Shrub willows are a promising source of woody biomass. They can provide an effective vegetative cover that will help reduce water runoff and protect the banks of streams and lakes. In addition, they produce a renewable energy resource when harvested and can be used as a biofuel to generate power.
The SUNY ESF’s willow biomass crops have been a successful program since 1986. This crop is a perennial shrub and can be grown on marginal farm land. After three years of growth, the crop can be harvested. The USDA Biomass Crop Assistance Program pays farmers up to 75 percent of the establishment costs of willows. Farmers will also receive technical advice and supervision from experts.
Researchers at the SUNY ESF are studying willows as an alternative energy source. As part of this effort, a 34-acre demonstration plot was planted in 2006. The willows were harvested after two years. Willow cuttings were then used to form living willow hedges. These structures have been designed by Judy Drew and Nicol Browne.
For its bioenergy applications, willow is a relatively low-energy tree, with the yield of a hectare of plants requiring only 0.092 MJ of non-renewable energy. Harvesting technology requires transport, so researchers are looking for ways to improve the collection system. Currently, willow is being used for windbreaks, slope stabilization, and shelterbelts.
Several varieties of willow are known to be beneficial to the environment. Some species of willow are less susceptible to pests and disease epidemics. Another benefit of willow is its ability to retain nutrients in the soil. There are hundreds of species of willows that can be used in many ways. Several species are suitable for use as a plantation for bioenergy.
To produce a biomass crop, willows require only a third of the nitrogen fertilizer needed for corn. Unlike corn, willows can tolerate poor quality soils. Additionally, willows are able to survive in wet fields. However, this may not be an ideal situation for some farmers.
When willows are planted, the soil needs to be prepared. This includes cultivating, tilling, and disking. A weed barrier is then placed on top of the planting site. Planting should be done in full sun and ideally without competing with food crops.
During the growing phase of willow, the roots of the tree are very aggressive, seeking moisture. If they are near a drainage area, they can become a problem. Using slat mowers, the roots can be cut off at the right time. Alternatively, forestry harvesters can solve this problem.
The harvesting process can be time consuming. Researchers at the SUNY ESF are looking for a better way to collect the willows. Their goal is to develop a complete system for willow biomass production on a commercial scale. Having a better transportation system can ensure a successful and efficient production.
The USDA has a Biomass Crop Assistance Program to help renewable energy companies manage risk. Qualified farmers will be provided with funding to help them plant willow and a guaranteed buyer when the crop matures.