Date of Graduation
Davis College of Agriculture, Natural Resources and Design
Growing crops for biofuel production on agricultural land has caused a debate between whether we should grow corn grain on productive, agricultural lands to feed a growing human population or to fuel our vehicles. This has increased interest in growing cellulosic biofuel feedstocks on marginal lands. Switchgrass (Panicum virgatum L.), a warm-season perennial grass, has been shown to be a viable bioenergy crop because it produces high yields on marginal lands under low water and nutrient conditions. West Virginia contains immense acreages of reclaimed surface mine lands and could offer enough area for the production of switchgrass as a feedstock for a biofuel industry.;The first study was established in 2008 to determine switchgrass yields of three different cultivars on two mine sites in West Virginia. The first site, which was reclaimed in the early 1990s using top soil and treated municipal sludge, consistently had the highest yield of the two sites with a sixth-year yield of 8.4 Mg Dry Matter (DM) ha-1 averaged across varieties. Cave-in-Rock variety produced 13.0 Mg ha-1 of biomass which was more than the other two varieties. The other site, Hobet, was prepared using crushed, unweathered sandstone in 2008 and average yields were 1.0 Mg ha-1 for the sixth year of production.;The second study was conducted on two sites which were reclaimed with a layer of topsoil over gray overburden and seeded with Cave-in-Rock 2011. Fertilizer was applied at rates of 0, 33.6, and 67 kg N ha-1. No fertilizer treatment yielded 0.32 Mg ha-1 while the fertilizer treatments produced significantly higher yields.;The objective of the third study was to determine if cultivars and samples from fertilizer treatments differed in composition and theoretical ethanol yield. Compositional analysis was done using near infrared reflectance spectroscopy. It was determined that cultivars did not differ in theoretical ethanol yield with averages ranging from 364 to 438 L Mg-1. Theoretical ethanol production from Cave-in-Rock was significantly higher ranging from 6,092 to 7,348 L ha-1 due to its high biomass production. Fertilizer treatments did not greatly effect composition of switchgrass, but since it did improve yield this was reflected in greater ethanol production for fertilized treatments. Based on the information presented here, high biomass should be the goal for switchgrass grown for biofuel production. With proper soil substrate and fertilizer regime, switchgrass grown on reclaimed surface mines may have high enough yield and quality to support ethanol production in the future.
Brown, Carol A., "Biomass production, composition, and ethanol potential of switchgrass grown on reclaimed surface mines in West Virginia" (2014). Graduate Theses, Dissertations, and Problem Reports. 5265.