A reigning champion in the global fertilizer business, Mosaic Co. is getting into golf. It seems incongruous. But Mosaic sees a new high-end resort it is building near Tampa, Fla., as a good way to reuse a no-man's land of waste sand from its old phosphate mines.

Plymouth-based Mosaic and its corporate forebears have mined phosphate in Florida for decades. The mineral is a key ingredient in fertilizer, and it's clawed from the ground in giant strip mines.

Now, three prominent golf course designers have transformed 700 acres of old sand dunes into two courses at a resort dubbed Streamsong.

"We were looking at how we could most effectively put ourselves on the map -- to create an identity for Mosaic," said Rich Mack, the company's general counsel.

The company has poured "tens of millions" of dollars into Streamsong, which has been on the drawing board since 2007. While the project may appear to be far afield of Mosaic's core business, Mack pointed out that Streamsong will enable Mosaic to get a return on land that was idled.

The resort had a "soft opening" last week, and both courses are open for play. The grand opening is slated for Jan. 26, and a 216-room lakeside lodge is expected to be done in November.

Plans also call for hiking, biking and other activities on the Mosaic-owned site, which covers 16,000 acres a little more than an hour's drive from the Tampa airport.

Streamsong is separate from a settlement Mosaic made in February with the Sierra Club over environmental litigation that was blocking the expansion of a big Mosaic mine. Mosaic is donating to Florida or a nonprofit organization a 4,171-acre tract of land worth at least $10 million.

The company is the seventh-largest landowner in Florida and gets most of its phosphate there. The company was created in 2004 when Cargill Inc. merged its fertilizer business with IMC Global of Illinois, a publicly traded company. Cargill sold off its 64 percent stake in Mosaic in May 2011.

Land that's now home to Streamsong was mined in the 1960s. Since then, vegetation has grown over the waste sand dunes, creating a geographic effect not common in Florida, Mack said. No palms or palmettos, but no flatland either; instead, there are rolling hills and contours.

"It's big and bold and has to be a world-class venue, on par with any other venue in the United States," Mack said.

Tom Doak designed one of Streamsong's courses; Bill Coore and Ben Crenshaw, the other. Doak and the Coore-Crenshaw duo also designed courses at the Bandon Dunes golf complex in Oregon, well-known among links aficionados.

Playing a designer golf course doesn't come cheap. At Streamsong, 18 holes costs $130 to $250, depending on the season.

In central Florida, phosphate mining has long been an economic pillar. The area is akin to Minnesota's Iron Range, where iron ore mining is still an economic foundation, but doesn't pack the punch it once did.

As time goes on, mines become automated, leaving a smaller footprint with fewer workers. And old mines get played out, sometimes leaving scarred earth and ill will against their owners.

Streamsong's corner of central Florida has had little to show for itself economically.

"This development is significant because it's taking some of these lands and putting them back to use for economic purposes," said Rodney Carson, economic development director of Polk County, Fla.

Mosaic, still one of the region's major employers, is aware of the goodwill a project like Streamsong can generate. "We know it will be viewed favorably by our constituencies in the region," Mack said.

Mike Hughlett • 612-673-7003