"When you get a little bit more water and you're very conservative with that water, then you can go into crops like corn and soybeans that have a higher water use requirement," Hatfield said.
Climate scientists caution that as the Corn Belt expands northward in coming years, moisture will be a wild card. Temperatures are expected to continue rising, but the wetter trend is far from assured. Corn requires more water than wheat.
"All the models agree that temperatures in the Dakotas are going to warm pretty substantially over the current century," said Gene Takle, director of Iowa State University's climate science program and a coordinating author of the 2013 U.S. National Climate Assessment. "But the real question is whether the drying pattern that is very likely to intensify over the western half of the country is going to dominate."
Jolt for Wheat Markets
The expansion of corn in the Dakotas has had significant knock-on effects for farming and energy industries.
The chase for higher returns has meant a massive switch by wheat farmers to corn. North Dakota, the No. 1 U.S. wheat state at 8.530 million acres in 2010, fell behind Kansas in 2012 and seeded only 7.840 million, as its corn plantings rose 75 percent to 3.6 million acres.
"It's amazing," said Lee Weisbeck, vice president with Starion Financial, a bank in Bismarck, North Dakota. "West of the Missouri River has always been spring wheat and sunflowers. And now I've got some producers who are planting 50 percent of their crop into corn, which has never happened before."
Part of the switch has been due to better crop insurance for corn, bankers say. But there has also been a building boom in grain storage.
"When you start planting corn with traditional wheat growers, you get 40 bushel per acre wheat. Then you start getting 130-bushel corn, you need more trucks and bins," said Schott, the North Dakota producer.
The amount of licensed grain storage in North Dakota reached an all-time high this summer at 380 million bushels and topped 400 million bushels by January, the state's Public Service Commission said. South Dakota has 300 million bushels of licensed storage.
Railroads have also kicked into high gear to transport ethanol from the Dakotas to refineries especially on the West Coast.
Is the corn boom here to stay? Frayne Olson, an economist and crop marketing specialist with North Dakota State University Extension service, says weather will matter but not as much as prices.
"In the eastern third of the state, guys have made the move to corn and will keep it. The central third will flip ... If we get back to a drier cycle, a lot of that central and western portion will switch back and say corn is risky. But if you have $8 corn, that gets everyone's attention."
Schott, the North Dakota farmer, agreed. Climate change will have less immediate effect than price changes.
"Land costs have been going up pretty fast, so some of these crops are going by the wayside," said Schott, referring to plantings like canola or flaxseed. "With the young farmers coming in, it's all about the bottom line. If it's got red ink, they don't want to plant it."