Wood ash is an effective liming material, and research and development of the use of wood ash derived from the forestry industry on acid agricultural soils in northwestern Canada is needed. Wood ash (WA) at 3 Mg ha-1 was compared to 3 Mg ha-1 of agricultural lime (AG) and an unlimed treatment (check) on a clay loam soil with an initial pH of about 4.9. The replicated plots were seeded to a barley-canola-pea rotation, and to timothy grass and creeping red fescue for 3 years. Crop and hay production decreased in the order: WA > AG > check. Soil pH decreased in the order: WA = AG > check. Available soil P also decreased in the order: WA > AG > check. The effect on pH and available P was greatest in the 0-5 cm depth, less but still significant in the 5-10 cm depth, and not significant below 10 cm. The effect of water infiltration and soil aggregation, as measured by mean weight diameter, was: WA > AG > check. It is concluded that wood ash applied at 3 Mg ha-1 increased crop production and improved some soil chemical and physical properties.