybean drying, handling and storage at http://www.soybeans.umn.edu/crop/harvest.
Minimize yield losses
Although most soybeans have reached maturity, harvest losses that don't make it inside the combine account for roughly 80 percent of harvest loss, according to Extension crops educator Dave Nicolai. To minimize this loss, Nicolai says it's essential to remember that ground speed, combine adjustments, and the location and speed of the pickup reel are important factors.
"Check losses periodically in the field and adjust your combine for the crop conditions," Nicolai said.
Estimating soybean harvest loss: Estimate loss by checking an area of 10 square feet, Extension experts suggest. Approximately 40 soybeans lost in this area will add up to one bushel per acre. Make loss determinations at several locations and calculate an average.