Laboratory Report

Energy from Switch Grass
As early settlers moved west from the eastern forests, they encountered a head-high sea of grasses. The soils were high in organic matter and rich in nutrients, yet attempts to cultivate the soils were seldom successful, because the root systems of the grasses extended eight to ten feet deep. In 1837, the steel plow was invented, and that changed many things. Under cultivation, the soils were subjected to erosion, leaching, and nutrient and water depletion. In light of the current energy crisis, researchers are exploring the value of the land for raising plants high in cellulose, which can be used to produce ethyl alcohol (ethanol), thanks to advances in cellulose fermentation. Work in Washington’s Yakima Valley with switch grass (Panicum virgatum), grown on soils somewhat drier than those in the Great Plains, showed that switch grass and possibly other prairie grasses could be a viable resource for the production of ethanol.

Switch grass can be harvested twice in a season, yielding as much as ten tons of biomass per acre and one hundred gallons of ethanol. The advantages of this over ethanol from corn are many. The amount of energy derived from corn et...