Switchgrass is a tall North American grass being developed as a renewable source of energy. It reaches 6 to 10 feet (2 to 3 meters) tall, with thick stems that grow in clumps. The stems develop a feathery seed head (flowering structure). Switchgrass’s leaves are yellowish- to bluish-green and grow to about 1 foot (30 centimeters) long. Switchgrass is a perennial—that is, its roots live through the winter and grow new grass each year.
Before the Great Plains were plowed for farming, switchgrass helped form vast prairies. It provided food for huge numbers of buffalo, deer, and antelope. In the late 1900’s, farmers put switchgrass to similar use by planting it to provide forage (livestock feed).
Since the 1990’s, farmers and scientists have been interested in switchgrass as a source of biofuel. Biofuels are made from plant matter, animal waste, or other biological material. The leaves and stems of switchgrass can be processed to make biofuels, such as ethanol.
Switchgrass has attracted biofuel researchers for several reasons. It can produce 6 to 10 tons of leaves and stems per acre (13 to 22 metric tons per hectare) annually. As a result, switchgrass can produce more biofuel than such sources as corn on the same planted area. Switchgrass also grows in poorer soils with less fertilizer than corn. It is more resistant to heat and drought, and it helps reduce soil erosion. In the Great Plains, switchgrass is a native plant, and it provides abundant cover for wildlife. Switchgrass may become a major source of biofuel as people develop the technology to make fuel from switchgrass at a profit.
See also Ethanol ; Renewable energy .
