Wood ash

Soil Acidity and Liming
Clemson University

See: http://www.woodash.net/data/acidity1.pdf

Wood Ash: An Alternative Liming Material for Agricultural Soils
Alberta Agriculture and Rural Development

Many forestry facilities in Alberta use bark, sawdust and yard waste, commonly referred to as "hog fuel," to generate steam, electricity and heat for plant operations. There are also several facilities that use hog fuel as an energy source to generate electricity. More than 180,000 tonnes of energy system wood ash produced annually at pulp mills, sawmills, oriented strand board and fibre board plants is currently disposed of in industrial or regional landfills.

See: http://www1.agric.gov.ab.ca/$Department/deptdocs.nsf/all/agdex3435

NEWMOA FACT SHEET: Beneficial Use of Wood Ash on Agricultural Land
April 6, 2001, Northeast Waste Management Officals Association

This fact sheet is intended to provide general information to potential users of unadulterated1 wood
combustion ash as an agricultural amendment. It is the responsibility of the producer and user of the ash to determine the appropriateness of a particular application and to select applicable tests and
specifications to facilitate its use and environmental protection. Potential users of unadulterated wood
combustion ash on agricultural land should contact the appropriate state regulatory program to identify specific use conditions and permit requirements. A listing of state contacts is located at the end of this fact sheet.

See: http://www.newmoa.org/solidwaste/FSWoodAsh.pdf

Best Management Practices for Wood Ash as a Soil Amendment
Prepared by Mark Risse, Extension Engineer, Updated by Julia Gaskin, Land Application Specialist 2002, Cooperative Extension Service,The University of Georgia College of Agricultural and Environmental Sciences

Wood was burned in the United States in the 1700s through the early 1900s to produce ash for chemical extraction. The ash was used mainly to produce potash for fertilizer and alkali for industry. As other potash production technologies became more economical, the value of wood ash as a raw material dropped.

Recently, ash has been considered a waste product instead of a resource, because few industries have taken advantage of its beneficial properties. Approximately 3 million tons of wood ash are produced annually in the United States. While approximately 80 percent of all ash is land applied in the Northeast United States, less than 10 percent is land applied in the Southeast. The other 90 percent in the Southeast is landfilled. Several alternative uses for wood ash have been developed. Land application is one of the best because nutrients taken from the land during harvest are recycled back to the land. In a survey of more than 80 Southeastern paper mills, 60 percent of the respondents reported interest in land application of wood ash. Figure 1 shows the distribution of wood ash in Georgia. It is apparent that wood ash has potential to be used as a lime substitute throughout Georgia.

See Factsheet and attaches

Wood ash admixture to organic wastes improves compost and its performance
T. Kuba , A. Tscholl , C. Partl, K. Meyer, H. Insam
Agriculture, Ecosystems, Environment Vol 127 (1-2), August 2008 pp 43-49

A B S T R A C T
Throughout Europe, increasing amounts of wood ash are produced from biomass incineration plants. Most of these ashes are currently landfilled, despite their nutrient and micronutrient contents. The aim of this research was to find a way to return wood ash from biomass incineration plants into the natural cycle
of matter. Three composts from source separated organic waste were produced with 0%, 8% and 16% ash admixture. The composting process was monitored by in situ measurements of temperature and CO2 concentration in the windrows. Maturation of the composts was observed through the parameters basal respiration, microbial biomass,metabolic quotient, Corg, Ntot, C/N-ratio and plant growth tests with cress.

Mature composts were further analysed for potential pH, electrical conductivity as well as for nutrient (Mg, K, P) and heavy metal contents. The process indicators showed that ash admixture had no adverse effects and all legal standards were met. All produced composts met the requirements of the Austrian Compost Ordinance (Compost Quality A or even A+).

In a field experiment – a recultivation trial on an alpine ski-run – we compared the effects of the three composts with an organic fertilizer and a mineral fertilizer. Best plant growth was found on the compost amended plots, followed by the organic fertilizer. Soil respiration measurements indicated a better performance of composts amended with 8% or 16% ash as compared to compost that did not contain ash.

Concluding it may be stated that up to 16% ash admixture to organic wastes does not impair the composting process but is even able to improve the product quality. However, it has to be made sure that only bottom ashes of low heavy metal contents are being used and strict quality control is implemented.

See also:
From Substrate to application: Microbes do the Job Insam et. al. Feb 2008. "What changes are to be expected from Wood ash as an Admixture."

Purchase from Science Direct http://dx.doi.org/10.1016/j.agee.2008.02.012