Belarus has raised export duty on potash fertilizers by 50% from June 1, a presidential decree showed on Friday, a move that is likely to hurt local producers. The duty will rise to €75/ton from the current €50, the decree published on official website www.pravo.by showed. BPC, a joint venture between Belarussian state firm Belaruskali and Russia's Uralkali, is the sole exporter of potash from Belarus and controls up to 30 percent of the global potash market.