"It’s important data is usable, which boiled down means it can be easily and reliably understood," says Steve Cubbage.

“All through the Midwest it’s been a drying season... It’s been a tight supply all the way across the board.”

The shutdown equates to about 250,000 tons of potash production.

They act as hosts for pests, affect soil temperature and can sequester moisture and nutrients from future crops.

Can growing international markets compensate for domestic demand shortfalls?