Kim Chipman and Megan Durisin Bloomberg News Corn prices in Chicago sank to a seven-week low as broken grain elevators and power outages in the U.S.’s busiest agricultural port raised concerns about grain supplies with nowhere to go. Hurricane Ida left more than 1 million homes and businesses without electricity in southern Louisiana and also shuttered export terminals in New Orleans. Food supply chains were already under severe pressure amid the pandemic, with shortages of everything from packaging to truck drivers. The U.S. is the world’s biggest corn supplier and about two-thirds of its grain and soy exports exit through ports surrounding the southern metropolis. If disruptions linger, it could cause a supply glut just as growers in the Midwest Corn Belt start harvesting crops. “Boats, barges, fleets are a mess and will take some time to get any flow back running,” Advance Trading Inc.’s Drew Moore said in a …