Characteristics of wood ash and influence on soil properties and nutrient uptake: an overview

Wood industries and power plants generate enormous quantities of wood ash. Disposal in landfills has been for long a common method for removal. New re gulations for conserving the environment have raised the costs of landfill disposal and added to the difficulties for acquiring new sites for disposal . Over a few decades a number of studies have been carried out on the utili zation of wood ashes in agriculture and forestry as an alternative method f or disposal. Because of their properties and their influence on soil chemis try the utilization of wood ashes is particularly suited for the fertility management of tropical acid soils and forest soils. This review principally focuses on ash from the wood industry and power plants and considers its p hysical, chemical and mineralogical characteristics, its effect on soil pro perties, on the availability of nutrient elements and on the growth and che mical composition of crops and trees, as well as its impact on the environm ent. (C) 2001 Elsevier Science Ltd. All rights reserved.