It seems like eons that we've watched the world's three biggest mining companies, BHP Billiton (NYSE: BHP), Brazil's Vale (NYSE: VALE), and Rio Tinto (NYSE: RTP), do battle with Chinese manufacturers over the price of iron ore, a key ingredient in steel production.

Now at least two of the three have turned their sights to fertilizer -- primarily potash -- that the world needs in rapidly increasing quantities to feed growing and developing populations. This adventure, which also includes Chinese interests, could be even more exciting than the earlier skirmishes. As we're told prior to TV commercial breaks, don't go away.

BHP starts it off
The attention to fertilizer isn't brand-new with the big miners. However, it picked up steam last month when the largest of the three, Melbourne, Australia-based BHP, tendered a $130-per-share cash offer to the board of PotashCorp (NYSE: POT), the world's biggest potash producer. Potash is particularly important to farming since it replenishes soil that has been depleted by prior crop production, thereby increasing future yield.

It didn't take the Canadian company's board long to turn up their noses at the $38.6 billion offer, calling it "grossly inadequate." At that time, BHP, which produces an array of metals and minerals from aluminum to zinc, immediately circumvented the board, taking its offer directly to the company's shareholders. That's called "going hostile," and its results are still unknown.

Is China joining in?
China, one of the world's major importers of potash as it endeavors to feed its huge population, hasn't been idly watching events in Australia and Canada. Indeed, as I've told you previously, state-owned chemical company Sinochem Corp. has retained HSBC to assist it in ferreting out its options regarding PotashCorp. And Hopu Investment Management, a Chinese private-equity fund, has spent time considering making a bid of its own.

Further, according to Wednesday's Wall Street Journal, Sinochem has approached Temasek Holdings with an eye toward forming a bidding group. Sinochem's apparently high activity level regarding PotashCorp likely stems from the Canadian company's owning 22% of Sinochem's fertilizer unit, Sinofert Holdings.

Beyond that, given concern in Canada about the impact of a major company being completely owned by Chinese interests, the possibility of a blocking bid has been raised. Aluminum Corp. of China (NYSE: ACH) attempted that approach a couple of years ago when it teamed up with New York-based Alcoa (NYSE: AA) to buy a significant stake in London-based Rio Tinto, when the big miner was in BHP's sights. The thinking is obviously that a minority stake would be more palatable in Saskatchewan, while simultaneously making BHP's efforts more difficult.

Vale's not interested
But what about Vale as a potential bidder? While the Brazilian company has an avowed intention of growing its own nascent fertilizer operation, Vale Fertilizantes, to the point where it becomes the world's biggest fertilizer supplier, and while it continues to look at smaller fertilizer companies, acquisitions the size of PotashCorp clearly aren't in the cards.

Nevertheless, at this week's end, Vale will combine Fosfertil SA, a fertilizer concern in Brazil, for which Vale paid $3 billion in May, and Bunge's Brazilian operations, for which it plunked down $1.7 billion. The combination of assets will become Vale Fertilizantes, which Vale CEO Roger Agnelli recently called "a vehicle for growth."

Vale's intention is to grow its potash operation by a factor of 10 during the next seven years, such that it will be producing 10.7 million tons annually, placing it behind PotashCorp and Minnesota-based Mosaic (NYSE: MOS), each of which produces more than 15 million tons annually. During the same time frame, however, Vale also intends to expand its production of phosphates to about 19.2 million tons annually.

Don't bet against BHP
But more importantly in the short term, what will be the ultimate disposition of the big Saskatchewan potash producer? You can see that the company is surrounded by more attention and interest than a typical beehive. At the same time, I've long been a fan of BHP for its management strength and its product diversity -- which includes greater leaps into the world's petroleum picture.

For those reasons, as well as its deep pockets, I'm betting that the Aussie company ultimately will come away with the Canadian treasure. At the same time, I'd urge all Fools to maintain a ranking position for the big miner on their watch lists. 

Fool contributor David Lee Smith doesn't own shares in any of the companies mentioned above. Try any of our Foolish newsletter services free for 30 days. True to its name, The Motley Fool is made up of a motley assortment of writers and analysts, each with a unique perspective; sometimes we agree, sometimes we disagree, but we all believe in the power of learning from each other through our Foolish community. The Motley Fool has a disclosure policy.