Short-term changes in spruce foliar nutrients and soil properties in response to wood ash application in the sub-boreal climate zone of British Columbia

Abstract

Utilization of wood ash as a forest soil amendment in British Columbia could have numerous benefits, including potentially increasing tree growth. Two wood-derived bottom ashes (low-carbon gasifier ash and high-carbon boiler ash) were applied at 5000 kg ha−1 (dry weight equivalent) with urea (100 kg N ha−1), in a two-way factorial randomized block design across two (18- and 24-yr-old) hybrid spruce (Picea glauca × engelmannii Parry × Engelm.) plantations in interior British Columbia. Changes in spruce foliar nutrients and selected soil properties were evaluated. After one growing season, foliar Ca and S significantly increased in plots treated with ash, and foliar N significantly increased while foliar Mg and P significantly decreased in spruce treated with urea. In LFH horizons, soil pH, exchangeable base cations (Ca, Mg, and K), strong acid-extractable B, and Ca significantly increased (p < 0.05) with ash addition; soil pH was greatest in plots treated with urea plus gasifier ash. No significant treatme...