Submitted to: Seed Production Research at Oregon State University
Publication Type: Experiment Station
Publication Acceptance Date: February 20, 2008
Publication Date: April 1, 2008
Citation: Banowetz, G.M., El Nashaar, H., Griffith, S.M., Steiner, J.J. 2008. Mineral characterization of temperate grasses from a high rainfall environment. Seed Production Research at Oregon State University. 127: 70-72. Technical Abstract: Straw produced as a co-product of perennial ryegrass (Lolium perenne L.), orchardgrass (Dactylis glomerata L.), tall fescue [Schedonorus phoenix (Scop.) Holub] (formerly Festuca arundinacea Schreb.), and Kentucky bluegrass (Poa pratensis L.) seed production in the high rainfall area of western Oregon as well as clippings from urban and recreational turf 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 selected 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 (Tables 1 and 2). Minerals that represent soil nutrients removed with straw harvests also were quantified to aid evaluation of the sustainability of straw removal as bioenergy feedstock. 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 that genotypic variability in mineral accumulation may be exploited to develop germplasm with improved mineral uptake traits. Aside from N, soil K and P can be limited in some soils, removal of straw can affect long-term soil fertility if left unchecked by mining available soil K and P. Table 3 shows the amounts of K and P removed per ton of straw.