<<

ATTRA Switchgrass as a Bioenergy Crop A Publication of ATTRA - National Sustainable Agriculture Information Service • 1-800-346-9140 • www.attra.ncat.org

By Lee Rinehart Switchgrass is a native warm-season, perennial grass indigenous to the Central and North American NCAT Agriculture tall-grass prairie into Canada. The plant is an immense producer that can reach heights of 10 Specialist feet or more. Its high cellulosic content makes switchgrass a candidate for production as well © 2006 NCAT as a combustion fuel source for power production. This publication discusses agricultural production aspects of switchgrass. Varieties, seed sources, crop establishment, management, and harvesting issues are presented. Ecological considerations are also discussed and a case study is presented along with references and further resources.

Contents Introduction ...... 1 Description, Range, and Adaptation ...... 2 Switchgrass Ecotypes and Varieties ...... 2 Establishment, Manage- ment, and Harvest ...... 3 Ecological Consider- ations: Prairies and Farmscapes ...... 6 Feedstock Quality ...... 7 Economics and Multiple Uses of Switchgrass ...... 7 Other Cellulosic Feedstocks ...... 9 References and Resources ...... 9

Photo courtesy of USDA NRCS.

Introduction stored in plant tissue. are renew- able in that plants grow back after harvest, This publication details the production and can be regenerative when sustainable of switchgrass for use as a cellulose-to- methods are employed to manage, harvest, ethanol and direct-combustion feedstock, and process the crops. Ethanol, used in ATTRA—National Sustainable and focuses on the agronomic and eco- (spark-plug) engines, is produced Agriculture Information Service through the fermentation of plant sugars is managed by the National Cen- logic considerations of switchgrass produc- ter for Appropriate Technology tion. Ethanol production is addressed in and of the mash to produce fuel (NCAT) and is funded under a alcohol. Ethanol can be produced from grant from the United States detail in the ATTRA publication Ethanol Department of Agriculture’s crops such as corn and sugarcane, which Rural Business-Cooperative Ser- Opportunities and Questions. vice. Visit the NCAT Web site are high in the sugars needed for fermen- (www.ncat.org/agri. Biofuels are carbon-based energy sources tation, or from cellulosic materials, such as html) for more informa- tion on our sustainable taken ultimately from solar energy as it wood by-products and high-fi ber grasses, agriculture projects. /$"5 is captured through photosynthesis and such as switchgrass. Switchgrass can also be directly com- (sunfl owers, gayfeather, prairieclover, prairie busted or co-fi red with to lower emis- conefl ower). These widely adapted species sions associated with the burning of that once occupied millions of acres of tall-grass fuel. However, for switchgrass to become prairie. Now they are rarely seen, usually practical as a directly combusted fuel on land that cannot be utilized for annual in coal plants, retrofitting current boil- cropping. Look for native plants like these in ers from coal or co-fired applications is protected areas along fencelines, in riparian required. For more information on this buffers, and especially in old cemeteries and aspect of switchgrass, see the Chariton church yards across the prairie states. Valley Biomass Project case study below. Switchgrass grows well in fi ne to coarse tex- Related ATTRA Switchgrass can be used as a fuel source tured soils, and in regions where annual pre- Publications to power ethanol plants, which results in cipitation falls between 15 and 30 inches or Alternative reduced use of fossil fuels and contributes more per year. It is an immense biomass pro- Agronomic Crops to a more positive energy balance for cellu- ducer, and can reach heights of 10 feet or losic ethanol. more in wetter areas of the country. In gen- Alternative Soil eral, ecotypical differences are related to local Amendments Although recent news has been full of excit- soil and climatic characteristics, with eastern Biodiesel—A Primer ing reports about ethanol and switchgrass, and southern varieties adapted to higher mois- producers need to be aware that a market for Biodiesel: ture conditions, and western and northern switchgrass as an energy crop is (in 2006) varieties adapted to drier conditions. The scarce to nonexistent. There is intense spec- Dimensions ulation about how, when, and whether these Converting Cropland potential markets will materialize. In the Switchgrass Ecotypes to Perennial Grassland meantime, corn ethanol is becoming more and Varieties Ethanol Opportunities popular in the marketplace. In fact, 14 per- As switchgrass evolved across North Amer- and Questions cent of the 2005 U.S. corn crop was used ica, different ecotypes emerged with genetic Nutrient Cycling to produce ethanol, and the percentage is and morphological characteristics that pro- in Pastures expected to grow. produc- vide a good “fi t” to a particular place. Thus tion is, from a processing and distribution ecotypes in the south typify southern char- standpoint, still in a research and develop- acteristics, such as long season growth and ment phase. As further research into cel- subsequent high dry matter yield, given lulosic ethanol production and process- favorable growing conditions. ing is completed, perhaps switchgrass can Two major types have emerged through nat- become a cost-effective, viable alternative ural selection. The upland types favor drier energy source. soils and fare better in semi-arid climates. The lowland varieties grow better in heavier Description, Range, soils and are found where water availability and Adaptation is more reliable. The lowland cultivars have the genetic ability to produce more dry mat- Switchgrass ( L.) is ter than the upland cultivars. a native warm-season, perennial grass indigenous to the Central and North Plant breeders at various Agriculture American tall-grass prairie. It is found Research Stations from Texas to Nebraska into Canada and ecotypes have been have collected seeds from local switchgrass identifi ed in regions from the Atlan- colonies and reproduced them into rela- tic coast to the eastern Rocky Moun- tively uniform strains adapted to particu- tain front. Switchgrass is historically lar locales. These strains, once some bit found in association with several other of uniformity is achieved through artifi cial important native tall-grass prairie selection, are then registered as cultivars plants such as big bluestem, indian- or varieties. This simple breeding program Illustration courtesy of OSU grass, little bluestem, sideoats grama, has created the many switchgrass varieties Forage Information System. eastern gamagrass, and various forbs available today. Page 2 ATTRA Switchgrass as a Bioenergy Crop Upland Varieties Developed by USDA-ARS and Nebraska Agricultural Research Division, Dept. of Agronomy, Univ. of Nebraska. Trailblazer Released 1984. Collections from natural grasslands in Nebraska and Kansas. Adapted to Central Great Plains and adjacent Midwestern states. Developed by Plant Materials Center, NRCS, Manhattan, Kansas. Released 1944. Upland-type switchgrass. Widely Blackwell adapted to Kansas, Oklahoma, southern Nebraska, and northern Texas in areas with 20 inches or more of annual precipitation. Plant Materials Center, NRCS in cooperation with the Missouri AES. Released 1973. Tolerant to fl ooding. Adapted Cave-in-Rock to Midwest. Pathfi nder Selected at Nebraska AES, Lincoln, ARS cooperating. Released 1967. Winter-hardy, late maturing. Selected at Oklahoma AES, Stillwater, ARS cooperating. Released 1955. Forage yield under outstanding Caddo for native grass; recovers well after mowing. Lowland Varieties Developed by Texas Agricultural Experiment Station and NRCS, Knox City, Texas. Released 1978. A premier Alamo lowland variety, heavy yields especially in the south. Developed at Kansas AES and ARS, Manhattan. Released 1963. Developed for soil conservation in poorly drained Kanlow or frequently fl ooded sites. Source: Oregon State University, 2006.

Research studies have determined that select- local Natural Resources Conservation Ser- ing varieties based on location increases the vice (formerly SCS) or Cooperative Extension survivability and productivity of a switch- offi ce for varieties adapted to your area. grass stand. Parrish and Fike (2005) have found a “strong correlation between latitude Establishment, Management, of origin and yield,” and “the main factor determining adaptation of a cultivar was its and Harvest latitude of origin, with southern cultivars Switchgrass has been successfully estab- having higher yield potentials as they are lished by several well-known methods: moved north.” • conventional tillage and drill planting, Switchgrass varieties should therefore be • no-till planting into crop stubble or chosen based upon ecotype (whether an pasture, including CRP, and upland or lowland variety) and the lati- tude of origin. For instance, a high-yield- • frost seeding. ing southern lowland variety like Alamo can For successful biomass plantings, plant 4 to potentially outproduce upland varieties in 10 pounds of switchgrass seed per acre at more northern latitudes. Check with your a depth of ¼ to ½ inch to obtain a plant

Seed Sources Oregon State University’s Forage Information System has seed source information on the varieties listed here and more. Some OSU variety fact sheets include seed source links to companies selling seed. See http://forages.oregonstate.edu/main. cfm?PageID=172&SpecID=26 to access the Switchgrass fact sheet and seed sources. You can also call your local Natural Resources Conservation Service or Cooperative Extension offi ce to request recommenda- tions of seed dealers in your area. NRCS and Extension phone numbers can be obtained in the Federal and County governments sections, respectively, of your local telephone directory. Also, you can access local NRCS and Extension directories on the following websites: Natural Resources Conservation Service – http://offi ces.sc.egov.usda.gov/locator/app?agency=nrcs Cooperative Extension Service – www.csrees.usda.gov/Extension/index.html www.attra.ncat.org ATTRA Page 3 a warmed soil with non-dormant seed. Switchgrass seedlings can compete better in warmer soils when on even footing with warm-season weeds. A producer should expect slow switchgrass establishment even with non-dormant seed and good planting management. As with most native perennial grasses, switchgrass becomes fully productive only upon the third year after planting. Seed Dormancy. Switchgrass seeds can be very dormant right out of the bag. A method to break dormancy ensures higher rates of germination. Without a dormancy-breaking step in the planting process, as few as fi ve Photo courtesy of USDA NRCS. percent of the seeds may germinate. This is density of greater than two plants per square thought to be one reason so many switch- foot. If drilled in rows, research suggests grass and other native warm-season plant- that wider spacings result in higher yields. ings fail. To break dormancy, seeds can be Row widths as wide as 32 inches have wetted and held at 41 to 50 degrees F for been successful in establishing productive one month, then carefully re-dried. This switchgrass stands. process is called stratifi cation and is useful for small amounts of seeds. There is risk of Switchgrass can be no-till drilled into crop causing heat damage to the seeds during stubble or grass sod during the winter drying, or causing premature germination when the grass is dormant. Drills should of seeds, so small amounts should be used be equipped with rollers or press-wheels to until you become familiar with the method. ensure adequate seed to soil contact. For germination and seedling survival, the soil Another dormancy-breaking method is to should remain moist for at least one month plant seed with a drill or no-till drill in win- to prevent desiccation and stand failure. ter or early spring. The cold temperatures the seed will experience will stratify them Frost seeding is the practice of broadcasting and help to break dormancy. Stratifi cation seeds during the early spring freeze-thaw can also be accomplished by frost-seeding period. The action of the soil freezing and in January to March. Again, care should be thawing throughout the day works the seed taken when planting switchgrass into cool into the soil, establishing seed to soil con- soils due to cool-season weed pressure. tact. Seed stratifi cation is effectively accom- plished with this method. Competition from “After-ripening” is the dormancy-breaking existing perennial grasses can be severe in practice of storing seeds in a warm envi- frost-seeded stands. Frost seeding without ronment for several years. When combined burn-down herbicides might work better in with no-till planting into a warm soil, it is fi elds with some bare soil and little competi- one of the most effective methods for estab- tion from aggressive perennials. lishing weed-resistant switchgrass stands. A word of caution. Planting switchgrass Weed Control. The establishment of warm- into cool soils can be problematic from season grasses is diffi cult not only because a weed standpoint. Cool season weeds of seed dormancy, but also because of com- germinate fi rst and can choke out switch- petition from weeds. Perennial forbs and grass seedlings when the soil warms. If warm-season grasses such as crabgrass ger- cool season weeds are a concern, con- minate in cooler soils and can have a severe sider no-till planting the switchgrass into impact on switchgrass stand establishment. Page 4 ATTRA Switchgrass as a Bioenergy Crop Switchgrass establishment can be improved end of the growing season as a nutrient-con- by utilizing cultural and mechanical con- serving strategy. Prairie systems will gain trol measures to reduce weed pressure. For nitrogen from the atmosphere at a rate of 2 instance, annual cropping with small grains to 10 pounds per acre per year. In addition, and fi eld peas for one or two years will pro- there is a reserve of nitrogen in the soil that vide an opportunity to control weeds sev- can be mineralized and made available for eral times during the season while building plant growth. The addition of this nitro- soil organic matter. Also, nurse crops can gen is a result of root death, leaf and stem sometimes reduce weed pressure and pro- death, and nutrient cycling from the urine vide a cash crop in the form of hay, silage, and feces of grazing animals. Nitrogen-fi x- or grain. Weeds can also be controlled in ing legumes can also contribute to nitro- newly planted switchgrass stands by mow- gen availability in the range of 50 to 150 ing two or three times during the growing pounds per acre per year, depending on the season. Mow the weeds down to the tops of species and percent composition of legumes the switchgrass plants so as to reduce the in the fi eld. impact of defoliation on the grass. Mowing Switchgrass for biomass should be har- can be effective against annual weeds espe- vested once per year, in the winter. Under cially as they mature but prior to seed set. witchgrass good management, a producer can expect Mowing can also reduce perennial weeds for biomass a yield of 1 to 16 tons per acre. According by effectively depleting root reserves by to the Agricultural Research Service, yields should be har- successive mowings when the plant is at the S in the Southeastern U.S. range from 7 to 16 vested once per year boot stage. tons per acre, and from 5 to 6 tons per acre in the winter. Fertility. Most research on switchgrass in the western Corn Belt, while yields in the fertility has focused on its use as a forage. northern plains are typically more modest Grazing livestock require protein, and higher at 1 to 4 tons per acre (Comis, 2006). If nitrogen (N) applications can ensure not only the protein composition at harvest is 2 per- high yields but better quality feed. Some cent, and assuming a yield of 6 tons per researchers have therefore considered nitro- acre, approximately 38 pounds of nitrogen gen fertilizer recommendations for switch- are harvested per acre. This nitrogen must grass to be much higher than necessary for somehow be replaced or recycled to main- biomass (i.e. cellulose) production. tain productivity. Switchgrass, as a native perennial grass of the Nitrogen can be added into the switch- North American tall-grass prairie, evolved in grass agroecosystem by (1) maintaining symbiosis with many other ecological fac- a legume component of at least 30 per- tors, including grazing, fi re, nitrogen-fi xing cent in the stand; (2) adding 2 to 3 tons of legumes and other forbs, and soil microor- manure per acre broadcast after harvest; ganisms including bacteria and fungi. Many (3) incorporating manure in the fall prior scientists now believe that soil microbes play to planting; or (4) using synthetic fertiliz- a major role in nutrient uptake. For exam- ers judiciously. Incorporating legumes into ple, micro-fungi (mycorrhizae) are thought to a switchgrass stand can be problematic play an important role in phosphorus uptake. from an ethanol feedstock quality perspec- These microbes are a natural constituent in tive, but not necessarily so if the biomass native grassland soils. is dried and used in direct combustion. If synthetics are used, the producer should A review of the literature suggests that remember that low rates will provide excel- switchgrass can be grown on soils of moder- lent biomass yields. Yearly applications of ate fertility without fertilizing, or with lim- no more that 50 pounds per acre should ited additions of fertilizer, and still main- be appropriate. tain productivity (Parrish and Fike, 2005). Nitrogen and carbon naturally cycle from It is very important to remember, though, shoots to below-ground parts (roots) at the that switchgrass has a remarkable ability to www.attra.ncat.org ATTRA Page 5 extract nitrogen from unfertilized soils. Par- or when growth is still low enough to permit rish and Fike (2005) report a study where a drill and packer wheels without damaging a fi eld was harvested for seven years with the crop. no fertilizer applications, and averaged 53 Harvesting. Switchgrass should be har- pounds of N removed per year with one vested with conventional haying equipment harvest per year. Clearly switchgrass, a after the top growth has completely died native prairie grass, has the genetic ability back. This will occur from mid- to late Octo- to survive and produce with minimal if not ber in most regions. Several studies have zero inputs. found that a single harvest of switchgrass Companion Crops. Some farmers use from late fall or early winter results in the companion or “nurse crops” in establishing highest sustainable biomass yields and good perennial crops such as alfalfa and grass stand persistence from year to year (Par- pastures and hayfi elds. An ideal nurse crop rish and Fike, 2005). Moisture should be will grow more quickly than the crop it 15 percent or less to facilitate quick baling accompanies and will provide plant cover and transport, and to ensure a higher qual- for the soil. Nurse crops must be removed ity feedstock. Switchgrass that is co-fi red in early enough to allow the protected crop to coal plants is burned at a moisture percent- grow unhindered. Nurse crops are often age of 12 to 13 percent. Contact the pro- used on slopes to prevent water erosion and cessing plant to determine the size of bale on level ground to prevent wind erosion they will accept. Many research programs and seedling desiccation. A nurse crop that have utilized large rectangular bales (3 x has been used successfully in establishing 4 x 8 feet) with some success, as these are switchgrass is sorghum-sudangrass. Sor- easier to transport than small squares. Be ghum-sudangrass is a warm-season annual sure to leave about a 6-inch stubble after grass that is used for grazing, hay, or silage. harvest. Forage research has shown that It is fast-growing in warm regions, broad- leaving stubble helps to trap snow, thereby leaved, and of excellent forage quality when protecting the root crowns from winter kill. harvested at the right time, which is just around panicle emergence. Other compan- Ecological Considerations: ion crops to consider would be corn, spring planted wheat, triticale, or annual ryegrass. Prairies and Farmscapes These crops could be planted early in the Switchgrass, formerly a natural part of the spring, followed by seeding of switchgrass prairie ecology of North America, may con- between the rows. Plant switchgrass into tribute to more stable agricultural systems. companion crops prior to crop emergence This assumes that switchgrass fi elds are inherently stable, benefi cial to wildlife, and suffi ciently productive to offer incentives to farmers to cultivate it. Switchgrass is deep- rooted, very effi cient at using nitrogen, and is thought to maintain a symbiotic or benefi - cial relationship with microscopic soil fungi, which make soil nutrients available to the extensive switchgrass root system. Switch- grass is an excellent plant to use in riparian buffer strips or on other sensitive lands, as its root system prevents erosion while slow- ing the travel of surface water, decreasing run-off from agricultural fi elds, and allow- ing for greater water infi ltration. Annual cropping, such as is done with corn, Photo courtesy of USDA NRCS. soybeans, and small grains, results in loss Page 6 ATTRA Switchgrass as a Bioenergy Crop of soil organic matter and release of soil carbon, whereas perennial crops can build Prairie Polycultures for Feedstock? soil organic matter and are thought to store Switchgrass has been studied as a monoculture for the production of eth- more soil carbon due to the large amount anol feedstock. One area that could possibly be studied by agronomists of underground biomass they produce and and agricultural engineers is the use of diverse prairie polycultures for maintain throughout the year. biofuel production and their eff ect on ethanol feedstock quality. Another area to investigate would be the effi ciency of polyculture feedstocks as a Switchgrass is generally planted as a direct combustion fuel for energy generation, which could be especially monoculture (a fi eld planted to only one useful for enhancing the sustainability of cellulosic ethanol plants. species, such as corn, alfalfa, or soy- beans), either as a forage crop or a feed- stock. Yield data have been developed by switchgrass stand can have an effective studying monoculture stands, and pure lifespan of well over 15 years, it might stands are thought to yield the highest fi nd a place in long rotations to build soil quality feedstock for biofuels production and renovate infertile farmlands. (see Feedstock Quality section below). Monocultural production is thought to be Feedstock Quality problematic by many farmers and advo- Producers who are experienced at growing cates of a more sustainable agriculture. grasses for livestock forage will fi nd that Monocultures are generally not as resilient producing switchgrass as an ethanol feed- as polycultures, or fi elds planted to more stock necessitates a management regime than one species. Diverse plants occupy unlike that utilized to produce quality for- more niches and better use soil and water ages. High-quality ethanol feedstock is low resources both above and below the soil in nitrogen content and high in cellulose. surface. Biodiversity also provides food Cellulose is broken down either by an acid and cover for numerous benefi cial organ- or into fermentable sugars prior isms, from microbes to earthworms, to to fermentation. Nitrogen reduces the con- insects and small mammals. A diverse version effi ciency of fuels into energy and agricultural system mimics the complexity can become an air pollutant after combus- of nature, and fosters an ecological bal- tion. Therefore, zero or low fertilizer nitro- ance that some farmers have come to rely gen applications and a single yearly harvest on to lessen the severity of pest problems after the plants have died back fully in the as well as build soil fertility by allowing winter produce the best feedstock, as well for natural nutrient cycling to occur. as the highest amount of above-ground bio- The natural, native tall-grass prairie of mass, for ethanol production. North America was not, of course, a mono- culture. Many grasses, legumes, forbs, Economics and Multiple Uses and shrubs contributed to this complex and stable plant and animal community. of Switchgrass This is important to remember, because The most important economic consider- a monoculture of switchgrass will never ations in the production of switchgrass are promise the same ecological benefi ts as (1) yield, (2) land costs, and (3) the prices a naturally diverse prairie. That being of other feedstocks for biofuel production. said, pure switchgrass stands still have Maintaining high yields and keeping costs signifi cant benefi ts, especially for fi elds low result in the best economic returns that have been cropped annually and are in recent switchgrass research projects. experiencing degradation due to erosion Another way to reduce costs and increase and depleted soil organic matter. A peren- productivity is to consider multiple nial grass stand offers nesting for birds, uses such as grazing and biomass produc- helps to sequester soil carbon, builds tion. Switchgrass is nutritious if grazed soil organic matter, and increases the prior to the boot stage of development, efficiency of the water cycle. Since a and is used as a livestock forage by some www.attra.ncat.org ATTRA Page 7 Case Study: The Chariton Valley Biomass Project The Chariton Valley Biomass Project is a Chariton Valley RC&D managed project that is funded by the US Department of Energy, the US Department of Agriculture, and Alliant Energy, among others. In the spring of 2006 the project conducted a three- month test burn of switchgrass at a coal-fi red station in Iowa, and has yielded some promising results. The project involved over 31 thousand bales of Iowa-grown switchgrass, totaling more than 15 thousand tons of biomass fuel. The switchgrass fuel generated more than 19 million kilowatt hours of electricity, which can meet the electrical energy needs of more than 1,800 homes for one year. During the burn, sulfur emissions were reduced by 62 tons and CO2 was reduced by over 50 thousand tons. The switchgrass used in this test burn replaced over 12 thousand tons of Wyoming coal with a locally produced, renewable fuel. Switchgrass can be co-fi red in coal plants for electrical energy generation, or combusted in ethanol plants for the production of cellulosic ethanol. The Chariton Valley test burn exemplifi es the applicability of this new technology, and helps us to focus on building greater effi ciencies into renewable energy technologies, with the goal of making them cost eff ective, aff ordable, and sustainable. Source: RenewableEnergyAccess.com

graziers from the South to the Midwest. In part of the continued support for CRP has order to obtain both optimum livestock for- been its documented benefi ts to wildlife. age and biomass tonnage, graze the switch- The CRP program is jointly administered grass to no less than 6 inches in the spring by the USDA Farm Service Agency (FSA) and or early summer, and allow the grass to regrow for a late fall or winter biomass and the Natural Resources and Conser- harvest. Switchgrass stands tend to decline vation Service (NRCS), and once land over the years with more frequent defoli- is entered into the program there are limi- ation events (grazing, haying, or biomass tations on how it can be used. Your local harvest), so careful attention to timing of FSA or NRCS office can provide you harvest, number of harvests, and regrowth with more information on CRP and is crucially important. the applicability of biomass production on CRP lands. Switchgrass for biofuel production has been considered for use on Conservation Researcher David Bransby’s test plots of Reserve Program (CRP) land in the more switchgrass at Auburn University have erodible regions of the tall-grass prai- produced up to 15 tons of dry biomass rie states. Compared per acre, with a six-year yield average Cost Variables in Switchgrass to annual cropping in of 11.5 tons per acre. Figuring roughly Production these areas, switch- 100 gallons of ethanol produced per ton A short list of items to consider in calculat- grass for biofuels could of feedstock, these switchgrass yields are ing the cost of producing switchgrass… increase the ecologi- enough to make 1,150 gallons of ethanol • land – rent, land payments, cal sustainability of the per acre each year (Biofuels from Switch- taxes, opportunity cost prairies while lowering grass: Greener Energy Pastures, Oak Ridge National Laboratory, Tennessee). Corn • establishment – fuel, seeds, till- the cost of the CRP pro- age and planting equipment, gram. However, CRP ethanol feedstocks cost ethanol producers weed control, fertility, labor rules would have to an estimated 40 to 53 cents per gallon of ethanol produced. Switchgrass feedstock • crop maintenance – weed con- be substantially modi- trol, equipment repair, fertility, fied to allow such an costs per gallon of ethanol produced would labor, etc. economic use of CRP need to be low enough (less than 40 cents • harvest – equipment, fuel, lands. Consideration of per gallon) to at least compete with corn baling materials, labor the wildlife impacts of ethanol to make cellulosic ethanol pro- economic harvesting of duction a cost-effective fuel. Currently, • transport – fuel, equipment, custom hauling, storage CRP would also become cellulosic feedstock costs per gallon of eth- loss, labor an important consider- anol produced are much higher than for ation as an important corn ethanol. Page 8 ATTRA Switchgrass as a Bioenergy Crop It is important to remember that the switch- But many other perennial warm-season grass market is still very immature, and grasses may possess these same characteris- much work needs to be done to under- tics and more. What makes switchgrass par- stand the costs of conversions and devel- ticularly suitable as an ethanol feedstock? In opment of local processing plants and research trials beginning in the mid-1980s, marketing outlets. To learn more about the Department of Energy began to seek marketing switchgrass for biofuel produc- plant species that would yield high quality tion, see the Resources section at the end and quantity biofuel feedstocks. Among the of this paper. plants considered were reed canarygrass and switchgrass, among some other grasses Other Cellulosic Feedstocks and legumes. In the trials, switchgrass had the highest yields and breeding work was Switchgrass is not the only or possibly even subsequently focused on switchgrass to the the best biomass species for cellulosic eth- exclusion of the others. urrently, anol production, but it does possess some cellulosic ecological characteristics that make it a Other sources of cellulosic feedstock under very good candidate. Among its positive investigation are forest residue, wheat straw, Cfeedstock qualities, switchgrass offers: (leaves, stalks and cobs), rice costs per gallon of straw, and bagasse (sugar cane waste), ethanol produced are • pest and disease resistance, other crop residues, municipal solid wastes, much higher than for • high yields of cellulose, poplar, and willow trees. David Bransby of corn ethanol. • low fertility needs, Auburn University suggests that, while eth- • cultivars that are locally adapted anol will not be able to completely replace and relatively available, fossil fuels for transportation and electricity, the diversity of cellulosic feedstock materi- • excellent wildlife habitat, als available can go a long way to increasing • carbon sequestration in its extensive our energy independence by making cellu- and very deep root system, losic ethanol more attainable. Coupled with • tolerance of poor soils and wide conservation, biomass fuels can provide for variations of soil pH, a portion of U.S. energy needs. • drought and flood tolerance External technical review for this publica- (depending on the ecotype and tion was provided by David Parrish, Crop variety), and and Soil Environmental Sciences, Virginia • efficient water use in grassland Tech, and Alan Teel, Iowa State University ecosystems. Extension, retired.

References and Resources Farm Energy Resources from ATTRA, National Sustainable Agriculture Information Service, Agricultural Marketing Resource Center, the National www.attra.org/energy.html, 800-346-9140 (English), Information Resource for Value-Added Agriculture. Switchgrass website: www.agmrc.org/agmrc/ 800-411-3222 (Español). commodity/biomass/switchgrass/switchgrass.htm Greer, D. 2005. Creating Cellulosic Ethanol: Spinning Comis, D. 2006. Switching to Switchgrass makes Straw into Fuel, in Biocycle, May 2005 eNews Bul- Sense, in Agricultural Research, July. USDA-ARS. letin. www.harvestcleanenergy.org/enews/enews_0505/ www.ars.usda.gov/is/AR/archive/jul06/grass0706.pdf enews_0505_Cellulosic_Ethanol.htm Costs of Producing Switchgrass for Biomass in South- Greene, N. 2004. Growing Energy: How Biofuels ern Iowa, Iowa State University Extension Publica- Can Help End America’s Oil Dependence. New York: tion PM 1866. www.extension.iastate.edu/Publications/ National Resources Defense Council. PM1866.pdf www.nrdc.org/air/energy/biofuels/biofuels.pdf www.attra.ncat.org ATTRA Page 9 Henning, J.C. 1993. Big Bluestem, Indiangrass and Parrish, D.J. and J.H. Fike. 2005. The Biology and Switchgrass. Department of Agronomy, University Agronomy of Switchgrass for Biofuels, in Critical of Missouri. http://muextension.missouri.edu/explore/ Reviews in Plant Sciences, 24:423-459. agguides/crops/g04673.htm Pimentel, D. and T.W. Patzek. 2005. Ethanol Produc- Iowa Department of Natural Resources, Switchgrass tion Using Corn, Switchgrass, and Wood; Biodiesel Program, www.iowadnr.com/energy/renewable/ Production Using Soybean and Sunfl ower, in Natural switchgrass.html Resources Research, Vol. 14, No.1, March. McLaughlin, S., J. Bouton, D. Bransby, B. Conger, W. Renewable Energy Access.com. 2006. Switch- Ocumpaugh, D. Parrish, C. Taliaferro, K. Vogal, and grass Burn Test Proves Hopeful. Accessed July 17, S. Wullschleger. 1999. Developing Switchgrass as a 2006 from www.renewableenergyaccess.com/rea/news/ Bioenergy Crop, in Perspectives on new crops and new story?id=45188 uses. J. Janick (ed.), Alexandria, VA: ASHS Press. Teel, A. and S. Barnhart. 2003. Switchgrass Seeding www.hort.purdue.edu/newcrop/proceedings1999/ Recommendations for the Production of Biomass Fuel v4-282.html in Southern Iowa. Iowa State University Extension. www.extension.iastate.edu/Publications/PM1773.pdf Morris, D. 2005. The Carbohydrate Economy, Biofu- els and the Net Energy Debate. Minneapolis: Institute Teel, A., S. Barnhart, and G. Miller. 2003. Manage- for Local Self-Reliance. www.newrules.org/agri/ ment Guide for the Production of Switchgrass for netenergyresponse.pdf Biomass Fuel in Southern Iowa. Iowa State University Extension. www.extension.iastate.edu/Publications/ Oak Ridge National Laboratory. No date. Biofuels PM1710.pdf from Switchgrass: Greener Energy Pastures. Oak Ridge, TN: Bioenergy Feedstock Development Pro- Vogel, K., and R. Masters. 1998. Developing Switch- gram. Accessed July 31, 2006 from grass into a Biomass Fuel Crop for the Midwestern http://bioenergy.ornl.gov/papers/misc/switgrs.html USA. Agricultural Research Service, USDA, Univer- sity of Nebraska, Lincoln. Paper presented at BioEn- Oregon State University. 2006. Forage Information ergy ‘98: Expanding Bioenergy Partnerships, Madi- System. Accessed May 24, 2006, son, Wisconsin, October 4-8. http://bioenergy.ornl.gov/ http://forages.oregonstate.edu/index.cfm papers/bioen98/vogel.html

Notes

Page 10 ATTRA Switchgrass as a Bioenergy Crop Notes

www.attra.ncat.org ATTRA Page 11 Switchgrass as a Bioenergy Crop By Lee Rinehart NCAT Agriculture Specialist © 2006 NCAT Paul Driscoll, Editor Amy Smith, Production This publication is available on the Web at: www.attra.ncat.org/attra-pub/switchgrass.html or www.attra.ncat.org/attra-pub/PDF/switchgrass.pdf IP302 Slot 297 Version 100506

Page 12 ATTRA