FGD Gypsum in Peanut Production.

Calcium is the major limiting nutrient for peanut production in the Southeast. Deficiency affects yield, grade, and seed quality. Lime and gypsum are calcium-containing soil amendments used in peanut production. Gypsum is frequently applied when pH adjustment is not needed specifically as a calcium source. Geologic gypsum sources are not common in the Southeast, but flue gas desulfurized (FGD) gypsum is available as a byproduct from coal fired power plants. A field trial was conducted in 2012-2015 at various sites in Alabama and Georgia to compare the use of various sources of gypsum for peanut production including geologic gypsum, FGD gypsum, and a gypsum byproduct from phosphorus mining. Results indicate no differences between FGD and geologic gypsum products in peanut yield, grade, and seed calcium. The byproduct from phosphorus mining was slightly less effective at providing calcium to the seed in one trial, but results were not consistent among peanut varieties for that site nor was decrease significant in other trials. Overall results indicate FGD gypsum as a good source of calcium for peanut production.