Farmers have claimed another fertilizer scalp. This time the biggest of the lot – that of PotashCorp.

Agrimoney.com warned in April that the Canadian giant risked getting hurt by its strategy of taking on its customers. PotashCorp kept potash prices near last year's inflated levels despite the slump in farm commodity prices, reckoning farmers' lust for potash would overcome their desire for slashing fertilizer bills.

Now the group is indeed licking its wounds. It has warned that second quarter earnings will come in as much as 50% below previous estimates, and 30% beneath even what analysts had prepared for, given the woes elsewhere in the sector. Oh, and at one-quarter of the level a year before.

Still a force to be reckoned with

Sure, that doesn't exactly leave PotashCorp on its uppers.

It will still manage earnings of nearly $1.9bn for the year, analysts' believe. Its shares are up 18% during 2009, better than most Western stocks.

Indeed, investors are likely to be pretty forgiving thus far to chief executive Bill Doyle.

Crucial talks

But that doesn't mean he is in an enviable position. The profits warning may not be the end of the fallout from its tough pricing strategy.

Farmers have shown that PotashCorp's power for wringing out potash payments may not be as strong as the group believed it to be.

That lesson will not be lost on the Indian and Chinese negotiators locked in longstanding price talks with PotashCorp over new three-year potash supply deals.

Both countries had looked to have something of a compromised bargaining position, given government desires to get agriculture moving.

Now PotashCorp has been shown vulnerable, they may feel more confident about their prospects of squeezing Mr Doyle for a better deal.