To properly store grain in Iowa, moisture content needs to be 13% to 14% for corn and 11% to 12% for soybeans, said Charlie Hurburgh, a retired Iowa State University Extension and Outreach grain quality specialist.
These recommendations are especially for storage extending into the summer months. For winter-only storage, 15% moisture for corn and 13% moisture for soybeans is acceptable. Maintaining cool temperatures (30 to 40 degrees F) with aeration during winter is critical.
Storage guidelines
If grain is stored above these recommended moisture levels (15% corn, 13% beans), it should be moved or dried when the cool temperatures can no longer be maintained.
Hurburgh advised following these moisture content guidelines:
- Corn. 13% to 14% for long-term or summer storage, 15% for short-term winter storage
- Soybeans. 11% to 12% for long-term or summer storage, 13% for short-term winter storage
- High-risk grain. Low-test-weight or damaged grain should be stored at 1% lower than standard recommendations.
- Aeration. Cool grain to 30 to 40 degrees F in the fall.
- Monitoring. Check grain temperature, moisture and odors every two weeks in winter and weekly in spring and summer.
- Cleaning. Remove fines (broken grain and debris) from the center of the bin to improve airflow and reduce spoilage risk.