Gypsum (calcium sulfate) for agricultural use can be sourced from mines or from scrubbers in coal-burning electric power plants, also known as flu-gas desulfurization (FGD) gypsum. Chemically, both sources are very similar but FGD gypsum tends to have a smaller particle size unless it is pelletized. Gypsum in general can be used as a sulfur or calcium source to crops. Flue-gas desulfurization gypsum specifically has been shown to reduce phosphorus losses in runoff under certain conditions. This session will cover agronomic uses as well as environmentally related uses of gypsum.