Submitted to: Energy and Fuels
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 30, 2008
Publication Date: March 27, 2009
Citation: Banowetz, G.M., Griffith, S.M., Steiner, J.J., El Nashaar, H.M. 2009. Mineral accumulation by perennial grasses in a high rainfall environment. Energy and Fuels. 23:984-988. Interpretive Summary: Straw produced from grass seed production in the high rainfall region of western Oregon has potential to be used as feedstock for biofuel production. Most straws, however, contain large quantities of minerals that prevent their efficient use in high temperature processes to convert the straw to energy. Although plant breeders improve grasses for many other purposes, the potential of using conventional plant breeding to select grasses with reduced mineral content is not known. This study quantified the concentration of minerals in a multiple varieties of tall fescue, perennial ryegrass, and Kentucky bluegrass and found that there is variation in mineral accumulation that may be exploited by plant breeders to improve the biofuel quality of straw.
Technical Abstract: Straw produced as a co-product of perennial ryegrass (Lolium perenne L.), orchardgrass (Dactylis glomerata), tall fescue (Schedonorus phoenix (Scop.) Holub), and Kentucky bluegrass (Poa pratensis L.) seed production in the high rainfall area of western Oregon as well as clippings from urban and recreational turfs developed from this seed have potential for use as biofuel feedstock. Previous efforts to convert this biomass to energy utilizing thermochemical approaches were plagued by the presence of “anti-quality” mineral constituents that impact the long-term durability of gasification reactors. There is potential for genetic improvement of these grasses to enhance their suitability as feedstock for these reactors, but little is known about genotypic variability in mineral accumulation by these species. Mineral content of straw from multiple cultivars of each species collected from multiple locations within the high rainfall production region were quantified and mineral distribution within the plant was determined. Significant (P < 0.01) variability in the amount of critical “anti-quality” minerals including calcium (Ca), chlorine (Cl), potassium (K), silicon (Si), and sulfur (S) were found, though differences in S were small. Minerals that represent soil nutrients removed with straw harvests also were quantified. Mineral accumulation varied between species and was dependent upon factors other than soil mineral content. Differences between cultivars and species collected from the same location suggest the existence of genotypic variability in accumulation of these minerals.