Nearly one-third of America’s farmland is devoted to raising corn (maïze) and that amount of corn needs an enormous amount of water. A problem is that most of the acreage is situated in areeas that are already prone to droughts. Remember the dust bowl, a period of severe dust storms that greatly damaged the ecology and agriculture of the US and Canadian prairies during the 1930s.
Now, scientists fear that these conditions might return with a vengeance. Continued climate change shall bring higher temperatures and water shortages to America’s farmlands. Already water scarcity and pollution are a growing threat to corn and therefore America’s economy.
Some 40% of the crop now goes for production of ethanol. Another 35% of the crop is grown for animal feed, but corn is used across the economy. The distillation of ethanol is only profitable with huge subsidies, while growing crops for animal feed is in itself a huge waste.
Despite new improved cultivars, corn plants are especially sensitive to heatwaves and drought. A recent report found that growers were having more trouble than initially expected in adapting to hotter and drier conditions.
Other crops suffer too. Production of chili peppers was sharply down in 2013: just 65,000 tons of peppers were produced in New Mexico in 2013 compared to nearly 78,000 tons in 2012. Because of dwindling rainfall, producers have to rely more and more on groundwater for irrigation, but the groundwater in the region is known for its high salinity.
And then we have not even mentioned the potential negative impact of the nearing El Niño.
 Wilcox, Piper: Water and Climate Risks Facing U.S. Corn Production: How Companies and Investors Can Cultivate Sustainability in Ceres - 2014
 Lobell et al: Greater Sensitivity to Drought Accompanies Maize Yield Increase in the U.S. Midwest in Science - 2014
 Hong, Kalny: Role of sea surface temperature and soil-moisture feedback in the 1998 Oklahoma-Texas drought in Nature - 2000