Wheat and Soil Response to Wood Fly Ash Application in Contaminated Soils

Abstract

Wood fly ash from biofuel combustion plants is landfilled commonly as a waste, but research of this material is needed because it may reduce future fertilizer requirements. We investigated the effect of the ash application on potential changes in pH, nutrient, and potentially toxic element (in our case As, Cd, and Pb) content and mobility in soils. Wood fly ash in doses up to 1% (w/w) was added to spring wheat (Triticum aestivum L.) grown in potentially toxic element‐contaminated loam (Cambisol) and sandy clay loam (Fluvisol) soil material in 3‐yr pot experiment. The potentially toxic element contents in soils exceeded the maximum permissible limits for Czech soils, but the plant availability was, thanks to ash addition, limited. The effect of wood ash was greater in the Cambisol where Cd, Zn, and also Pb showed similar trends, and their content in plant decreased (Cd by 60%, Zn by 50%, and Pb by 45%), whereas the nutrient contents tended to increase in plants. Differences were usually insignificant (α = 0.05) in the Fluvisol between treatments, and Ca, Mg, and P contents were highest in the treatment without ash addition. The influence of soil changes on element uptake and distribution within the aboveground plant biomass was also observed. These findings are an important step on providing evidence of the benefits of using wood fly ash as a fertilizer supplement, because potentially toxic element contents in wheat grown in contaminated soils with ash addition were low and decreased, whereas the concentrations of major nutrients increased.