Submitted to: Eastern Native Grass Symposium
Publication Type: Proceedings
Publication Acceptance Date: July 25, 2003
Publication Date: October 20, 2004
Citation: Sanderson, M.A., Adler, P.R., Skinner, R.H., Dell, C.J., Curran, B. 2004. Establishment, production, and management of switchgrass for biomass feedstock in the northeastern u.s.. Eastern Native Grass Symposium. 3:92-97. Interpretive Summary: The use of native warm-season forage grasses as an energy crop may provide an alternative cash crop for farmers. Switchgrass has received much attention as a model herbaceous energy crop for the U.S. Attributes of switchgrass desirable for bioenergy cropping include its demonstrated high productivity across many environments, suitability for marginal land, relatively low water and nutrient requirements, and positive environmental benefits. Currently, the costs of producing energy from switchgrass and other biomass feedstocks exceed the cost of fossil-fuel derived energy; however, the potential environmental benefits of bioenergy, however, may offset the higher costs. Environmental benefits include increased soil conservation and quality, reduced losses of soil nutrients, protecting riparian zones, recycling nutrients from sewage sludge and livestock manure, and sequestration of carbon in the soil. Switchgrass can be managed flexibly. It can be integrated easily into cropping systems and switchgrass could be used either as biomass feedstock or as forage for livestock. A critical constraint to switchgrass production in the northeast is reliable and economic establishment techniques. Suggested options for overcoming establishment constraints include mowing to control weeds, planting in April or early May, relying on natural stratification of dormant seed to enhance stands, and selecting appropriate preceding crops and sites.
Technical Abstract: Switchgrass (Panicum virgatum L.) has been identified as a model herbaceous energy crop for the U.S. Estimates indicate that approximately 8 million tons of biomass could be available from dedicated energy crops grown in the northeastern U.S. in the future if priced at $50 per dry ton delivered. The principal constraints to switchgrass production in the northeast are reliable and economic establishment techniques and efficient use of external nitrogen inputs. The economics of producing energy crops depend on biomass yield, conversion efficiency, and cost of fossil fuel. Higher costs of biofuels compared to fossil fuels may be offset by valuing environmental benefits such as reduced runoff and erosion and associated reduced losses of soil nutrients and organic matter; increased incorporation of soil C, and reduced use of agricultural chemicals. Use of warm-season perennial grasses may also mitigate increases in atmospheric CO2. A near zero net C exchange, depending on fertilizer and fossil fuel use results from using biomass-derived fuels instead of fossil fuels, but also includes potential net CO2 reduction by sequestration of C in soil organic matter. Biomass cropping systems may also be useful in recycling municipal sewage sludge and livestock manure and as a buffer strip for protecting riparian zones. New research on biofuels at the USDA-ARS Pasture Systems and Watershed Management Research Unit will focus on sustainable biofuels cropping systems