Switchgrass: a Valuable Biomass Crop for Energy

Abstract

Switchgrass (Panicum virgatum L.) is a warm-season (C4) perennial grass that is being developed internationally into a biomass energy crop. It is native to the prairies and steppes of North America. Switchgrass has been used in pastures and for conservation plantings in the Great Plains and the Midwest, USA, since the 1940s. The research supporting its use as a pasture and conservation species was initiated in the mid-1930s and was largely conducted by U.S. 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 which are located throughout the United States. It was often used in mixtures with other native warm-season grasses. Interest in switchgrass as a bioenergy crop began with potential biomass energy species screening trials conducted in the 1980s which were funded by the U.S. Department of Energy (DOE) via the Oak Ridge National Laboratory. Switchgrass was among the top two or three species for biomass yield in the majority of the trials. In 1991, switchgrass was selected as the model perennial grass biomass species by DOE. In addition to being a native species, other desirable attributes were its known soil conservation benefits, it could be propagated by seed, there was an existing seed industry, and it could be grown and harvested with available forage equipment. Since 1992, there has been a steadily increasing amount of research conducted on all aspects of switchgrass production and use as a biomass energy crop both in the USA and in Europe. This funding was largely by gov- ernment agencies until the early 2000s when commercial companies also began investing in switchgrass research. Over $1 billion has been allocated in the USA to biomass energy research since 2006 by both government and commercial com- panies with much of the emphasis on perennial grass energy crops such as switchgrass. Because of the investments that have been made in switchgrass research, a large amount of information has and is emerging from the switchgrass research pipeline and the pipeline itself is increasing in volume and delivery rate. This book is the first devoted entirely to switchgrass. International authorities on the development and use of switchgrass for bioenergy have reviewed and summarized by major topic areas all the past and current scientific literature on switchgrass. Information is provided about the evolution of switchgrass as an energy crop, its breeding, genetics, genomics, physiology, and management including harvest and storage. The book also provides information about the economics of switchgrass production for bioenergy and information about switchgrass biomass biochemical and thermochemical conversion into biofuels. In addition, the potential environmental impacts of switchgrass grown for bioen- ergy are reviewed. This book, Switchgrass: a Valuable Biomass Crop for Energy is very comprehensive and should prove to be an invaluable resource.