Submitted to: Biomass and Bioenergy
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/24/2008
Publication Date: 4/1/2009
Citation: Burner, D.M., Tew, T.L., Harvey, J.J., Belesky, D.P. 2009. Dry matter partitioning and quality of Miscanthus, Panicum, and Saccharum genotypes in Arkansas, USA. Biomass and Bioenergy. 33(4):610-619. Interpretive Summary: The US is striving to increase its production of energy from domestic renewable sources. The conversion of cellulose-containing biomass to ethanol could be a significiant source of energy. However, numerous aspects of this emerging industry remain unresolved: an economical conversion method; site-appropriate feedstocks; feedstock yield, chemical composition, and energy level; mechanical harvesting methods; biomass storage; economical hauling distance to conversion factories; and regional production levels. Our objective was to examine biomass yield and chemical composition of five cold tolerant grasses. ARS scientists from Booneville, AR found that the sugarcane clone US84-1028 yielded more than other entries in 2004, while switchgrass, US84-1028, and M. x giganteus did not differ in yield in 2005. The sugarcane clone US84-1028 also had greater dry mass/stem and leaf dry mass/stem than other entries both years. This information expands our knowledge of site-appropriate, alternative biomass crops. The selection of cold tolerant sugarcane should encourage the breeding and cultivation of sugarcane for energy outside its primary production regions.
Technical Abstract: The partitioning and quality of aboveground biomass have important ramifications for crop management and biomass conversion. In preliminary studies, small samples of Saccharum sp. x Miscanthus sp. hybrids exhibited stubble cold tolerance in west-central Arkansas, unlike Saccharum sp. x S. spontaneum hybrids. The objective was to examine foliar and stem quality of the C4 grasses Miscanthus sinensis ('Gracillimus'), M. x giganteus (Q42641, proprietary), Panicum virgatum ('Alamo'), and two F1 hybrids of Saccharum sp. x Miscanthus sp. (US84-1028 and US84-1058) in a field study during 2004 (plant cane) and 2005 (first subble) near Booneville, AR. Switchgrass produced more stems/square m than the other entries both years, and there was little difference in stem number among other entries. Clone US84-1028 yielded more dry mass per square m than other entries in 2004, while switch grass, US84-1028, and M. x giganteus did not differ in 2005. Clone US84-1028 also had more dry mass/stem and leaf dry mass/stem than other entries both yr. Tissue N concentrations were low for these entries, but leaves (less than or equal to 15.2 g/kg)contained about twice the N of stems (less than or equal to 7.8 g/kg). Leaves represented as much as one-third of total biomass, and had sufficient cellulose (less than or equal to 482 g/kg) and lignin (167 g/kg) concentrations to warrant harvesting for maximum energy production. The competitively high biomass yield of this small sample of sugarcane alleles should encourage the expansion of cold tolerant energy cane beyond the current production regions. Sugarcane and M. x giganteus should be examined in highter-input temperate systems because of their bioenergy potential.