Canadian fertiliser giant Nutrien has warned it would be folly to invest in new high-priced potash projects like the one being considered by BHP in Saskatchewan with  established players in a strong position to dominate the market for at least the next decade.

Nutrien also revealed that only high gas prices and costs of production generally have stopped it investing in nitrogen and phosphate fertiliser plants in Australia, where it is the biggest player in fertiliser distribution and the biggest employer in agriculture as the owner of both the Landmark and Ruralco farm services businesses.