Due to the warm and dry fall weather conditions, many Michigan producers harvested overly dry soybeans (8 to 10% moisture) and are storing them on the farm. These producers will lose income at delivery due to lost water weight as the market standard for soybeans is 13%. The following table shows how the value of a bushel of soybeans decreases as the moisture content falls below 13%.
|Table 1. Value of a bushel of soybeans harvested and delivered at various moisture levels.|
|Moisture (%)||Weight per bushel (lbs.)||*Value ($/bu)|
* The USDA 2022-2023 estimated market price of $14 per bushel was used when calculating value per bushel.
While it is illegal to add water to any grain crop, it is legal to recondition overly dry soybeans using the moisture contained in ambient air. Producers storing overly dry soybeans on their farms and having the proper equipment should consider trying this this fall or spring.
Ken Hellevang, agricultural engineer at North Dakota State University (NDSU), is a well-recognized expert on reconditioning soybeans and most of the information presented in this article comes from Hellevang. Anyone considering reconditioning soybeans this fall or spring should read the following articles:
For more information about reconditioning, drying, handling and storing soybeans, see NDSU’s Grain Drying and Storage website.
The concept of reconditioning grain is simple. Moist ambient air is pushed or pulled into the grain mass through aeration fans creating a wetting front that moves through the grain. Reconditioning time is dependent on airflow and weather conditions and can take at least a month. The relative humidity of the air is critical to success.
If the air is too dry, further grain moisture losses will occur. If the air is too moist, the moisture content of the beans can exceed safe levels for safe storage. The optimum relative humidity is 70%. Once air temperatures fall to or below 40 degrees Fahrenheit, there is not enough moisture in the air to recondition the grain.
Reconditioning can occur this fall if air temperatures are above 40 F or can begin in the spring when air temperatures rise.
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Hellevang offers some recommendations for controlling the humidity of the air entering the bin. One method is to add two humidistats to control the fan—one to turn the fan on when humidity is above 60% and another to shut the fan off when the humidity is above 90%. Another option is to install a microprocessor-based controller that monitors temperature and humidity. The final and least technical option is to run the fan only at night and foggy mornings. This option results in reconditioning but provides no control over the level of humidity entering the grain mass.
Because reconditioning involves moving moist air through the grain mass, it is best performed in drying bins having perforated floors and fans rated at delivering at least 0.75 cubic feet per minute per bushel.
Reconditioning soybeans is risky. The beans may exceed the moisture level for safe storage and the additional moisture may cause the beans to swell and damage the bin. Both conditions can be reduced by reversing the fan so that the air is pulled through the top of the grain mass and periodically removing a layer of beans from the top after they have been reconditioned.
Periodically removing some grain is always recommended to protect the bin regardless of whether the fans are applying positive or negative pressure. Producers that have bins equipped with vertical stirring augers can use this equipment to mix wet beans with drier beans periodically. Remember that dry soybeans are fragile and this method will most likely increase the level of split beans in the bin.
Reconditioning can be an effective way to increase the value of overly dry soybeans, however careful management is required.
This article was produced by a partnership between Michigan State University Extension and the Michigan Soybean Committee.