Because there is energy used in planting, fertilizing, herbicizing, harvesting, trucking, processing, distributing. With petroleum a few steps are eliminated since the 'finite fossil' fuel is trapped underground. (also energy content of final product)

I disagree with the study though ... as it doesn't take into count the other variables. For example the primary use of 'soybeans' is the 'meal' and the oil is the byproduct. The study only looks at the 'oil.' Also ... we all know that there is more cost involved in 'securing' crude oil (especially from the middleeast) than just pumping it out of the ground and processing ... what is that cost? An let's contemplate the environmental cost of petroleum vs. biofuels ... again no calculations. I'd rather spill some biodiesel or ethanol and pay for the clean up than a tanker full of crude oil along the shoreline ... besides the $$$ cost ... what about the environmental damage that is difficult to price?

--RichC --- "My Desultory Blog" & CinciTDI Club