Switchgrass

The knowledge that has been collected on switchgrass at world level, covering the whole production chain, is presented in this chapter. Although several breeding programs have been carried out in the United States, switchgrass is still considered primarily as an undomesticated plant with great potential for agronomic and biofuel trait improvements. There are a large number of available varieties (lowland and upland) covering latitudes from Mexico to the far north of North America. When switchgrass had been successfully established the celling yields could be anticipated as early as the second or third year, and its lifespan could be longer than 15years. In most studies, lowland varieties have been reported as more productive than upland varieties. Nitrogen fertilization should be avoided at the establishment year but should be applied from the second year and thereafter on an annual basis. Most studies agreed that the final harvest should be done a few weeks after a killing frost (winter). The harvested biomass is characterized by a high portion of leaf material (∼40%), while its moisture content may be quite low (∼20%). The lignocellulosic biomass of switchgrass is suitable for energy production through thermochemical (gasification, combustion, and pyrolysis) and biochemical (advanced biofuels: bioethanol and biogas) processes.