In New England and eastern Canada, wood is a plentiful, renewable resource.  It has long been burned for home heating, and, since the 1970's energy crisis, several large wood-fired electricity generating plants have gone online.  For example, the Tractebel-owned Pinetree Power plant in Tamworth, NH, is a 20 megawatt (MW) power plant that burns clean wood chips.  As interest and investments in renewable energy increase, more such "biomass" electricity generators are being built. 

In addition to electricity, these power plants produce wood ash.  Like wood ash from a home fireplace or wood stove, this industrial wood ash is rich in potassium (K), one of the three essential plant nutrients, and several micro-nutrients.  It is also alkaline, making it a valuable substitute for agricultural lime used to increase the pH of soils to provide optimum growing conditions. 

Most of the bulk wood ash produced in the region is sold and used as a soil amendment.  Some is added to biosolids and other composts.

See:

Wood Ash Program Benefits Farmers

WCAX-TV, Channel 3 in Burlington, VT aired a story about the agricultural use of wood ash from the Burlington Electric wood-fired electricity generator in the city’s Intervale area.   The plant produces 100 tons of wood ash per week, according to the report, and Resource Management, Inc. manages the testing, marketing, and distribution to area farms.  The story notes that the cost to a farmer of the potash supplied in wood ash is about ½ that of traditional chemical fertilizer potash. The story includes video and an interview with a farmer in Alburgh. 

Additional information on use of wood ash in agriculture:
Wisconsin
Southeastern U. S.
Alberta, Canada