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Dale, who also is associate director of the MSU
Office of Biobased Technologies, is one of seven speakers discussing
biofuels and biopower at a symposium, titled "Renewable Energy from
Biomass: Technology, Policy, and Sustainability," at the American
Association for the Advancement of Science annual meeting.
An internationally recognized expert on producing
ethanol from cellulose, Dale used a powerful agroecosystem model
called CENTURY and life cycle analysis to compare and analyze various
methods of producing corn for ethanol in 38 counties in eight states.
"Nitrous oxide was by far the dominant greenhouse
gas produced, almost all of it generated at the farm level," Dale
explained.
Making some modifications to the way corn is grown
- using cover crops, for example - can reduce the amount of greenhouse
gases released. Planting winter cover crops, such as rye grass,
reduces nitrous oxide emissions and boosts levels of organic matter in
the soil, which makes for more fertile soil.
Harvesting the corn stalks or the cover crop to
make cellulosic ethanol also reduces nitrous oxide emissions and
reduces overall greenhouse gas levels because the ethanol is used
instead of gasoline. But without proper management, harvesting corn
stalks also can reduce the amount of organic matter in the soil, which
reduces the fertility of the soil over time.
"We need to carefully consider and intelligently
manage the entire ethanol production system for long- term
sustainability – not just focus on pieces of the system," Dale said.
"Ethanol is and will be a critical part of reducing our national
dependence on oil for liquid fuels. Production technology for both
corn and cellulosic ethanol is advancing rapidly. So it's essential
that we understand how to improve all portions of the system for
maximum environmental benefits." |
