Main content area

Growth of forages on acid soil amended with flue gas desulfurization by-products

Clark, Ralph B., Zeto, Sheila K., Ritchey, K. Dale, Baligar, V.C.
Fuel 1997 v.76 no.8 pp. 771
forage crops, industrial byproducts, industrial wastes, soil amendments, acid soils, plant growth, dry matter accumulation, application rate, calcium sulfate, forage grasses, Dactylis glomerata, Panicum virgatum, Tripsacum dactyloides, Trifolium repens, Medicago sativa, limestone, calcium carbonate
To assess beneficial or detrimental plant growth effects when flue gas desulfurization by-products (FGD-BPs) are applied to acid soil, experiments were conducted in a greenhouse to determine growth of forages (orchardgrass, tall fescue, switchgrass, eastern gamagrass, white clover and alfalfa) on an acid pH 4.6 soil with different levels of three FGD-BPs and chemical-grade calcium carbonate (limestone), calcium sulfate and calcium sulfite. The FGD-BPs tested were high-CaSO4, high-CaSO4 enriched with Mg, and high-CaSO3. Maximum total plant dry matter (DM) was obtained when approximately 25% of high-CaSO4 FGD-BP or approximately 2.5% of high-CaSO4 FGD-BP + Mg was incorporated into soil mixes; DM decreased at higher levels of addition. High-CaSO3 FGD-BP benefited growth of all species when added at levels up to approximately 3.0% in soil mixes. Beneficial plant responses were higher for the high-CaSO4 FGD-BPs than for the high-CaSO3 FGD-BP. Maximum beneficial plant responses for limestone were at approximately 0.25-0.50% and for CaSO4 at 50-75% in soil mixes, which were comparable with the high-CaSO4 FGD-BP and high-CaSO4 FGD-BP + Mg responses. Chemical-grade CaSO3 gave no beneficial growth effects on any of the plant species. The FGD-BPs used in this study benefited forage growth when added at appropriate levels.