The snow was piled waist-deep outside the Southern Manitoba Convention Centre as more than 400 farmers gathered to consider the once-unthinkable: growing corn on the Canadian prairie.

At one end of the packed auditorium last month in Morris, home of the Red River Wild hockey club, an Ohio farmer brought in by DuPont Co. opened a presentation with a slide that read “Ear Count 101.” At the other end, Deere & Co. showed off tractors and other equipment from a booth while Daryl Gross explained planters and corn dryers to curious men wearing seed caps.

“This is here to stay,” said Gross, who sells CNH Global NV tractors for Southeastern Farm Equipment Ltd. in nearby Steinbach, 40 miles north of the U.S.-Canada border. His customers are increasingly devoting acreage to corn. “There are a lot of guys who are experimenting with it and looking at it,” he said.

Corn is the most common grain in the U.S., with its production historically concentrated in a Midwestern region stretching from the Ohio River valley to Nebraska and trailing off in northern Minnesota. It had been ungrowable in the fertile farmland of Canada’s breadbasket. That is changing as a warming climate, along with the development of faster-maturing seed varieties, turns the table on food cultivation. The Corn Belt is being pushed north of what was imaginable a generation ago.

Growing seasons on the Canadian prairie have lengthened about two weeks in the past half-century. The mean annual temperature is likely to climb by as much as 5 degrees Fahrenheit in the region by 2050, according to Canadian researchers.

In Canada, that means amber waves of wheat are giving way to green fields of corn. Farmers sowed a record 405,000 acres of corn in Manitoba, Saskatchewan and Alberta last year, double the amount two years earlier and almost eight times what it was 20 years ago. That compares with 95.4 million acres sown in the U.S. last year.

The prospect of a Canadian Corn Belt has helped push farmland prices nationwide up 36 percent from 2007 to 2012, to $1,926 Canadian ($1,757 U.S.) an acre. U.S. farmland prices rose 22 percent in the same period, to $2,650 an acre.

Monsanto, DuPont move in

It has also drawn the attention of agribusinesses. Monsanto Co. and DuPont have boosted staff and invested more than $100 million in the region, hosting corn clinics like the one in Morris, a town of 1,800 about 25 miles north of the U.S. line, as well as research and development of seed varieties that can thrive in a shorter growing season.

“This is one of the few areas of the world where we are not growing corn and soybeans and have the opportunity to do that,” said Greg Stokke, western Canada business director for DuPont Pioneer, the company’s seed division. “We can adapt to the region, and after that the economics become attractive for the farmers.”

Pioneer, based in West Des Moines, Iowa, has more than doubled its staff in western Canada since 2008, and Pioneer and Monsanto have increased technical support for farmers trying new products.

Higher prices for the grain make it attractive to grow, even with the lower yields associated with shorter seasons, said Dennis Todey, an agricultural engineering professor at South Dakota State University in Brookings and the state’s climatologist.

“We’re getting more moisture out west, our seasons are getting longer, and that makes corn a more viable planting option,” he said. While the companies say they can increase acreage even under current conditions, warming “boosts what they’re doing.”

Expansion may be aided in the short run by the formation of an El Niño, a periodic warming of the Pacific Ocean, which the U.N.’s World ­Meteorological Organization said this week may be imminent. Such events, which occur every two to seven years, tend to make winters in western Canada warmer, potentially expanding the growing season.

The shift in climate, and crops, comes with risk. In 2012, the worst drought in the U.S. Corn Belt since at least the 1950s seared the crops of southern farmers, some of whom are shifting to more drought-resistant plants on the assumption that drier days are here to stay.

‘Brutal winter’

“We’ve just had a brutal winter, which leads some people to say, ‘Warmer summers, bring it on,’ ” Danny Blair, a professor of geography at the University of Winnipeg, said in an interview. “But there’s give-and-take in climate change, and in the end it may be more take than what it gives us.”

Global warming will increase the frequency of drought and erratic rainfall, he said. Insects and pests that don’t survive Canadian winters will have a better chance in the future, giving north-of-the-­border farmers some of the same problems their U.S. counterparts face, with less production to soften their losses.

“The less you do to mitigate climate change, the more unpredictable it will be,” Blair said. “We need to be talking more about mitigation, along with adaptation.”

Even with the shift in growing areas, climate change will cut global corn yields by about 1 percent a decade compared with what they otherwise would be, according to a study released March 31 by the U.N. Intergovernmental Panel on Climate Change. Improved technology and farming practices can mitigate those losses, the panel said.

Snow-drifted fields

When Andrew Knowles began growing corn near St. Andrews, Manitoba, about 20 miles north of Winnipeg, in 2008, everyone thought he was stupid, he said. “Now they come for advice,” he said.

Standing in snow that by mid-March had drifted more than 3 feet deep, Knowles said he has until the end of May to get his crop in. Some autumns, he’s had to harvest corn on snow-covered ground, putting the wet grain through dryers to make it sellable.

Still, short-season varieties, a little more heat, and lower land costs give him enough profit to compete with farmers farther south in the U.S., where crops are larger and farming is more expensive.

“In Illinois, what’s your cash rent for an acre? $300? Mine is $25,” said Knowles, who said he can make money with yields one-third the U.S. average and prices less than half what they are now. Know-how learned from his experiments and visits with farmers from the Dakotas help, he said. So does Mother Nature.

“The climate is changing in ways that benefit me, I think, because we’re having hotter summers,” he said. “For the corn, it’s just perfect. Heat and humidity. I like the hot summers.”

The government of Saskatchewan, Manitoba’s western neighbor, this year added corn as an insurable crop for farmers, prodding acreage growth. From there through Alberta and British Columbia, the trend toward waves of cornfields along the nation’s Trans-Canada Highway is heating up, Stokke said.

“Corn has been moving north and west for a long time because of the economics,” he said. “You look at world needs, and you’ve seen acreage expand for decades.”

“Farmers have a lot of choices,” he said. “In the end, this almost will sell itself.”