Some people can move markets with a word. Vladislav Baumgertner, chief executive of potash producer Uralkali, caused upheaval in the world of fertilisers yesterday with his announcement that his company would quit the marketing cartel in which it participates. The move sent the share prices of potash producers tumbling. PotashCorp, K+S and Mosaic all fell about 20 per cent.

Uralkali intends to market potash on its own and focus on expanding volumes. That is dreadful news for an industry that has traditionally managed prices by tightly controlling supply. Uralkali left the BPC export association having complained that it was in “deadlock”, blaming Belaruskali, another participant, for making deliveries outside their joint venture. By marketing potash directly, Mr Baumgertner said prices could fall from $400/tonne to below $300/tonne. A few years ago prices neared $900/tonne.

This is despite the fact that long-term demand remains intact. While some potash markets have softened this year, the global market is expected to expand about 5 per cent to 56m tonnes. And it should grow further as demand for meat in Asia drives the need for grain and fertiliser. Canada and eastern Europe, including Russia, are the biggest producers of potash, but Asia is the biggest consumer, accounting for about half of global demand.