More than 80 percent of the country’s fertilizer is produced in the Midwest.

But a small number of states, including Illinois, Iowa, Minnesota, Ohio, and Wisconsin, have banned the import of fertilizer from those states.

The Midwest has become a prime dumping ground for the countrys worst chemicals, as the region produces roughly 40 percent of all agricultural chemicals, according to the U.S. Department of Agriculture.

In a 2013 report, the agency found that fertilizer produced in Wisconsin, Iowa and Minnesota had a combined value of more than $200 billion annually.

In Illinois, fertilizer has also been blamed for the state’s air quality woes, with some residents experiencing respiratory illnesses after inhaling the chemical.

In the Midwest, many growers rely on the chemical to meet their needs for fertilizer, which they use to produce crops.

And despite the ban, the U’s Food and Drug Administration has continued to issue permits for the importation of fertilizers, and the U has become increasingly reliant on the Midwest as the source of fertilization.

The USDA, however, has warned that some farmers will face “a financial burden” from the ban if the states refuse to allow imports.