Randy Dowdy, Valdosta, Ga., won the irrigated division in the 2012 National Corn Growers Yield Contest with a 372 bushel per acre entry. He shared some of his secrets to high yields at a session at Big Iron last week.

"The most important thing to see in your field…is your shadow," Dowdy said.

He said he walks every acre of corn on his farm.

"I walk with the crop consultant…I take soil samples with the crop consultant," he said.

Other advice from Dowdy:

Don't plant all your acres to one hybrid. He plants a dozen different hybrids every year.

Don't plant all your corn at the same population. Years can different. Different population spreads your risk.

Corn pours from the unloading auger during a recent harvest.

Don't plant all the same maturity, even if you could. He said that he saw ear tip back ranging from 0 to 4 inches on different hybrids this year. Hybrids react to the season differently and yield will be affected, even if the date they reach maturity isn't a factor.

Conduct your own tests. He devotes 20-30 acres each year to experiments. A seed company puts out a plot trial and he does his own comparisons of production practices. However, he's contest entries don't come from the acres he experiments on. They come from his production fields.

Don't always believe the experts. Dowdy said he was told that it wasn't worth trying twin row corn because the university had done it five years and hadn't seen a few additional  bushels per acre -- not enough to pay for the extra costs.. But they had only ripped the soil between the rows. Dowdy figured it might be different if they had ripped the soil under each row. So he rigged up a toolbar to rip directly beneath twin rows and increased his yields 30 bushels per acre.

"You have to keep an open mind and be willing to test new things," he said.

How high can corn yields go?

"I've seen 500 bushels/a on my yield monitor," he said.