Abstract
Bermudagrass (Cynodon spp.) is a common perennial summer forage crop in the southeastern USA that could also be used for cellulosic ethanol. This study was conducted on two sites near Midville, GA to assess biomass yields, nutrient utilization, and cellulosic ethanol production from bermudagrass over 2 years (2010 and 2011). The crop was harvested either three times (June, midsummer, and fall), twice (midsummer and fall), or only once in the fall. The first harvest tended to yield the same amount of biomass regardless of season. In 2010, the three-cut system yielded the most biomass overall, while there was little difference in total yields between the three systems in 2011. The concentrations of N, P, and K in harvested biomass changed with age of the crop and harvest timing. Total N and K removal was greatest in the three-cut system, particularly in 2011. Biomass fiber properties were slightly affected by harvest timing, but these data did not show correlations with ethanol yield. Ethanol production was measured by subjecting biomass to dilute acid pretreatment and simultaneous saccharification and fermentation (SSF) at bench scale in the laboratory. Some variation in ethanol production was observed among treatments in 2011. Though harvest timing had minor effects on conversion of the biomass to ethanol, biomass yield is still the major factor that determines per hectare production of cellulosic ethanol from bermudagrass. Under the conditions in this study, a single harvest appears to be the most economical system for producing cellulosic ethanol from this crop. To maximize yield, two or three cuts should be possible, but much more N would be removed in the three-cut system, with little additional yield.
Highlights
Bermudagrass (Cynodon spp.) is an important forage crop in the southeast USA that could be used for production of cellulosic ethanol [3]
Hemicellulose concentration was approximated by subtracting acid detergent fiber (ADF) from Neutral detergent fiber (NDF), and cellulose concentration was approximated by subtracting Acid detergent lignin (ADL) from ADF [20]
More rainfall was received in 2010 than in 2011 (Fig. 1), which likely explains the year effect and year by location interaction effect that were observed for biomass yield (Tables 2 and 3)
Summary
Bermudagrass (Cynodon spp.) is an important forage crop in the southeast USA that could be used for production of cellulosic ethanol [3]. The yield potential of bermudagrass is not nearly as high as these other grasses, growers are already familiar with managing bermudagrass for forage production, and several million hectares of bermudagrass hayfields and pastures are already in place. Bermudagrass can be harvested several times during the summer, whereas most other high-yielding energy grasses, such as switchgrass (Panicum virgatum L.) and giant miscanthus (Miscanthus×giganteus Greef et Deuter), would likely be harvested in the fall or winter after senescence to maximize yield and nutrient efficiency [9, 14, 15]. Bermudagrass has the potential to fill a gap in the overall biomass harvesting season to allow for a more steady supply of biomass to the cellulosic ethanol refineries
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
