Comments

Clearly some of us aren't reading the article fully nor researching Dr. Tilman's work before attacking him. Firstly, to fiftycal, had you carefully read the article and had a better understanding of agricultural practices, you would understand how the >200% yield comes about. Growing corn requires several field operations, plowing, planting, fertilizing (which costs fuel AND uses fertalizers which come from fossil fuels) and watering throughout the season. Additionally, ethanol processing is very energy intense and requires quite a bit of input to get out your desired fuels. As such, the NET (that means output minus the input) energy yield for corn is very very weak. Now in the article, Tilman describes for you how perennial prairie grasses are only planted once (they are perennial, thus will grow back each year without any more planting) and require NO fertilizer, NO watering, and NO plowing of the field. Harvesting is simply carried out with traditional grass baling operations that are well established. These grasses can then be used in a 5% blend with coal in existing coal power systems (this has been done successfully) and the NET energy they supply in this manner IS >200% that obtained with corn. Mr. J. Sanchez's comments were also simply wrong (and obviously politically motivated). What Dr. Tilman spoke of WAS the net energy yield. He has also addressed every question Mr. Sanchez brought up in his article "Carbon-negative biofuels from low-input high-diversity grassland biomass" published in the peer-reviewed and internationally respected journal "Science" (v 314, n 5805, Dec 8, 2006, p 1598) with a sound scientific analysis. If we take the time to actually look into the background of these articles before flaming them, we could avoid these silly misconceptions.