Potash Corporation of Saskatchewan Inc. (PCS) was a Canadian fertilizer company based in Saskatoon, Saskatchewan. The company merged with Agrium Inc. to form Nutrien, in a transaction that closed on January 1, 2018. The company was the world's largest potash producer and the third largest producer of nitrogen and phosphate, three primary crop nutrients used to produce fertilizer. The company also produced animal feed supplements, industrial acids, and other products. The company had operations and assets in Canada, the United States, and Trinidad and Tobago.