Brant Voss is a believer that high plant populations lead to high corn yields. His theory was proven to be accurate last year as the 26-year-old farmer from Dexter emerged as one of Iowa’s four state winners in the 2018 National Corn Yield Contest sponsored by the National Corn Growers Association.

Voss harvested a contest yield of 306.34 bushels per acre to claim top honors in the non-irrigated conventional tillage division.

“One of the things we did is really pushed our populations,” said Voss, who farms with his dad, Brent. He said...