Corn Belt Shifts

Scientific American:

America's breadbasket isn't where it used to be. The epicenter of agricultural production has moved north and west over the past half-century, and that trend will likely continue at an accelerated pace due to global warming, a new study finds.
Published yesterday in the online version of the journal Nature Climate Change, the study depicts how such a shift could put new strains on U.S. infrastructure, as rails and trains replace riverboats as the primary mode of agricultural transportation.
"You're definitely going to need to expand loading and export facilities and bolster the strength of your rail lines from North Dakota west and east," said Bruce McCarl, a regents professor with the Department of Agricultural Economics at Texas A&M University. "This is a 50-year expansion we're talking about."
The agricultural sector already places significant demand on the nation's transportation infrastructure, making up 22 percent of all transport tonnage.
Of that total, grain holds the largest share. Yet even that could change, as evaporating temperature barriers allow corn production to expand in the rich soils of Minnesota and the Dakotas. Acre for acre, corn yields are three times as heavy as wheat... If infrastructure keeps pace with shifting production, the United States could play an even greater role in international food markets than it does today. While rising temperatures could unlock fertile areas of the Dakotas and Minnesota, as well as other Great Lake states and provinces, food production is set to decline in more equatorial regions of the world, leading to greater demand for U.S. crops.
The increased demand will require more export terminals, particularly in the Northeast and Northwest. Larger volumes of crops could be moved via the Great Lakes, though lower water levels there could raise transportation costs as well.

I think that long-term wheat production will disappear in this area.  It was slowly disappearing here anyway, but gradual warming will eventually cut down yields.