Environmental Engineering Reference
In-Depth Information
28
Shrub Willow
Lawrence B. Smart and Kimberly D. Cameron
Cornell University
contents
28.1 Introduction ........................................................................................................................ 687
28.2 Diversity and Ecology of Salix ........................................................................................... 688
28.3 Historical Cultivation of Willow ........................................................................................ 692
28.4 Cultivation of Shrub Willow for Biomass Production ........................................................ 694
28.5 Harvesting and Conversion of Willow Biomass ................................................................. 696
28.6 Pests and Diseases of Willow Bioenergy Crops ................................................................. 699
28.7 Genetic Improvement for Increased Yield and Resistance ................................................. 701
28.8 Future Commercialization of Willow Bioenergy Crops ..................................................... 702
References ...................................................................................................................................... 703
28.1 IntroductIon
On a global scale, issues surrounding diminishing fossil fuel supply, increasing demand for energy,
and strategic policies for national security, all in the context of rising atmospheric levels of carbon
dioxide (CO
2
) and increasing evidence of climate change, will contribute to rapid growth in the use
of renewable biomass as a source of energy, especially in the United States and Europe. Biomass
produced and aggregated in the agricultural and forestry industries can be used in three primary
energy sectors: to generate electricity, transportation fuels, or heat. Across multiple scales (state,
regional, national, and international), agreed-upon caps or legislated restrictions on carbon emissions
are driving up the cost of producing electricity from fossil fuels, especially coal, and are inspiring
a shift to the use of biomass to fuel the boilers in power plants. The U.S. Department of Energy and
the Biomass Research and Development Board have highlighted the unsustainable rise in demand
for foreign petroleum in the United States and have provided leadership in proposing a National
Biofuels Action Plan (http://www1.eere.energy.gov/biomass/pdfs/nbap.pdf) to meet a national goal
of replacing 15% of gasoline usage with biofuels and to increase biofuel production in the United
States to 35 billion gallons per year by 2017. To meet these goals in an environmentally sound
and sustainable manner, there will need to be dramatic increases in the total production of biofuel
feedstocks. There is great potential for the production, aggregation, and use of plant biomass other
than corn grain as a feedstock for the production of biofuels in the United States. The growth of
perennial woody crops as a feedstock crop for biofuels and bioproducts offers significant advantages
with respect to net energy ratio, soil conservation, nutrient management, biodiversity, and utilization
of marginal agricultural land, in addition to diversifying the feedstock commodities available to the
biofuels industry (Verwijst 2001; Volk et al. 2004b, 2006).
New York State is the largest user of heating oil in the United States. A vast majority of petroleum
used for heating in New York and throughout the Northeast United States is from foreign sources,
making the region dependent on economically volatile imports. The combustion of heating oil also
releases ancient carbon that contributes to global climate change. Renewable woody biomass holds
great potential as a feedstock for heat production because it has numerous environmental benefits
687
