Gypsum is composed of calcium (Ca) and sulfur (S) – two of the essential nutrients that plants require to achieve optimum growth and reach their maximum potential. Gypsum offers many advantages for soil management practices in addition to being a valuable resource for plant fertility programs. We offer a high performance solution grade powder that growers can apply with confidence. Designed for efficient delivery and immediate uptake, this 325 mesh powder can be used in reservoirs, fertigation, drip irrigation, or spray applications. OMRI Listed®.