It’s been anything but a normal crop year.

“Most corn and soybeans were planted late, and that puts them behind in heat units,” says Charles Hurburgh, Professor of Agri­cul­­tural and Bio­­­­­systems Engineering at Iowa State University. “So the odds are favoring not fully mature grain for harvest.”

Of course, that depends on September and October weather, adds Hurburgh, but it is likely grain this year will be wetter and less mature.

The alternative is not terribly attractive, either. “We don’t want a lot of heat to gain back the heat units,” Hurburgh explains. “Hot,...