(This factbox appears as part of a special package highlighting the global potash industry.)
Sept 22 (Reuters) - Potash was once of little interest outside the agricultural sector, but the crop nutrient has become a hot item, with pricing having outperformed other commodities during the boom and the subsequent downturn.
A small coterie of companies that control the vast majority of global potash production has maintained a tight rein on supplies and buoyed prices as emerging economies with growing food requirements have clamored for increased fertilizer supplies.
Here are a few facts about potash:
* The mineral, identified in the fertilizer world by the chemical symbol K, is one of the three main macro nutrients required by plants, along with nitrogen (N) and phosphate (P).
* Potash helps improve a plant’s disease resistance, crop quality and increases yields. It is the only potassium fertilizer source; there are no practical substitutes.
* Only 12 countries produce potash. Canada, Russia, Belarus and Germany account for more than 75 percent of global supplies.
* Eight companies currently control more than 80 percent of global supply: Potash Corp of Saskatchewan POT.TO, Mosaic Co (MOS.N), Agrium Inc AGU.TO, K+S SDFG.DE, Uralkali (URKA.MM), Silvinit SILV.RTS, Belaruskali, and Israel Chemicals (ICL.TA)
* Two marketing conglomerates control more than 60 percent of global potash exports. Canpotex is the overseas potash marketing arm of Potash Corp, Mosaic and Agrium, while Belarussian Potash Co is the export agent of Uralkali and Belaruskali. (Reporting by Euan Rocha; Editing by Frank McGurty)