Soybean row spacing
Soybean row spacing preferences vary with 15-inch and 30-inch rows the most common. Equipment plays a large role in that choice. The increasing width of planters means that splitting rows with additional units makes planters very heavy. Opting not to split large planters means that both corn and soybeans are typically planted in 30-inch rows.
University of Illinois crop sciences professor Emerson Nafziger says this may dictate how you get planting done in the most cost-effective way.
"If I’ve got 1200 acres, 600 of corn and 600 of soybean and I only want to own one planter, I would probably have maybe a 16-row that has split units on it. If I can get efficient planting done and keep soybeans in 15-inch rows and corn in 30-inch rows, that’s what I would like to do," says Nafziger.
Most producers recognize that going from 30-inch rows to something narrower is probably going to give you a yield boost, which he says in most cases is about two bushels per-acre. But that doesn’t automatically mean you should stick to 15-inch rows no matter what. A disease called “white mold” can be a problem.
"It thrives when the canopy is sort of closed in and there’s not much air movement down toward the soil surface. I don’t know if we have a very good estimate of how much more white mold disease there is in 15-inch rows. It depends on where you are," he says. "Farther north in the corn belt it’s a little bit more common."