Earth Policy Institute.
Over the last five years, Iowa has produced an average of 57 million tons a year to Canada's 49 million tons. Iowa's grain is all corn, Brown says. Canada's is all wheat, which is far less productive per acre. Iowa produces four tons of grain per acre, compared to 1.4 for Canada.
Iowa also produces almost as much soybeans as China does on less than half as much land, Brown says. Iowa produced 13 million tons of soybeans last year from 10 million acres. China produced 15 million tons on 22 million acres.
"Iowa is at the heart of the U.S. Corn Belt, a phenomenally productive piece of agricultural real estate. It enables the United States, with only 4 percent of the world's people to produce 40 percent of the world's corn and 35 percent of its soybeans," writes Brown.