Crop residue may be too valuable to harvest for biofuels

In the rush to develop renewable fuels from plants, converting crop residues into cellulosic ethanol would seem to be a slam dunk.

However, that might not be such a good idea for farmers growing crops without irrigation in regions receiving less than 25 inches of precipitation annually, says Ann Kennedy, a USDA-Agricultural Research Service soil scientist and adjunct professor of crop and soil sciences at Washington State University.