Managing and enhancing switchgrass as a bioenergy feedstock

Abstract

The United States Department of Energy (DOE) has identifi ed switchgrass (Panicum virgatum L.) as a viable perennial herbaceous feedstock for cellulosic ethanol production. Although switchgrass bioenergy research was initiated by USDA-ARS, Lincoln, NE, USA in 1990, switchgrass research has been conducted at this location since the 1930s. Consequently, a signifi cant amount of genetic and agronomic research on switchgrass has been conducted for the Corn Belt and Central Great Plains of the USA that is directly applicable to its use as a biomass energy crop. Similar research must be conducted in other major agroecoregions to verify or modify switchgrass management practices (agronomics) for bioenergy production. The technology to utilize switchgrass for producing ethanol using a cellulosic platform or by pyrolysis to generate syngas is advancing rapidly. Regardless of platform, using switchgrass for ethanol production will require the development of improved bioenergy cultivars or hybrids and improved agronomics to optimize production and will introduce competing uses for the land base. Published in

Dedicated Energy Crops and Crop Residues for Bioenergy Feedstocks in the Central and Eastern USA

“…Biomass-based systems will require enormous quantities of material. For example, a 300 million L per year plant will require 907,000 DM Mg of feedstock year −1 or 2490 DM Mg of feedstock day −1 , requiring 222 ha of feedstock yielding 11.2 DM Mg ha −1 [1]. Significant breeding progress has been made on many of the dedicated energy crops, with yields exceeding 20 DM Mg ha −1 in much of the region.…”

“…However, on marginally productive cropland, perennial grasses may provide a reliable feedstock supply while providing enhanced ecosystem services. Mitchell et al [1] focused on four primary advantages that perennial feedstocks have over annual crops such as corn. First, perennials have less annual establishment input requirements.…”

Categories of Resistance to Greenbug and Yellow Sugarcane Aphid (Hemiptera: Aphididae) in Three Tetraploid Switchgrass Populations

“…As an example, in the related native warm-season perennial, buffalograss, Buchloë dactyloides (Nuttall) Engelmann, an emergence in multiple important pests was demonstrated with increased use of this species as a turfgrass [4,16]. Likewise, recent work has demonstrated that insect problems may occur, particularly as production increases [1,9,22,28]. In 2004, a poorly understood species, Blastobasis repartella (Dietz), was rediscovered, and appears to be a monophagous stem-borer restricted to switchgrass [1,28].…”

“…Additionally, other important insect pests have been more incidentally documented in association with switchgrass, including grasshoppers (Acrididae) [27,38]. As a result, the prevalence of those and other potential pests in switchgrass may increase as the agricultural landscape changes to accommodate increased production of bioenergy feedstocks [5,22].…”

Biomass Yield of Warm‐Season Grasses Affected by Nitrogen and Harvest Management

“…However, in Iowa and Nebraska, N fertilization for 'Cave-inRock' switchgrass at 120 kg ha -1 produced dry matter yields between 10.5 to 12.6 Mg ha -1 while removing approximately the same amount of N from the soil (Vogel et al, 2002). Investigations show that switchgrass N fertilizer requirements depend on the yield potential of the site, productivity of the cultivar, and harvesting schedule (McLaughlin et al, 1999;Mitchell et al, 2008;Anderson et al, 2013). Removal of a significantly greater portion of applied N in the two-cut system compared to single cut system (McLaughlin et al, 1999) is an example of the impact of harvesting regime on the N fertilizer requirement.…”