Crop prices are set to remain firm well into next year, supported by yields depressed in part by low fertilizer applications, PotashCorp has forecast.

The world's biggest fertilizer group credited the kick-off in the grain price rally in early September to "concerns over global grain supplies".

Doubts over grain and oilseed output had emerged "as the combination of low potash and phosphate levels in the soil, and less-than-ideal growing conditions in key agricultural regions, muted crop yields".

America's forecast of a record corn yield of 164.2 bushels per acre was the exception rather than the rule, PotashCorp added.

Robust prices 

Crop prices would remain "supportive" heading into next spring, as the market squeeze followed through.

"With lower yields in many parts of the world putting pressure on global grain supplies, and frost and poor weather negatively impacting the US harvest, we believe that crop prices are likely to remain well above historical levels through the fall and winter," the group said.