RECLAMATION OF MINED LAND WITH SWITCHGRASS, MISCANTHUS, AND ARUNDO FOR BIOFUEL PRODUCTION 1

Abstract

Use of biomass to supplement the nation's energy needs for ethanol production and green fuel for power plants has created a demand for growing reliable feedstocks. Switchgrass (Panicum virgatum L.), miscanthus (Miscanthus x giganteus), and giant cane (Arundo donax L.) are possible biofuel crops because they produce large amounts of biomass over a wide range of growing conditions, including marginal and reclaimed land. West Virginia's climate and large acreage of available reclaimed mine land provide a land base to generate high amounts of biomass for a biofuel industry. The purpose of this study was to determine the yield of three biomass crops on reclaimed mined land in central West Virginia. A 25-year-old reclaimed site near Alton, WV was prepared using herbicides to eliminate all existing cool-season vegetation on a 5-ha area. Twenty-three plots of 0.4-ha in size were established. Mine soil samples showed an average pH of 7.5 and adequate supplies of plant nutrients. Two switchgrass varieties (Kanlow and BoMaster) were randomly assigned to 10 plots (five replications) and seeds were drilled into the killed sod at a rate of 11 kg ha -1 . Two types of miscanthus (sterile public and private varieties) were randomly assigned to 10 plots and planted with seedling plugs on 0.8-m centers. Giant cane was assigned to three plots and rhizomes were planted on 1.5-m centers. Yield measurements were taken in September the second and third years after planting. Yields for Kanlow switchgrass varied from an average of 4,000 kg ha -1 in 2011 to 4,900 kg ha -1 in 2012. BoMaster switchgrass was lower at 2,750 kg ha -1 in 2011 and 3,981 kg ha -1 in 2012. The public variety of miscanthus showed yields 7,500 kg ha -1 in 2011, but decreased to an average of 4,900 kg ha -1 in 2012. The private miscanthus variety was much greater at 21,880 kg ha -1 in 2011 and 15,500 kg ha -1 in 2012. Giant cane yields were low with an average yield of 515 kg ha -1 in 2012. Survival and growth of giant cane was hindered by weed competition and poor establishment. Target yields for reclaimed lands, as established by the WV Department of Environmental Protection of 5,000 kg ha -1 for switchgrass and 15,000 kg ha -1 for miscanthus were not attained with switchgrass and the public variety of miscanthus, but was achieved with the private variety of miscanthus. More time may be needed for these yield goals to be achieved as stands continue to develop over time.