"Bioenergy Potential of the United States Constrained by Satellite Observations of Existing Productivity" Environmental Science & Technology

http://pubs.acs.org/doi/abs/10.1021/es203935d

"While EISA energy targets are theoretically achievable, we show that meeting these targets utilizing current technology would require either an 80% displacement of current crop harvest or the conversion of 60% of rangeland productivity. Accordingly, realistically constrained estimates of bioenergy potential are critical for effective incorporation of bioenergy into the national energy portfolio."