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ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Cell Wall Biology and Utilization Research » Research » Publications at this Location » Publication #309417
Title: The effects of hybrid relative maturity on corn stover for ethanol production and biomass composition

Author
item WILKENS, STEVEN - University Of Wisconsin
item Weimer, Paul
item LAUER, JOSEPH - University Of Wisconsin

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/12/2015
Publication Date: 9/4/2015
Publication URL: http://handle.nal.usda.gov/10113/62003
Citation: Wilkens, S., Weimer, P.J., Lauer, J.G. 2015. The effects of hybrid relative maturity on corn stover for ethanol production and biomass composition. Agronomy Journal. 107(6):2303-2311.

Interpretive Summary: Corn is the largest grain crop in the U.S., and corn stover represents the most abundant and easily collected biomass residue material for potential conversion to ethanol. Although an enormous number of hybrid varieties with different rates of maturity are available, there is little information on how well the stover from these varieties may be converted to ethanol on a per acre basis. In this study, we showed that the compositional differences among different hybrids, in terms of the suitability of their stover to generate ethanol in an enzyme/yeast conversion process, are minor. However, because the yield of stover is highly dependent on the relative maturity of the different hybrids (with yield increasing as days to maturity increases), the main factor of total ethanol yield was stover yield. Increasing ethanol yields will likely occur by increasing stover yields and not by stover composition. Therefore, until premiums for stover composition are made available to farmers for ethanol production, the adoption of full-season or longer-maturing hybrids should be implemented for increased stover and ethanol yields.

Technical Abstract: Full-season corn (Zea mays L.) hybrids take advantage of more of the growing season than shorter-season hybrids, often leading to greater grain and biomass yield. Many agronomic experiments aimed at corn stover production have been performed at forage harvest rather than later when stover is normally harvested for biofuel measurements. The objective of this research was to evaluate the influence of hybrid relative maturity (RM) on stover ethanol production, ruminant digestibility, and biomass composition. Hybrids selected were high-yielding commercial grain hybrids grown throughout Wisconsin and ranged from 85- to 115-d RM in 10-d RM increments in 2009, and in 5-d RM increments in 2010. Hybrids were harvested at physiological maturity or after a killing frost. Stover and theoretical ethanol yields increased as RM increased at a linear rate of 0.210 Mg ha-1 and 67.1 L ha-1. Stover nutritional and biomass composition increased as RM increased; however, when compared to yield measurements, the range in biofuel production was minimal. Increasing ethanol yields will likely occur by increasing stover yields and not stover composition. Therefore, until premiums for stover composition are made available to farmers for ethanol production, the adoption of full-season or longer-maturing hybrids should be implemented for increased stover and ethanol yields.