The USDA (2005) reports soybean yield worldwide to be 2.2 tons/ha. With an
average oil extraction efficiency of 18%, the average oil yield per year would be
approximately 0.4 tons/ha. This converts into 454 L of oil per ha. Based on current
U.S. diesel consumption of 227 billion L/yr, this would require more than
500 million ha of land in soybeans or more than half the total U.S. planted with
just soybeans! All 71 billion tons of soybeans produced in the U.S. could only
supply 2.6% of total U.S. diesel consumption.).