Open Access
Kemmerer, Benjamin David
Graduate Program:
Agricultural and Biological Engineering
Master of Science
Document Type:
Master Thesis
Date of Defense:
December 21, 2010
Committee Members:
  • Jude Liu, Thesis Advisor
  • Thomas Lehman Richard, Thesis Advisor
  • Marvin H Hall, Thesis Advisor
  • Density
  • Harvest
  • Large Square Bale
  • Biomass
Large square bales currently hold great potential for harvesting and storing switchgrass biomass energy feedstocks. Producing, transporting, and storing large square bales have many advantages over both small square bale and round bale counterparts as well as other possible harvest methods. These advantages stem from the high capacity of the machines and both storage and transportation characteristics of the bales. To optimize the logistics of switchgrass as a biomass feedstock, the characteristics of harvesting switchgrass with a large square baler must be well understood. Parameters that effect switchgrass large square bale production and handling logistics are the focus of this research. A New Holland large square baler was used to harvest switchgrass biomass in May of 2010. The biomass had been cut with a discbine the previous fall and left to overwinter on the ground in order to create a spring harvest situation. The large square baler was able to produce bales that approached 200 kg/m3 at 12% (w.b.) moisture content. Fuel consumption of the tractor that powered the baler did not significantly change when different bale density setting were applied to the baler. However, the efficiency of the baler was found to be heavily dependent on windrow density and consistency. The square bale handling capabilities were then studied at a commercial farm to determine the benefits of producing denser bales in terms of labor and energy costs. Lab scale compression tests were performed to analysis the effects of harvest time and moisture content on switchgrass large square bale production. For the switchgrass samples compressed at various moisture contents, no statistical differences in the specific energy required for compression were found when only the dry matter bulk density was considered. The spring harvested samples were found to require more energy to compact than the fall harvested samples, mainly due to a decrease in the leaf to stem ratio caused by the biomass overwintering in the field.