The world’s largest fertilizer users are the United States, China, India, Russia, and Brazil, according to The Fertilizer Institute.
Nitrogen: The United States is the world’s third-largest nitrogen producer after China and India. The United States has the capacity to produce nearly 14.5 million metric tons of ammonia. It both imports and exports nitrogen, but is a net importer. Russia is the world’s largest exporter, using fertilizer to raise foreign currency.

Phosphate: The United States is the world’s largest producer of phosphate fertilizer because of its large areas of phosphate rock reserves. It exports between 55 and 60 percent of its production. The top importers of phosphate fertilizer are China, Brazil, Canada, ­Australia, and India.
Potash: The United States produces some potash but is not a leader in potash production because of limited reserves. The world’s largest potash reserves are in Canada, which supplies most of the potash used in the United States.

SOURCE: The Fertilizer Institute