More than 90 percent of phosphate and potash production is used to fertilize soil, increasing America’s crop yields in a sustainable manner. The United States produced $3.6 billion worth of phosphate and potash in 2013, supporting nearly 4,000 direct, indirect and induced jobs. Altogether, industries utilized all minerals to add more than $2.4 trillion to the U.S. GDP in 2013.
Below is an infographic from the National Mining Association which gives the basics for potash and phosphate.
I notice that the map in the infographic shows no production from Arizona. That may soon change. Recent discovery of potash in the Holbrook Basin has inferred reserves of 66 million metric tons of contained potash (K2O). See my post here.