Canadian Forest Service Publications
Regulations and guidelines for the use of wood ash as a soil amendment in Canadian forests. 2016. Hannam, K.D.; Deschamps, C.; Kwiaton, M.; Venier, L.; Hazlett, P.W. Natural Resources Canada, Canadian Forest Service Information Report GLC-X-17. 53p.
Issued by: Great Lakes Forestry Centre
Catalog ID: 37781
Availability: PDF (download)
Plain Language Summary
Ash is produced when wood (or ‘forest biomass’) is burned to produce bioenergy. In Canada, wood ash is often treated as a waste material and landfilled. However, wood ash is rich in important plant nutrients, such as calcium, magnesium, potassium and phosphorus. In some European countries, wood ash is applied to forest soils to replace the nutrients removed during timber and forest biomass harvesting; to counteract the effects of acid rain on soil acidity; to improve tree growth and to displace ash from the landfill. Provincial/territorial regulations and guidelines govern the types of materials that can be applied to the soil. In Canada, there has been little formal guidance developed specifically for soil applications of wood ash, and ash is rarely applied to forest soils. Regulations that were developed for soil applications of other materials (e.g., biosolids, compost, hazardous waste) also typically govern soil applications of wood ash, and these can be confusing and difficult to interpret. To help forest managers interested in applying wood ash on forest soils or ash producers interested in making their wood ash available for this purpose, we present information on the current guidance relevant to soil applications of wood ash for each province and territory in Canada. We also review the available guidance from those European countries where wood ash is often applied to forest soils to help ensure that wood ash is applied to Canadian forest soils in a safe, efficient and effective manner.