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Vertical distribution of structural components in corn stover

Author:
Johnson, Jane M. F., Karlen, Douglas L., Gresham, Garold L., Cantrell, Keri B., Archer, David W., Wienhold, Brian J., Varvel, Gary E., Laird, David A., Baker, John, Ochsner, Tyson E., Novak, Jeff M., Halvorson, Ardell D., Arriaga, Francisco, Lightle, David T., Hoover, Amber, Emerson, Rachel, Barbour, Nancy W.
Source:
Agriculture 2014 v.4 no.4 pp. 274-287
ISSN:
2077-0472
Subject:
Zea mays, alkalinity, biomass, chemical composition, corn, corn stover, cutting, ethanol, fuel production, gasification, glucans, harvest date, heat, height, leaves, lignin, maturity stage, stems, sugars, xylan, United States
Abstract:
In the United States, corn (Zea mays L.) stover has been targeted for second generation fuel production and other bio-products. Our objective was to characterize sugar and structural composition as a function of vertical distribution of corn stover (leaves and stalk) that was sampled at physiological maturity and about three weeks later from multiple USA locations. A small subset of samples was assessed for thermochemical composition. Concentrations of lignin, glucan, and xylan were about 10% greater at grain harvest than at physiological maturity, but harvestable biomass was about 25% less due to stalk breakage. Gross heating density above the ear averaged 16.3 ± 0.40 MJ kg−1, but with an alkalinity measure of 0.83 g MJ−1, slagging is likely to occur during gasification. Assuming a stover harvest height of 10 cm, the estimated ethanol yield would be >2500 L ha−1, but it would be only 1000 L ha−1 if stover harvest was restricted to the material from above the primary ear. Vertical composition of corn stover is relatively uniform; thus, decision on cutting height may be driven by agronomic, economic and environmental considerations.