About 58 percent of California is currently in the worst of the four drought levels used by experts, in conditions normally seen only once every 50-100 years.
The truce begins Friday morning local time. Envoys will travel to Cairo to negotiate a possible longer peace deal.
China has been a big and growing market for U.S. corn. But then farmers started planting a kind of genetically engineered corn that's not yet approved in China, and the Chinese government struck back.