Comparison of Soil Applied Flue Gas Desulfurization (FGD) and Agricultural Gypsum On Soil Physical Properties.

Gypsum can come from different sources. Agricultural gypsum is typically mined and used to supply calcium to crops.  Flue gas desulfurization (FGD) gypsum is a by-product of coal power plants.  Although their chemical formulas are the same, different trace elements and materials are present in them. Both types of gypsum can be applied to agricultural soil as amendments; however, questions remain if their effects on soils are similar. The purpose of this study was to determine the effects of different rates of FGD gypsum application to soil, and compare it to agricultural gypsum, fly ash and lime. Soil samples for bulk density and aggregate stability analysis were collected three years after application to a Bermudagrass (Cynodon dactylon  L.) hay stand. Additionally, soil electrical conductivity and penetration resistance were measured. Preliminary results show that FGD gypsum has a less pronounced impact on soil physical properties compared to agricultural gypsum. Results of this work will help determine the effects and benefits of FGD gypsum application to soil.