Biomass Yield and Composition of 9 Switchgrass Cultivars in Eastern Canada.

Switchgrass (Panicum virgatum L.) has been identified as a high-potential energy crop. High yields and low concentrations of inorganic elements are the most important biomass characteristics sought for combustion, currently the most sustainable approach to convert switchgrass into energy. We assessed the extent of genetic variability for dry matter (DM) yield and concentrations of ash, chloride (Cl) and potassium (K) in switchgrass cultivated in eastern Canada. Nine upland switchgrass cultivars and populations were established in 2011 at five sites across the Province of Quebec, Canada. In 2012, 2013, and 2014, switchgrass cultivars and populations were fall harvested at all sites and biomass DM yield was determined. In 2012 and 2013, biomass samples of all cultivars and populations from three sites were used to determine the ash, Cl, and K concentrations. Averaged across years and sites, the highest yielding cultivars were Bluejacket, Cave-in-Rock, and Shawnee (7.8 Mg DM ha^-1) and the lowest yielding cultivar was Dacotah (3.9 Mg DM ha^-1). The cultivars with the lowest ash concentration were Bluejacket, Cave-in-Rock, Forestburg, Shawnee and Sunburst (49 to 51 g kg^-1 DM) and the cultivars with the highest ash concentration were Dacotah and Nebraska (54 and 57 g kg^-1 DM). The cultivars with the lowest K concentration were Dacotah and Forestburg (2.9 and 3.5 g K kg^-1 DM) and they both had the lowest Cl concentration along with Tecumseh (0.32 to 0.39 g Cl kg^-1 DM). The cultivars with the highest Cl and K concentrations were Cave-in-Rock, Shawnee, and Southlow (0.60 to 0.63 g Cl kg^-1 DM and 5.2 to 5.6 g K kg^-1 DM). The high yield, lower ash concentration, and intermediate Cl and K concentrations observed in Bluejacket makes it a particularly promising biomass for combustion in eastern Canada.