An Assessment of Wood Ash on Perennial Forage Stands

Abstract

Agricultural soils in Nova Scotia are usually limed in order to raise soil pH to ensure optimum availability of soil nutrients. Wood ash, produced by burning wood-based fuels, is promoted as a substitute for agricultural lime. This study individually assessed two wood ash sources available to Nova Scotia producers through on-farm sampling as well as greenhouse bioassay and incubation experiments. The variables measured were soil pH, plant-available and total element concentrations in soil, total element concentrations in above ground plant tissue, botanical composition and pasture condition scores (PCS). Soil pH was significantly increased after the application of wood ashes, however the effect was short-lived for one ash (NewPage). Agricultural lime was the most effective at increasing pH. Total soil concentrations of Al, Cr, K and Na remained elevated one year after ash application to NewPage sites. Brooklyn Power ash contained excessive levels of Zn, Cd, Pb and As.