Woodbury,
Peter. B (Cornell University, Crop and
Soil Sciences Department, Cornell
University, Ithaca, NY, 4853; Phone: 607- 255-1448; Email: pbw1@cornell.edu)
P. B.
Woodbury *, J. H. Cherney, J. Wightman, J. M. Duxbury, W.J. Cox, C. L. Mohler,
S. D. DeGloria
New York State has set goals of reducing greenhouse
gas emissions below 1990 levels by 5% in 2010 and 10% in 2020. We evaluated how
biomass fuel production could help to achieve these goals. The suitability of
lands throughout the state for increased biomass production was analyzed for
corn (Zea Mays L.), soybean (Glycine Max (L.) Merrill), switchgrass (Panicum
virgatum L.), reed canarygrass (Phalaris arundinaceaL.), unimproved grasslands,
and existing mixed-species forests. New York State has approximately 19.7
million acres of forestland (59% of total); 6.2 million acres of crop and hay
land (19%); 2.1 million acres of pasture and old-field land (6%); 1.5 million
acres of developed land (4%); 1.2 million acres of wetlands (4%), and 2.2
million acres of water (7%). Of current pasture, old field, and hay land, we
estimate that 1.5 million acres may be currently underutilized and potentially
available for herbaceous biomass crops without reducing current row crop, corn
silage, or hay silage production that is important for New York’s dairy
industry.
For corn, soybean, switchgrass, reed canarygrass and unimproved grasslands, we
predicted the suitable area and production potential for each soil type in the
state. These predictions were linked within a geographical information system
to spatially referenced soils data (STATSGO). Potential yields and areas under
good management on underutilized land were estimated to be: corn 110 bu/ac (on 1.3
million acres) , soybean 37 bu/ac (1 million acres), reed canarygrass 4.1 t/ac
(1.5 million acres), switchgrass 3.5 t/ac (1.2 million acres), and unimproved
grasslands 1.9 t/ac (1.2 million acres). These crops would use the same land
base, and so are mutually exclusive strategies.
Based on inventory data from the USDA Forest Service, there are approximately
15.4 million acres of forestland that have adequate growth rates for commercial
timber production and that are not reserved for non-timber uses such as parks.
Of this timberland, 10 million acres are in mixed hardwood species and are
privately owned, not including forest industry land. We assume that half of
this land (5 million acres) is potentially available for additional biomass
production. Predicted potential additional yields based on current growth rates
of existing forests, excluding current harvests and mortality, were estimated
to average 0.5 tons/acre/year. Predicted yields using residues from timber
stand improvement cuts are estimated to be 0.8 tons/acre/year. For maximal
greenhouse gas mitigation potential, the best agricultural strategy is
producing reed canary grass for heat and the best forest strategy is timber
stand improvement cuts. Together, these strategies could reduce total New York
State emissions by 3.7%. These options provide 30-fold greater greenhouse gas
mitigation potential than corn for ethanol and 24-fold greater potential than
soybean for bio-diesel. For forests, it should be noted that greater wood
yields are possible with plantations, but we have not yet evaluated plantation
strategies. Further analysis is required to determine the degree to which these
biomass production options are feasible under economic and social constraints.
We have examined biophysical and some economic constraints to increased
production, but have not examined infrastructure constraints such as road
access, and ability of existing power plants to use biomass. Furthermore,
not all land owners are willing or able to increase biomass production, and if
they do so, not all will achieve optimal production. Therefore our estimates of
potential production could be too optimistic, but they do suggest that further
development of biomass strategies for mitigating greenhouse gas emissions is
warranted in New York State and other similar regions.