||Grasses provide quick carbon accumulation via photosynthesis, without tying up agricultural land for significant periods of time. The biomass produced from grass can be utilized as a biofuel, either through direct combustion or as a precursor to syn-gas. Utilities often fault the use of grass hay in generation facilities because of the high silica and potassium content. Species used in this study were assessed for yield, yield loss post-frost, ash content, and mineral components. The species were Miscanthus floridulus (giant maidengrass), Panicum virgatum (switchgrass), Pennisetum purpurea (elephantgrass), and Sorghum bicolor (sorghum sudangrass).
Plants were established by appropriate means and maintained to maximize yield. At the end of each growing season, subplots of the yield trial were cut, dried, and loosely bundled. Bundles were exposed to ambient conditions. At four-week intervals, from December to April, samples were taken for analysis. Yield data indicated that the three perennial species yielded approximately three times more than sorghum-sudangrass. Of the four species tested, elephantgrass yielded the greatest during the first year of the study, but plots suffered severe damage from single-digit temperatures during the intervening winter. Ash analysis indicated that elephantgrass and sorghum-sudangrass had the greatest total ash and the highest potassium concentrations. Yield losses during the first 30-day period ranged from 30 to 40% depending on species. Most of the yield loss was due to significant loss of leaf material. Of the four species
tested, switchgrass would be the best choice because of its relative ease of establishment coupled with its lower innate ash and potassium content.