KEVIN SKUNES is a vice president at the National Corn Growers Association and a fourth-generation farmer outside Arthur, North Dakota. On his 6,000 acres, he currently raises about 55 percent corn, 45 percent soybeans. This constitutes a big change since Skunes was a child in the 1960s. Back then, the farm was about 2,000 acres of wheat, barley, sunflowers and soybeans, with no corn.

Farmers who had long rotated plantings among a diverse group of grains are increasingly turning to a single one. Corn has always been a mainstay of U.S. agriculture, but its increasing profitability has driven up corn's share of total production, while grains such as wheat, oats and sorghum have steadily fallen, according to a Bloomberg analysis of a half-century of crop data. This locks farmers, as well as machinery-makers including Deere & Co., to the rises and falls of one crop, as both domestic and export markets grow more and more tied to the dominant U.S. grain. That exposes farmers to greater volatility and greater trade risk if a major buyer, such as Mexico, were to decide to stop buying U.S. corn.

Corn will make up 68 percent of this year’s projected harvest of major U.S. grains and oilseeds this year, according to data the U.S. Department of Agriculture released Wednesday. That’s up from 47 percent in 1968. New markets and technology have made corn more profitable compared to other crops, which is why longtime farmers once devoted to competitive grains have switched to the nation’s number-one source for biofuels and cattle feed.

Find out more at www.ncga.com