I feel the WRONG question, leading to the WRONG assumption has been left on our doorstep.
We can have Ethanol production and quality food while building top soil and sequestering CO2 in the process.
The Problem is not one of having enough fertilizer and land area to have food and fuel. You have been tricked into believing that the equation involves an inescapable Either-Or equation. I got news for you. The WRONG assumptions are being left for you to chew on.
Consider the problem with the above limitations is Monoculture.
You can have more food production and sequester CO2 in the soil using Permaculture, ending up with more food and more people involved in agriculture and small business in a healthy way.
The inputs needed to grow great food, and have by products like Ethanol are not an either-or proposition.
Check out http://permaculture.com/
Other answers exist at Acres USA
Check out "Alcohol Can Be a Gas" by David Blume. In time, copies will be available at http://ush2.com/ when supplies are replenished.
You can listen to David Blume on my server at http://network76.com/
You will need a great media player like Xmms, VLC, or Winamp. WMP just won't cut it.