Soybean moisture levels of 16-20% or more at harvest have been reported throughout the state as this challenging harvest season continues. If storage temperatures are below about 60° F, soybeans at 13% moisture can usually be kept for about six months without having mold problems. At a higher moisture content, how long can soybeans be stored before mold becomes a concern?
Bill Wilcke, Extension engineer with the University of Minnesota, reports that as a guideline, soybeans in storage tend to act about the same as corn that is 2% greater in moisture content. For example, soybeans at 16% moisture could be expected to act like corn at 18% moisture.
Artificial drying of soybeans will be needed if soybeans are harvested and stored at a moisture content greater than 13%. The article "Soybean Drying, Handling, and Storage" by Bill Wilcke, Vance Morey, and Ken Hellevang discusses recommended options and guidelines, and is recommended reading if you need to dry soybeans. The bulletin "Natural-Air Corn Drying in the Upper Midwest" by Bill Wilcke and Vance Morey is also useful as many of the principles for drying corn will be similar for drying soybeans.
The soybean drying article, the natural-air corn drying bulletin and some other postharvest information can be found on the post harvest.