Mosaic Co., the country’s largest producer of phosphate and potash fertilizer, is skeptical that farmers will reduce fertilizer applications next season, despite  sharply higher prices. 

The company last week said that strong demand combined with tight supplies will motivate farmers to keep applying fertilizer to row crop acres in a bid to maximize yields.

“Our own belief is farmers like to farm, and they are not going to sacrifice yield by not fertilizing,” said Mosaic CEO James O’Rourk. “That’s not a good economic solution for profitability.”

On phosphate...