Growth Response of Barley on Unweathered Fly Ash‐Amended Soil

Abstract

AbstractA clay loam topsoil that tends to form surface crusts was mixed with unweathered fly ash from a western Canada power plant in mixtures ranging from 0 to 100% fly ash (v/v). Barley (Hordeum vulgare L. var. Leduc) was grown on the mixtures in a greenhouse to examine the potential for phytotoxicity caused by trace elements in the fly ash. Plant emergence was delayed when ≥6.25% fly ash was added to the soil, however, it was not reduced unless ≥25% fly ash was added. The addition of 6.25 and 12.5% fly ash increased both plant height and grain yield while 25% fly ash produced similar plant heights and grain yields as the 0% fly ash treatment. Boron toxicity symptoms were evident in treatments with ≥6.25% fly ash and B accumulated in silage and straw to levels in excess of amounts considered adequate for most plant species. There was no reduction in yield, however, unless ≥50% fly ash was added to the soil. Adding ≤25% fly ash increased Se concentrations favorably in the grain, straw, and silage. Fly ash increased plant Mo concentrations to alter Cu/Mo such that it could be a concern for ruminant diets.