Testing soil for SCN

The SCN Coalition encourages soybean growers to know which fields have soybean cyst nematode (SCN) and at what population densities. Harvest is the ideal time to test soil for SCN.

SCN soil testing recommendations can vary by state, and some state soybean checkoff organizations have free soil sampling programs. Coalition experts encourage growers to get state-specific advice at TheSCNCoalition.com. “Successful management of SCN starts by knowing your number,” says University of Missouri Plant Pathologist Kaitlyn Bissonnette. “In Missouri, I recommend growers get a SCN egg count every three years.”

In a new video series titled “Let’s Talk Todes,” Bissonnette and Iowa State University Nematologist Greg Tylka explain why soil testing is the foundational element for managing SCN.

“In the Midwest, surveys have shown SCN to be found in 50% to 80% of fields,” says Tylka. “If a grower doesn’t know he or she has it and isn’t actively managing it, potential yield can be lost. After the results of the soil test are known, growers can select SCN-resistant soybean varieties and determine if a seed treatment is needed, or they might alter the rotation and slot in a second year of corn to try and reduce SCN population densities even more.”

Tylka says once SCN is detected, it will always be there at some level, which is why he encourages soybean growers to find it before populations explode. “It’s always there and it’s always going to be reducing yield. It might be 3 or 4 bushels per acre or it might be 23 or 24 bushels per acre. But you won’t know until you test your soil,” he adds.