Feasibility of Flue-Gas Desulfurization Gypsum Applications to Wisconsin Soils for Reducing Phosphorus Losses.

Freshwater ecosystems are sensitive to phosphorus pollution. Although several phosphorus sources contribute to this problem, in Wisconsin agricultural soils are a significant factor. Flue-gas desulfurization gypsum (FGDG) application to soil has been shown to have the potential for reducing phosphorus losses but has not been studied in detail for Wisconsin soils. Comparison of water extractable P (WEP) for FGDG treated versus non-treated soils can be used to determine the impact of FGDG application. Application of FGDG for several tested soils did reduce WEP when compared to untreated control soils. This indicates that the FGDG treated soil had lower WEP concentrations compared to non-treated soil with similar Bray P1 concentrations. However, FGDG application had no impact on other studied soils. These results indicate the need for additional research to explain the mechanisms in which FGDG application could reduce WEP and thus P runoff losses.