FLY-ASH AND LIME AMENDMENT OF ACIDIC COAL SPOIL TO AID REVEGETATION

A greenhouse study was conducted to evaluate the effect of fly ash on ameliorating the low pH of acidic coal mine spoils. All levels of lime and fly ash significantly increased the spoil pH, aboveground plant biomass, and root biomass. Topsoil placement over the spoil also generally increased plant biomass. Root growth in untreated spoil was limited to the depth of topsoil. However, when the spoil was amended with either fly ash or lime root growth occurred throughout the material. Fly ash and lime did not cause elemental toxicities to the plants, except for B. Although visual B toxicity symptoms and elevated levels of plant B were evident, no reduction in plant biomass occurred. The results indicate that fly ash is a feasible alternative to lime for treating acidic coal spoils in the region.