Research Article Switchgrass Cultivar/Ecotype Selection and Management for Biofuels in the Upper Southeast USA

Copyright © 2014 Rocky Lemus et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Switchgrass (Panicum virgatum L.), a perennial warm-season grass indigenous to the eastern USA, has potential as a biofuels feedstock.The objective of this studywas to investigate the performance of upland and lowland switchgrass cultivars under different environments andmanagement treatments. Four cultivars of switchgrass were evaluated from 2000 to 2001 under twomanagement regimes in plots established in 1992 at eight locations in the upper southeastern USA. Two management treatments included 1) a single annual harvest (in late October to early November) and a single application of 50 kg N/ha/yr and 2) two annual harvests (in midsummer and November) and a split application of 100 kgN/ha/yr. Biomass yields averaged 15Mg/ha/yr and ranged from 10 to 22Mg/ha/yr across cultivars, managements, locations, and years.Therewas no yield advantage in taking two harvests of the lowland cultivars (Alamo and Kanlow). When harvested twice, upland cultivars (Cave-in-Rock and Shelter) provided yields equivalent to the lowland ecotypes. Tiller density was 36 % lower in stands cutting only once per year, but the stands appeared vigorous after nine years of such management. Lowland cultivars and a one-cutting management (after the tops have senesced) using low rates of applied N (50 kg/ha) are recommended. 1