Efficient Delivery and Immediate Uptake Ultra fine and highly reactive, Calcium 96 is a natural limestone powder that provides immediate availability of this valuable nutrient for plants and microflora. With a high neutralizing value, this solution grade powder can be applied at rates lower than typical Ag lime for fast soil pH changes. High quality calcium provides a myriad of benefits to plants, soils and soil biology. Designed for efficient delivery and immediate uptake, this 325 mesh powder can be used in drip irrigation or spray applications. Derived from: Limestone Listed by the Organic Materials Review Institute for use in organic production.