Today’s Tessenderlo Kerley is the descendent of The Kerley Chemical Company, founded by four brothers who recognized a growing demand for sulfur plant nutrition in Pecos, Texas, shortly after the end of World War II. The Kerley Brothers developed a unique process for manufacturing sulfur-based liquid fertilizers that are safe, easy to handle and can be applied through irrigation equipment. In the early 1950s, Kerley Chemical opened retail stores and began selling fertilizers to farmers, retailers and distributors throughout the western United States and midwestern corn belt.  Acquisitions, ownership changes and growth guided the company through the years, while TKI established itself as a leader in the production and marketing of specialty products used in the agriculture, mining and process chemical industries.  TKI is now the world’s largest producer of sulfur-based thiosulfate fertilizers.With headquarters in Phoenix, Arizona, Tessenderlo Kerley, Inc. (TKI) produces and markets specialty chemical solutions, including fertilizers, crop protection chemicals and process chemicals and services to diverse markets around the world. TKI operates 11 manufacturing plants in North America in addition to an extensive terminal network. In 2017, TKI celebrates its 70th anniversary.  Tessenderlo Group is a worldwide specialty company, focused on food, agriculture, water management and on valorizing bio-residuals. The group employs about 4,900 people and is a leader in most of its markets, with a consolidated revenue of 1.6 billion EUR in 2016.