Moisture content of about 13% at harvest is optimal for mitigating mechanical damage
Harvest timing can have a huge impact on soybean shatter losses and storability. Field losses, splits and cracked seed coats increase as moisture content decreases.
A moisture content of about 13% at harvest is optimal for mitigating mechanical damage.
Shatter losses increase significantly when seed moisture falls below 11% or when mature beans undergo multiple wetting and drying cycles. Also, molds develop more rapidly in soybeans with seed coat cracks, so the amount of mechanical damage during harvest affects the beans’ deterioration rate.
Harvesting during high humidity, such as early morning, late evening or in damp conditions, may reduce shatter loss and mechanical damage if the soybeans are below 11% moisture content. Moisture content can increase several points with an overnight dew or decrease several points during a day with low humidity and windy conditions. Avoid harvesting when beans are driest, such as afternoons.
The market moisture for soybeans is 13%, which is fine for storing soybeans during cool conditions. If your soybeans will be stored through winter and into the warmer weather of spring and summer, store at 11% moisture to limit mold growth and deterioration. The storage life roughly doubles for each percentage point of reduction in moisture content.
Storage Temperature
Controlling soybean temperature during storage is critical. Free fatty acid percentages, a negative characteristic, tend to increase with storage moisture, temperature and time.
Store soybeans during the winter near 30 F in northern states and 40 F or lower in southern states.
At 12% moisture, free fatty acid percentages increase slowly with storage time if the beans are kept cool. In one study, the average free fatty acid content of 12% moisture beans stored at 50 F stayed below 0.75% but exceeded this level after only four months when stored at 70 F.
Cool soybeans as they go through the fall and winter to maintain quality. Aerate to keep the soybeans within 10 to 15 degrees of the average outdoor temperature during the fall.
Store soybeans during the winter near 30 F in northern states and 40 F or lower in southern states.
During the spring and summer, aerate stored soybeans to keep the temperature as cool as possible - preferably 40 to 60 F. These temperatures enhance soybeans’ storage life, and reduce mold and insect activity.
Soybeans at 11% moisture have similar storage characteristics as wheat or corn at 13.5% to 14% moisture. Use an allowable storage time chart for cereal grains to estimate allowable storage times for soybeans.
Storage Recommendations
For more information, visit NDSU grain drying and storage.
Information provided by North Dakota State University.