Soybean maturity, moisture variations pose problems
“Field losses, splits and cracked seed coats increase as moisture content decreases,” North Dakota State University Extension Service agricultural engineer Ken Hellevang says.
“Shatter losses have been shown to increase significantly when seed moisture falls below 11 percent and when mature beans undergo multiple wetting and drying cycles.”
He recommends producers try to harvest as much of their crop as possible before the moisture level falls below 11 percent. Producers will receive the best price for their soybeans when the moisture content is 13 percent. Prices will be discounted for beans at moisture contents exceeding about 13 percent, and beans are prone to storage problems at higher moisture contents.
Because harvest loses increase dramatically when the moisture content is below 11 percent, harvesting during high humidity or damp conditions may reduce shatter loss, according to Hellevang.
“Unfortunately, there has not been adequate research examining if green soybeans will change color in storage,” he says. “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. An other possibility is harvesting some of the field and leaving the portion with the green soybeans unharvested, Hellevang says.
Soybean moisture variation also may lead to storage and marketing losses. Operating an aeration fan will help 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. Hellevang suggests running 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. — WLJ