Late harvest resources available from U of M Extension service
Soybean moisture levels of 16 to 20 percent or more at harvest have been reported throughout the state as this challenging harvest season continues, according to Lizabeth Stahl, crops educator with University of Minnesota Extension. At these moisture levels, mold becomes a storage concern. Much of the state's corn crop is also wet and unharvested, meaning that drying and storing is an important topic for corn as well as for soybeans.
To provide detailed information for growers, University of Minnesota Extension has developed a Web site full of resources devoted to dealing with this unusually cold and wet harvest season. Find these resources at www.extension.umn.edu/lateharvest.
Detailed information about the drying of soybeans and corn can be found at this site as well as information about potential corn grain quality issues this fall and advice of minimizing the effects of soil compaction. Here are a few key points for corn and soybean growers:
Bill Wilcke, agricultural engineer with University of Minnesota Extension, reports that as a guideline, soybeans in storage tend to act about the same as corn that is 2 percentage points greater in moisture content. For example, soybeans at 16 percent moisture could be expected to act like corn at 18 percent moisture. Aeration is always recommended with all storage facilities. If storage temperatures are below about 60 degrees, soybeans at 13 percent moisture can usually be kept for about 6 months without having mold problems.
Artificial drying of soybeans will be needed if soybeans are harvested and stored at a moisture content greater than 13 percent. According to Ken Hellevang at NDSU Extension, soybeans can be dried in a high-temperature dryer, but the plenum temperature needs to be limited to minimize damage to the beans. Refer to the manufacturer's recommendations for maximum drying temperature. Typically the maximum drying temperature for nonfood soybeans is about 130 degrees. Even at that temperature, some skins and beans will be cracked. Food soybeans and seed beans must not have damage to the seed coat, so natural-air or low-temperature drying is the preferred drying method, Hellevang said.
Wilcke said corn will need to be dried in a high-heat dryer if the corn moisture is higher than about 22 percent. Most years, corn does well with natural air drying, and some producers may still be able to dry corn this year by blowing some slightly heated air up through their grain bins (air heated to about 10 degrees higher than outdoor air temperature). If the moisture is higher than 22 percent, there may be little choice but to use a high-heat dryer. Dryer designs vary, so see instructions for temperature recommendations. Start with the lower end of the temperature recommendation if corn quality is a concern and turn it up if corn drying capacity is not sufficient. Using energy for heated-air drying is expected add to overall costs for producers this year.