Growth and Yield of Miscanthus 3 giganteus Grown in Fertilized and Biochar-Amended Soils in the Western North Carolina Mountains

ABSTRACT Miscanthus 3 giganteus Greef & Deu (giant miscanthus) is a perennial C4 grass grown worldwide for bioenergy production; however, there is concern about whether it can produce high yields on marginal soils in a temperate climate. The goals of this study were to determine whether giant miscanthus could establish and produce yields in Western North Carolina comparable to those in other regions and to determine whether fertilization and biochar could improve yields. At two field sites, Mills River (650 m) and Valle Crucis (830 m), fertilizer (0 and 100 kg NPK ha1) and biochar (0 and 15 t ha1) treatments were employed in a fully randomized block design. Genetically identical rhizomes were planted in spring of 2012 and allowed to grow for two growing seasons. No treatment effects were found for gas exchange, but rates were higher at Mills River than at Valle Crucis. There were no biochar or fertilizer effects on yields. First-year yields were greater at Mills River than at Valle Crucis (2.93 and 1.77 Mg dry weight [DW] ha1, respectively). Overwinter survival rates were 100% at both field sites. Second-year yields were approximately 103 greater than in the first year (27.68 Mg DW ha1 at Mills River vs. 30.12 Mg DW ha1 at Valle Crucis). The high survival and growth rates during the first 2 yr demonstrate that this bioenergy crop is capable of growing in Western North Carolina and producing yields comparable to those in other areas of the country where this crop has been grown.