Heyworth students use a local farmer's field for their research trials. Jestun Nutter, the school’s FFA advisor, says the 23-acre field they use has sloping ground, which offers the students a chance to test strategies in both wetter and drier field spots.

"The field had been in continuous corn for nine years," he says. “Yield was declining, so the farmer suggested we put in a soybean plot. With the help of a local seed company rep, we decided to plant Beck soybeans with and without an inoculant. The seed company mixed the powdered product, Graph-Ex SA, with the soybeans. Our season was pretty dry. We saw a yield increase, but may have had higher yields in a good year."

Graph-EX SA has been commercially available for the last two growing seasons. Its bacteria live on plant roots, which Nutter says help protect against disease. Graph-EX SA is designed to expand the root system so the plant can increase moisture and nutrient intake.

"Graph-EX SA contains three strains of rhizobia bacteria and a strain of trichoderma with a patent pending from Cornell University. Of the rhizobia, one nodulates in cool soils, one works in warmer soils, and the third works in the presence of high nitrate levels from the previous corn crop," explains Dan Custis, president of Advanced Biological Marketing, the company that manufactures the product.

"Third-party research at Cornell and other universities shows an average 3-3.5-bu./acre yield increase in the Corn Belt, which provides about a 10:1 return on investment with soybean prices in the teens," he continues. "Farmers will see the most yield response on their marginal ground, but even good soils in central Illinois can see a yield bump."

Fabian Fernandez, University of Illinois soil fertility specialist, has not done any research with Graph-EX SA, but says general research with soybean inoculants shows that such products work best where soybeans have not previously been planted or not been planted in many years. He adds that soybeans have strong seed coats that keeps embryos safe and protects seed from dehydrating and abrasion from the soil.

Raben anticipates more farmers explore new management strategies to increase yields. "I think we could see more preplant strategies come back into play, especially as some of us put less emphasis on only post glyphosate treatments for weed control."