China typically buys close to half of the soybeans grown in the U.S. But the ongoing trade war means farmers in the Midwest must consider other options — and none are as profitable.

Popcorn festivals and even "popcorn capitals of the world" dot the middle of the country. Yet this ubiquitous snack is grown on fewer than 1,000 farms in the U.S. today.

Along with calls for better disaster mitigation programs, the mayors announced a new federal data tool that will compile information on drought, flooding and river levels.

Quick-growing blooms of bacteria and algae have long been a hazard in lakes and rivers, because of the toxins they produce. Fueled in part by agricultural runoff, these blooms are also threatening public water systems, making water temporarily unusable, and forcing some cities and towns to take costly preventive measures.