SCN favorite soil types
Soybean cyst nematode, or SCN, is enemy number one for soybean producers. It’s a small, plant-parasitic round worm that attacks the roots of the plant and causes significant yield losses. There are ways to control the pest, but there is one factor that you may not have much control over. It’s your soil type.
Greg Tylka is an extension nematologist at Iowa State University. He says although SCN can infest any soil type, there are two types of soil that the nematode especially thrives in. The first one is high pH soil.
"If we start with the same number of SCN eggs in a high pH soil and a medium pH soil, we’ll get more reproduction in the high pH soil. I’m defining high pH as 7.5-7.8, even 8.0 whereas medium pH would be around 7," says Tylka. We don’t understand the mechanism for that, but it’s quite consistent throughout the upper Midwest."
The second soil type that SCN loves is sandy soil.
"We don’t know the mechanism of that either, but it reproduces extremely well. Also, the plants will suffer more yield loss because of that reproduction but also because sandy soil doesn’t hold water and nutrients very well. So, it’s kind of a double whammy," he says. "You have a stressful, physical soil environment that drains very quickly and doesn’t hold nutrients, and then the nematode is reproducing very well."
In general, the high pH soils tend to be heavier soils and have good fertility, but still allow high nematode reproduction.