Record summer heat rose like a fever along the U.S. grain belt and heightened into a national drought in July, causing a federal crisis that’s making farmers, politicians, consumers and international importers sweat.

Once-rich topsoil has crumbled into dust in over three-quarters of the country’s corn and soybean fields, and farmers are mowing over their crops in surrender. Already the worst drought in almost 50 years, the U.S. Department of Agriculture has designated over 1,300 counties as natural disaster zones.