Inoculants can protect plants during periods of extreme weather.
Weather extremes at planting—both too little and too much moisture—signal that soybeans may benefit from the use of a commercial inoculant this season.
Russ Berndt, Becker Underwood product manager for legumes, encourages soybean growers to use an inoculant, given the see-sawing weather extremes across the country. He says bacteria, called rhizobia, in a high-quality inoculant are able to partner with soybeans to boost nodulation and fix nitrogen.
"This leads to a more robust root structure, better nitrogen fixation and more yield potential," Berndt says.
Becker Underwood reports that its Vault HP seed inoculant contains a patented growth enhancer to support increased nitrogen-fixing nodules. With its use, Berndt says soybean growers can expect a five-to-one return on investment roughly 50% of the time and a two-to-one return on investment more than 70% of the time.
University Extension specialists say they typically see less dramatic results from the use of a soybean inoculant.
Vince Davis, University of Wisconsin cropping systems Extension specialist, says a 1-bushel-per-acre yield increase is common.
However, he adds: "With $13 bu. per acre beans and a $2 to $4 per acre cost, it takes very little yield benefit to pay for itself."
The potential payoff from a soybean inoculant increases under any one or more of these five scenarios, according to Iowa State University Extension research:
- The field has never been planted to soybeans
- Soybeans have not been grown in the field in the past three to five years
- The soil pH is below 6.0
- The soil has a high sand content
- The field has been flooded for more than a week, creating anaerobic conditions
Bear in mind that not all inoculants are created equal, and their efficacy can vary considerably, notes Alex Johnson, LG Seeds field agronomist. He adds there are many different inoculant products available on the market for farmers’ consideration. In an online blog, he writes that "many can be mixed in the seed box with the seed or applied as the soybeans are transferred into the planter. Another convenient option is inoculants that are applied in combination with the talc or graphite that is already being used as a lubricant in the seed hopper by many farmers."
Regardless of the product selected, Berndt says growers need to use an inoculant with a guaranteed high rhizobia count. In the following video, he addresses how soybean producers can select a high quality inoculant and then evaluate its performance during the growing season.
Watch the video