Source: Yankton Press & Dakotan

Jim Nichols braced himself for a big number when he recently called his local grain elevator for a price on phosphate, a key ingredient of fertilizer. Even so, the Lake Benton, Minn., corn farmer and former state agriculture commissioner found himself laughing-nervously-after the fertilizer dealer told him the price: $1,025 per metric ton, up from just $520 a year ago. "It was humorous until I learned that he wasn't kidding," Nichols said. "Then I started to worry."

Indeed, in the eyes of many farmers and agricultural experts, fertilizer prices have seemed to defy the normal laws of economics. Despite the high prices, makers of phosphate and potash