Date of this Version
RSC Energy and Environment Series No. 3, Energy Crops, Edited by Nigel G Halford and Angela Karp.
Switchgrass (Panicum virgatum L.) is a warm-season perennial grass that is native to North America that is being developed into a biomass energy crop. It has been used in pastures and for conservation purposes in the Great Plains and the Midwest, USA, for over 70 years.1 The research supporting its use as a pasture and conservation species was largely conducted by US Department of Agriculture (USDA) research programs, most notably the Agricultural Research Service (ARS) project located at the University of Nebraska-Lincoln and USDA Plant Materials Centers that are located throughout the United States. In this report, its development as a biomass energy crop will be emphasized.
Beginning in 1984, the US Department of Energy (DOE) via the Oak Ridge National Laboratory (ORNL) funded multiyear screening of about 34 herbaceous species in the main crop-producing areas of the USA for their suitability for biomass energy production.2 The screening took place at 31 different sites in seven states and was largely conducted by universities. Switchgrass was among the top 2 or 3 species in the majority of the trials.2 Based on these studies, switchgrass was selected as a model species in 1991 by DOE. In addition to its high yields, it also was a widely adapted native species and had significant conservation attributes. It could be propagated by seed, there was an existing seed industry, and it could be grown and harvested with available hay equipment. Because of the previous USDA work, there were adapted switchgrass cultivars available for most areas of the USA where the tests were held. Preliminary results indicated that it had the capability to fix significant amounts of soil carbon. From 1992 to 2002, DOE funded switchgrass production and breeding research via the Biofuels Feedstock Development Program that was managed by the ORNL.2,3 This work was conducted by several USA universities and by the USDA-ARS project at Lincoln, NE. The emphasis on switchgrass in the USA led to its evaluation in multitrials in Europe.4–6 In 2002, the comprehensive DOE Feedstock Development Program was discontinued although significant research progress had been made.3,7,8 When the program was terminated, DOE was placing considerable emphasis on using crop residues such as corn stover for biomass energy because of their assumed availability and projected low cost.