For generations, farmers have used natural materials such as lime, gypsum and manure to improve their soil for growing crops. Now, a team of researchers led by the University of Missouri is giving new purpose to an established material — biochar, a charcoal-like substance made from leftover plant waste — and showing how it can address challenges facing today’s cotton growers. Even though biochar has been used in various forms of agriculture for thousands of years, this study focused on how it could help cotton farmers in the delta region of the United States, often called the Mississippi Delta.