A view of the Uralkali main office in the city of Berezniki in the Perm region close to Russia's Ural mountains August 27, 2013. The global potash market faces short-term turbulence due to a dispute between major exporters Russia and Belarus before a definitive collapse of the sector's once-mighty cartel brings prices for the fertiliser ingredient down sharply. Belarus this week detained the chief executive of Russia's Uralkali, the world's top potash producer, accusing him of inflicting severe economic damage. Picture taken August 27, 2013.REUTERS/Sergei Karpukhin (RUSSIA - Tags: BUSINESS POLITICS AGRICULTURE)