Jeremy,
Jeremy Bunag wrote:
I remember reading in a University of Illinois paper that they were researching switchgrass biofuels, being much more fruitful than corn ethanol especially considering the yield per acre.
One of the advantages of switchgrass is that it is
perennial. In other words, one does not plant it every year like corn. This has a good many implications that may not be immediately evident. One of them is that the
root mass has a tendency to increase year on year, so that even after the top growth is harvested, the
carbon sequestered in the
roots continues to be sequestered, whereas by contrast, the root mass of corn dies and begins to degrade, and (largely depending on the tillage practices) that carbon is returned to the air.
Switchgrass can also be grown with far fewer inputs, either from repeated passes of a
tractor for weeding, etc., or from chemical inputs, again as compared with corn.
And of course switchgrass can be made into biogas, and several studies show (with regard to biogas from switchgrass) what Sampson's study showed with regard to biogas from corn, vs. either as compared to ethanol, which is that energy yields are higher with biogas.
Nature almost always has a better idea. That is not to say we can't improve on nature, but we had better know very well how nature does it before we head off into the blue with some gee whiz "solution" that we thought up ourselves. I mention this because even switchgrass is not as productive as more diverse prairie ecosystems. See, for example, this mention:
http://www.physorg.com/news68305721.html The fact is that a more diverse ecosystem is always a more stable ecosystem, and that applies to the ecosystem in a digester and apparently as well to an ecosystem vs. monoculture of energy crops.
d.