Although the earth contains enough potash to meet the increased global demand for crop production  and U.S. supplies are likely secure, some regions lack potash deposits needed for optimal food crop yields. According to a recent USGS global assessment of potash resources, the costs of importing potash long distances can limit its use and imports are subject to supply disruptions.

“Global scarcity is not the issue with potash – transportation costs are,” said USGS scientist Greta Orris, who led the assessment. “We chose to assess potash because it is used primarily for fertilizer and with the increasing global population, the need for agricultural lands to be increasingly productive will continue,” said Orris.

The U.S. imports more than 80 percent of the potash it uses, mostly from the Elk Point Basin in Saskatchewan, Canada. The Elk Basin is the world’s largest source of potash, having provided at least 20 percent of the world’s potash supply for nearly 40 years.

The U.S. produces potash from deposits in Utah and New Mexico. While production from the Michigan basin recently ceased, a large potash resource exists there.  Production and development of resources in Michigan have been hindered by low potash prices, dated production equipment, and poor transport infrastructure amongst other factors. A significant potash resource in Arizona has also been identified, but resources in other states tend to be relatively small.

This global assessment, which includes a summary report and accompanying database, is the most complete, up-to-date, GIS-based, global compilation of information on known and potential potash resources from evaporite sources. The database includes more than 900 known potash deposits with measured resources. It also outlines 84 tracts throughout the world where undiscovered future resources might be found.

“A significant finding of this assessment is that there appears to be little to no potential to develop potash mines in either China or India, where large populations create the need for highly productive agricultural land, which in turn requires large amounts of appropriate fertilizers,” said Orris. “High import costs have resulted in lower usage of potash fertilizers than commonly seen in the U.S., and the potential for the land to be less productive.”

Potash includes a variety of minerals, ores, or processed products that contain potassium, one of three primary plant nutrients essential for growing food crops and biofuels. Modern agriculture requires large quantities of potassium so crop production is adequate to feed a growing population as arable land acreage becomes more limited. While potassium can be derived from other sources, conventional potash deposits – those formed by evaporation -- are the only cost- effective source for large quantities of potassium needed for high-yield agriculture.

The known deposits include location, geology, resource, production and other descriptive information. Potash-bearing basins may host tens of millions to more than 100 billion metric tons of potassium. Examples include Elk Point Basin in Canada, the Pripyat Basin in Belarus, the Solikamsk Basin in western Russia, and the Zechstein Basin in Germany.

The biggest potash producers are Canada, Russia, Belarus, and Israel. In addition to China and India, other areas lacking conventional deposits include much of Africa, Australia, and South America.

For the 84 tracts, the quantities of undiscovered resources are not estimated in this report. Instead, the tracts are classified into six categories that rank their potential to provide potash resources in 25 to 50 years based on known resources in the tract, level of available information, and whether geologic or other deficiencies, such as lack of water, power, or other infrastructure, could prevent or delay development of deposits. Potash tracts that may have potash deposits in production within the next five years include those in Ethiopia and the Republic of Congo.

More information on global and domestic potash, including demand, production, and uses is available from the USGS.