Farmers rarely store many bushels of soybeans. If they have on-farm storage they want to use it for corn. Besides, there has rarely been much carry in the soybean market to make it worth storing beans, considering that you have to handle the bushels twice. But then some growers do store some beans on-farm and hold them for later delivery for cash flow purposes.
As with corn or wheat, spoilage will occur quickly if storage moisture and temperature are too high. The high oil content of soybeans (18 to 20% oil) makes them more susceptible to spoilage than corn; therefore, soybeans need to be about two points dryer than corn for proper storage.
For winter storage store beans at 13% moisture or less. Soybeans with less than 15% moisture can be air-dried with bin fans. Soybean seed stored over the next planting season should be held at 12% moisture or less. Soybeans stored as seed should be held at 10% moisture or less. In a normal year, natural air will dry soybeans to 13% moisture. But in cool, wet falls, supplemental heat may be required.
When using fans, consider that soybeans have 25% less airflow resistance than shelled corn, so fans sized for corn drying will produce greater airflow through soybeans. Greater airflow means faster drying and cooling. The recommendation for drying soybeans is to reduce heat and limit air drying temperature to 130 to 140⁰ F for commercial beans. Retention time in the dryer should be less than 30 minutes.
The general course of action is to dry the grain down with air quickly and cool the grain down as air temperatures drop over the fall and into winter. All farmers have a moisture meter and can use this to test moisture and temperature of soybeans going into storage. However, once beans are moved into storage it is more difficult to track these metrics. Growers can also use a 6- or 10-foot probe to collect samples from various depths at bin center and outwards and then monitor moisture and temperature with a handheld meter. Sensors can also be hung on cable in bins, allowing growers to track moisture and temperature and look for hot spots.
By checking stored grain weekly growers can identify problems before they become unmanageable. Even grain in good condition in the fall can develop problems over the winter. If heating, mold or foul odors occur, unload the bin and sell, or dry the beans at high temperatures. It is a common practice to pull out a load from the core of the bin where grain tends to stay moist and overheat.
Other soybean storage tips:
- Level off bins immediately after harvest.
- Avoid using worn augers and mechanical spreaders that will damage the seed while filling.
- Aerate bin as soon as it is filled to remove the heat, regardless of the moisture.
- Aerate soybeans to maintain grain temperature at 35 to 40⁰ F in winter and 40 to 60⁰ F in summer.
- Check bins every few of weeks throughout the season for surface crusting, moisture and temperature migration and aerate as needed.
Get Involved: Let us know how you maintain soybeans in storage.
Agronomist Dr. Daniel Davidson posts blogs on agronomy-related topics. Feel free to contact him at email@example.com.