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The Center for Native Grasslands Management

Title: Harvest Management of Switchgrass in Pennsylvania for Yield and Biofuel Quality
Year: 2005
Author(s): Adler, P. R., Sanderson, M. A., Boateng, A. A., Weimer, P. J.
Source Title: Proceedings of the 4th Eastern Native Grass Symposium
Source Type: Proceedings
pages: 87-95
Original Publication:  
Abstract: Harvest management of switchgrass grown for biofuel must consider not only biomass yield but also the fuel quality of the biomass. A three-year study was conducted to determine the effect of fall versus spring harvest on biomass yield and biofuel quality. In winters with low snowfall, delaying harvest from fall to spring did not affect yield. However, in winters with above-average snowfall, biomass losses were 40%. About 25% of the yield reduction during winter resulted from losses in tiller weight with reductions in leaves and the panicles; however, 75% of the yield reduction was due to biomass not picked up by the baler. Although the yield is highest in late summer, mineral element concentration in the biomass decreases after the peak yield through a killing frost and into spring, thereby enhancing biomass quality for combustion. Although the biomass yield decreased over the winter, energy yield from gasification did not decrease on a unit biomass basis, whereas ethanol production decreased about 25%. Switchgrass moisture content needs to be less than 15% for storage but averaged 34% in the fall versus 7% in the spring. Although there was substantial reduction in switchgrass yield with spring harvest, the biofuel quality of spring-harvested biomass was greater than fall biomass.
Publisher: The University of Kentucky Department of Forestry, Lexington, Kentucky
Editor(s): T. G. Barnes