Tender treatment protects soybean seed quality
Soybean seeds are tiny and delicate. To coax a strong, high-yielding plant out of the ground, you must treat seeds in a tender and cautious manner.
"Soybeans are more fragile than corn or wheat seed," says Mike Staton, Michigan State University Extension senior soybean educator. This is because soybeans have a thin seed coat—the first line of defense against pathogens and cold soil temperatures.
"A split or cracked seed coat will allow water to enter the seed too quickly," Staton says. "If you are planting into cold and wet soil, the moisture will get in rapidly and could cause cold injury and some cell damage."
The seed coat isn’t the only vital component that could be wounded by manhandling. Right beneath the seed coat is the embryo, the part of the seed that develops into a new plant. A swift bump or wild whack could harm the embryo, which might result in impaired root growth or seedling death.
To protect seed’s ability to develop into a productive plant, limit the distance that it falls. It’s better for seeds to fall on other seeds than metal equipment.
"The challenge of handling seed is that you are never improving the quality," says Doug Tigges, soybean genetics product manager at Syngenta. "If you want to break through the yield barrier, you have to make sure you’re handling your seed properly—like they are cartons of eggs."
Baby those beans. Staton and Tigges offer these tips to limit pre-plant soybean seed damage.
- Don’t sling soybean seed bags. Even a waist-high drop onto a concrete floor can reduce germination by up to 10%.
- Know the moisture level of your seed. The potential for damage to the embryo and seed coat increases as the moisture level declines. The optimum moisture range is 12% to 14%. Seed with moisture levels at or below 10% is extremely susceptible to injury and should be handled as carefully and infrequently as possible.
- Operate augers slow and full when handling bulk seed. This will help lessen seed bounce and excessive contact with the flighting edge and deflector nose.
- Limit seed drop. Reduce the height the seed falls from the conveyor or auger into the seeder or drill. Seed should not free-fall more than 4' to 5', and you want the beans to drop on other beans, instead of a steel surface.
- Make sure your equipment is in good working condition. Replace worn bearings and augers, as well as bent tubes. If an auger wobbles within the tube, seed damage is more likely.
- Install padding at the nose of the auger or belt conveyor to reduce impact when seeds exit the nose.
Weigh the pros and cons of bulk seed conveying equipment. Researchers at Ohio State University and Iowa State University say a belt conveyor is the gentlest, as long as the seed doesn’t strike a metal surface at the end of the belt. The next best alternative is a plastic or poly-cupped auger. Avoid metal augers when possible.