Mixtures of Bottom Ash and Soil as a Growth Medium for Three Range Species

Abstract

Bottom ash from a coal-fired power plant was mixed with soil in varying proportions to determine its effects on germination, growth, and survival of blue grama (Bouteloua gracilis (H.B.K.) Lag. ex Steud.), western wheatgrass (Agropyron smithii Rydb.), and fourwing saltbush (Atriplex canescens (Pursh) Nutt.). Five ash-soil growth mediums were developed, ranging from 100% ash-0% soil to 0% ash-100% soil (control). Bottom ash had no significant effect on the percentage germination of western wheatgrass and fourwing saltbush, but germination of blue grama seeds was reduced by the 100% ash-0% soil treatment. Percentage survival of all three species was not significantly affected by any of the ash-soil treatments. The treatments did, however, exert a significant effect on height growth of all three species. Plant height usually increased as the proportion of soil in the mixtures was increased. In addition, control plants produced significantly more biomass than did plants growing in any of the ash-soil treatments. Some of the physical and chemical properties of the bottom ash may account for its deleterious effects on the growth of these three species. High pH, lack of adequate plant nutrients such as nitrates and potassium, and unfavorable structural characteristics of the bottom ash may have caused reductions in plant growth.