Switchgrass as a Dedicated Energy Crop

Switchgrass stand

The role of production agriculture is very important for the future of sustainable food and biorenewable energy production. The 2007 Energy Independent and Security Act mandates 36 billion gallons of biofuel production by 2022, with 21 billion gallons coming from advanced biofuels such as ethanol from cellulosic biomass feedstock. Twenty-one billion gallons of biofuel will require over 350 million tons of dry cellulosic feedstock annually. To meet the U.S. federal goal, a significant portion of biomass feedstock will come from production agriculture, including crop residues and dedicated perennial energy crops such as switchgrass (Panicum virgatum). In Illinois, growing perennial energy crops to provide biomass feedstock will play an important role in meeting this goal. Over 4 million of the 27 million arable acres in Illinois may be dedicated for these energy crops, including less-productive fields and some now enrolled in the Conservation Reserve Program (CRP). Switchgrass is a perennial, warm-season C4 grass native to the North America tallgrass prairie that has great potential for biomass production. Growing switchgrass on marginal and less productive soils as a renewable bioenergy crop will help producers maximize their land use as well as provide benefits to soil, water, and air quality.

Switchgrass biomass

Our research is being conducted to help future growers of perennial crops effectively manage their stands through nutrient and harvest management. One study of six switchgrass stands planted in 2009 at each of the University of Illinois research and education centers aims to determine the most effective fertility management and harvest time. Five fertility treatments (0, 50, 100, 150, and 200 lb nitrogen/acre with urea and slow-released urea) were applied along with three harvest treatments in summer, fall, and the following spring before emergence. All stands showed a positive response to fertilization rates. Yields were highest during the summer and decreased with each later harvest. Even though the summer harvest was the highest, research has shown that nitrogen content is higher in switchgrass biomass harvested at peak standing crop than when the crop is harvested after a killing frost and senescence. Delaying harvest until the end of the growing season or after a killing frost with a single-cut system significantly reduces the nitrogen requirement and maintains the switchgrass stand's health and longevity. A healthy stand will help prevent weed competition as well as allow for yields to remain consistent over time.

With the rising costs of energy and the demand for alternative energy sources, effectively choosing the right biomass feedstocks will allow for quick development of a sustainable energy source, which is vital to our national security and environmental quality. It is our goal to provide Illinois farmers with quality research to help develop a baseline for managing switchgrass as well as other future dedicated energy crops. The marketplace offers many choices when deciding on a biomass feedstock.We hope that our research into several of the native and nonnative grasses—big bluestem, prairie cordgrass, indiangrass, and Miscanthus x giganteus—will allow producers to tailor their bioenergy crop production to best suit their land and needs. Our success will be due in part to answering the concerns you have as growers and consumers.


Allen Parrish

Allen Parrish
Biomass Research Specialist
Department of Crop Sciences
217-333-7736
aparrish@illinois.edu

D.K. Lee

D.K. Lee
Assistant Professor of
Biomass and Bioenergy
217-333-7736
leedk@illinois.edu