Interest in the use of biomass for bioenergy and bioproducts has developed over the past few decades because of the multiple environmental and rural development benefits associated with their production and use. The cultivation of willow was revitalized in Sweden in the early 1970’s in response to the need for alternative sources of domestically produced energy following the energy crisis. In North America willow production was started again in upstate New York in the mid 1980’s. The focus was research on cultivation of willow biomass crops as locally produced, renewable feedstock for bioenergy and bioproducts. Since 2004, commercialization efforts have begun in New York State with the designation of Double A as the sole licensee for willow hybrid varieties by SUNY ESF and the SUNY Research Foundation. Several million cuttings have already been sold to wood burning power plants and interest is now being generated by coal burning power plants and combined heat and power projects.

Willow shrubs have several characteristics that make them ideal for short rotation woody crop systems including the potential for high biomass production in short time periods, ease of vegetative propagation from dormant cuttings, a broad genetic base and ease of breeding, and an ability to resprout after multiple harvests. Its ability to attain high production levels quickly relates to an ability to reach it annual growth quickly, its ability to tolerate high planting densities and it rapid growth after first year coppicing. Ease of propagation relates to the ability of willow to propagate from dormant shoots. This trait greatly simplifies and speeds up the breeding, screening and deployment process for improved genetic material. The wide range of genetic diversity within the willow genus and the limited amount of domestication of willow as a crop means there is a tremendous potential to increase yields of shrub willows through traditional breeding and hybridization. There are about 450 species of willow worldwide. Finally willow is well known for its vigorous coppicing ability and it has been used for centuries to manage willow for a wide range of applications. Short rotation wood crops like willow that are harvested on rotations of five years or less are typically managed using a coppice system. Willow biomass cropping systems are built around its coppicing ability.

The cultivation of the willow biomass crops occurs on agricultural or fallow land and combines the knowledge from the fields of forestry and agronomy.

The system currently being used is based on years of research and operational experience in Sweden, the United States, Canada, and the United Kingdom. It employs a double row configuration which facilitates the use of agricultural equipment. Site preparation is begun in the fall before or the spring in which the planting will occur. Willow biomass crops are typically harvested on a three-to four year cycle using modified agricultural equipment that cuts and chips the biomass in a single operation. The product can then be delivered directly to end users. Willow plants resprout vigorously after each harvest, so seven to ten harvests are possible fro a single planting. Nutrients are applied after each harvest. These nutrient additions are designed to replace the nutrients removed during harvest rather than trying to maximize production.

The major value of willow is in the efficient production of energy and in the process due to the closed carbon cycle of willow biomass production there is a dramatic limitation of greenhouse gas emissions. The high net ratio for willow biomass energy by direct fire or gasification ranges from 10 to 13 mega joules of electricity/megajoule of fossil fuel. Related to carbon dioxide production, there is a 95 percent reduction in greenhouse gas emissions relative to the current US grid.

Growers of biomass crops are required to sign license agreement. To download and print this agreement in PDF format, please click on the attachment below.

For further information or inquiries, please contact Dennis Rak