Many existing producers have argued that the current potash price of slightly below $400 a tonne -- although well above the historical average -- is too low to justify the development of new, or so-called greenfield potash mines.

Kerr, while declining to provide the anticipated capital expenditure requirements for the Jansen projects, said BHP believes that the economics continue to make sense for it to push forward on the development of Jansen.

"There has been a lot of talk around brownfield versus greenfield. One of the important points that we would like to make is that, in the long-term forecast, we believe there is room for both, and in fact both are needed," he said.

Kerr noted that although BHP is a new entrant in the potash sector, it has the skills and the balance sheet necessary to be successful.

"The combination of BHP's strength and ... the resource, gives us the opportunity to build a very competitive greenfield project," he said. "We see ourselves being in a position to be on the right side of the cost curve for a long time."

Eoin Treacy's view The exploitation of potash resources is a specialised endeavour and economic reserves are concentrated in only a few countries. To date, the oligopoly dominated by Potash Corp of Saskatchewan has been untouchable because of the high cost of entry. BHP Billiton is one of the few companies with the size, reach and balance sheet to be able to afford to gain a foothold in the historically profitable potash industry. This widely expected development at least in part helps to answer the question of how BHP Billiton plans to deploy its large cash reserve.

Potash and other fertiliser companies have pulled back rather sharply over the last three months but are looking overstretched and some have come back to areas of potential of support. Potash Corp of Saskatchewan, Agrium, Mosaic, SQM, Yara International, K+S, Incitic Pivot and Intrepid Potash bottomed in 2008 and are steadier today but there is no confirmation yet that the recent drift into underling support has ended and they may need firmer grain prices to act as a bullish catalyst. Upward dynamics, particularly if they occur across a number of these shares within a short period, would signal demand is beginning to regain dominance.

Western Potash, which is a smaller company and has yet to post positive earnings, has been forming a first step above its base for more than year and is currently rallying from the lower side of the range. A sustained move back below C37¢ would be required to question scope for some further higher to lateral ranging.