27 Sep Handling Soybean Maturity & Moisture Variation
September 27, 2013
Handling Soybean Maturity and Moisture Variation
Kenneth Hellevang, Ph.D., P.E.
Agricultural Engineer, NDSU Extension Service
Professor, Agricultural & Biosystems Engineering Department
North Dakota State University
Variation in soybean maturity and moisture in the field creates harvest and storage challenges.
Field losses, splits and cracked seed coats increase as moisture content decreases. Shatter losses have been shown to increase significantly when seed moisture falls below 13 percent and when mature beans undergo multiple wetting and drying cycles. Try to harvest as much of your crop as possible before the moisture level falls below 13 percent. Harvesting during high humidity or damp conditions may reduce shatter loss.
Unfortunately there has not been adequate research examining if green soybeans will change color in storage. Limited studies indicate that green soybeans will tend to stay green in storage. They do not lose their internal green color, although the surface color may lighten or mottle somewhat after weeks or months in storage.
Field losses need to be balanced against the discounts for green seeds in determining when to harvest. Another possibility, of course, is harvesting some of the field and leaving the portion with the green soybeans.
Soybean moisture variation may lead to storage and marketing losses. Operating an aeration fan will help to move moisture from wet beans to drier beans. Air going past wet beans picks up moisture, and that moisture will transfer to drier beans as the air goes past them. Moisture movement will be minimal without aeration airflow past the beans. Run the fan longer than is required to cool the grain to “even out” the moisture content. The moisture will not equalize, but it will become more uniform.