Sodic soil from Mississippi was treated with FGD gypsum at rates of 0, 1.5, 3.0, and 6.0 tons/acre, and then applied simulated rainfall to determine the ability of synthetic gypsum to reduce dispersion rates and erodibility. The data showed that the addition of FGD gypsum, at rates as low as 1.5 tons/acre, will substantially increase the stability of the surface soil and infiltration rates which result in lower surface runoff and erosion losses. The results indicate that FGD gypsum can be used effectively to remediate sodic soils, and that statistically significant improvements can be expected in the form of increased infiltration, and lower runoff and soil loss rates. The gypsum-induced increases in the larger sediment size distributions indicate that the quality of surface waters as the proportion of finer sediment in the runoff is diminished. Conslusion - FGD gypsum is at least as effective as mined gypsum for sodium-affected, dispersive soils.