Are the environmental benefits of Miscanthus × giganteus suggested by early studies of this crop supported by the broader and longer‐term contemporary studies?

Abstract

Are the environmental benefits of Miscanthus 3 giganteus suggested by early studies of this crop supported by the broader and longer-term contemporary studies? T H O M A S B . V O I G T , G u e s t E d i t o rThe high yields of Miscanthus 9 giganteus as a bioenergy crop has attracted much recent interest (U.S. Department of Energy, 2011). On about two-thirds of the 18 M ha potentially available for bioenergy crops in the US, M. 9 giganteus could potentially provide sufficient biomass to meet the goal of replacing 133 billion liters of petroleum of the Energy Independence and Security Act (Heaton et al., 2008;Somerville et al., 2010). In Europe, M. 9 giganteus is emerging as a major combustion feedstock as its largest single thermal electricity power generation station, Drax B, moves to 50% renewable. As increasing experience is gained with this new crop, will it deliver the yields, sustainability, and environmental benefits suggested by earlier studies? This Virtual Special Issue brings together recent articles addressing elements of this key question, the answer to which is critical to choice of crop and effective land use for expanding bioenergy production (Table 1).Based now on more than 25 years of European and just over 10 years North American biomass production experience with this crop, it can be concluded that M. 9 giganteusis emerging as a common choice for new commercial bioenergy projects both at pilot and commercial scale.Recent publications in GCB Bioenergy help us to better understand the sustainability of M. 9 giganteus bioenergy production, in terms of greenhouse gas (GHG) emissions, soil carbon accumulation, and nitrate leaching in comparison with fossil fuels and bioenergy produced from other crops. These studies range from observational and experimental fieldwork to modeling and at scales from small plots to national.Several articles deal with greenhouse gas emissions resulting from Miscanthus production. Gauder et al. (2012) compared CH 4 , CO 2 , and N 2 O emissions from N-fertilized and unfertilized M. 9 giganteus, coppiced willow, and energy maize in a one-year study. They found that CH 4 contributed very little to GHG emissions; the soil in this study actually acted as weak CH 4 sinks for all crops. Furthermore, CO 2 emissions tended to be seasonal with higher emissions in warmer seasons than in cooler seasons, and, like CH 4 , were correlated with soil temperatures. Emissions of N 2 O were increased with N fertilization for the M. 9 giganteus and energy maize, but less so for the coppiced willow. Overall, because of the high yields of the unfertilized M. 9 giganteus (average annual productivity of 16.8 dry Mg ha À1 over 5 years) and minimal N 2 O emissions, the authors recommended the production of unfertilized or 'moderately N-fertilized' M. 9 giganteus at their experimental site to maximize yield and minimize N 2 O emissions. Similarly, Drewer et al. (2012) found that CH 4 emissions were negligible and N 2 O emissions were related to N-fertilization. In this study, the N 2 O emissions ...

Relevance of environmental impact categories for perennial biomass production

“…It is a low‐input crop with a high nitrogen, land‐use and energy efficiency (Lewandowski & Schmidt, ) and has the potential to remove CO 2 from the atmosphere through carbon sequestration (Clifton‐Brown et al ., ). In an editorial regarding the environmental benefits of miscanthus, Voigt () recommends Miscanthus x giganteus ‘as the energy crop of choice’. In the context of sustainability requirements, it is important to assess the performance of each crop in economic, social and ecological terms.…”

Ecosystem Service Benefits and Trade-Offs—Selecting Tree Species in Denmark for Bioenergy Production

“…It has a high yield even in a cooler climate combined with resistance to pest and diseases [39]. As a perennial crop, it has a longer growing season and requires less agricultural input (fertilization and pesticides) than conventional crops [39][40][41]. It has a high rate of carbon sequestration in the soil, and overall lower environmental impact, and higher potential for biodiversity compared to annual crops [39,[42][43][44][45].…”

Pressures on soil functions from soil management in Germany. A foresight review

“…These systems are also considered to have some benefits for soil functions (driver soil degradation threats), including carbon sequestration (climate change mitigation) (Voigt 2015 for Miscanthus, Musshoff 2012 for SRC, Wichmann 2016 for paludiculture) ( Table 5). The stress tolerance of some secondgeneration feedstocks such as Miscanthus (Quinn et al 2015) makes them also of interest for climate change adaptation (Table 5).…”