There is a growing body of independent research reporting the results of practical field trials for corn stover harvesting, switchgrass production, and other sources of advanced and cellulosic biofuels. This research has led to guidelines and measurement tools for sustainably harvesting crop residues, in order to ensure soil health.
The main point of this decade-old area of research is to help farmers know their fields and to engage in sustainable harvesting practices. Companies planning to use corn stover for cellulosic biofuels have worked with local farmers under USDA guidance to ensure sustainable harvesting.
Farmers take this guidance seriously and know it to be unwise to engage in the corn stover harvesting practices recently modeled by University of Nebraska-Lincoln researchers. In a letter to the journal Nature Climate Change these researchers modeled the effects of harvesting excessive amounts – more than 75% – of corn stover for use in biofuels. The research was conducted under a reported $500,000 grant from the U.S. Department of Energy. As any researcher knows, bad inputs lead to worse outputs, so it is no surprise that this report comes out with a different conclusion from Purdue University (https://www.extension.purdue.edu/extmedia/EC/RE-3-W.pdf) and University of Minnesota (http://ageconsearch.umn.edu/bitstream/148851/2/Julie%20Manuscript%20final.pdf) studies that clearly demonstrate how advanced biofuels can help cut climate-changing carbon emissions.
BIO produced a report in 2006 on Achieving Sustainable Production of Agricultural Biomass, written by one of the pioneers in corn stover harvesting field trials. That study emphasized that each individual field should be evaluated before harvesting corn stover, since variations in soil carbon and moisture will impose site specific limits. That study also recommended use of cover crops and low-till field management for soil health.
The new study from the University of Nebraska provides a useful reminder that sustainable practices are necessary in producing any fuel. Sensationalized media headlines saying that cellulosic biofuels are worse than gasoline simply ignore the realities of today’s gasoline. Since the environmental impact of gasoline was last measured in 2005, the United States’ energy picture has changed completely. We now import more oil from Canada than from OPEC. And Canada’s oil comes from oil sand bitumen. So even using this resource efficiently can produce more environmental damage.