Emerging markets are fertile ground for potash producers.

Mosaic (nyse: MOS - news - people ) and Potash Corporation of Saskatchewan (nyse: POT - news - people ) said Wednesday that Chinese customers had agreed to pay $576 per ton for potash this year, a gargantuan increase from $176 per ton in 2007. The accord was for 1 million tons and was signed by Canpotex, a marketing compay for Saskatchewan potash producers, and the Chinese agency Sinofert.

"We are pleased that Canpotex has finalized negotiations with our Chinese customers and we look forward to resuming shipments to them soon," stated Jim Prokopanko, Mosaic's Chief Executive Officer.

Shares of the Minnetonka, Minn.-based fertilizer company were up 4.8%, or $6.17, to $133.77, in afternoon trading. Potash's shares were up 7.7%, or $14.11, at $198.52. Another Canpotex member, Agrium (nyse: AGU - news - people ) rose 8.7%, or $6.88, to $85.80.

Wednesday's announcement reflects rising demand for the fertilizer in emerging markets, as well as increasing production of ethanol for use as a gasoline replacement. (See: "Mosaic's Fertile Future")

BMO Capital Markets analyst Edwin Chee said recently: "We believe that phosphate and potash producers like Mosaic will continue to experience rising fortunes and we continue to rate the stock outperform. In the event that the stock market chooses to react negatively, we would recommend buying the stock on price weakness."