Year: 2011
Type: article
Abstract: The contribution of switchgrass (Panicum virgatumL.), a perennial C4grass, in reducing greenhouse gas (GHG) emissions was reviewed under three main areas; the impact on carbon dioxide (CO2), nitrous oxide (N2O), and methane emissions (CH4), whilst also taking into account the effects of land conversion to switchgrass. Switchgrass is able to enhance biomass accumulation in a wide range of environmental conditions, which is the premise for considerable carbon assimilation and storage in the belowground organs. The progress in some areas of crop husbandry (e.g., tillage and fertilization) has fostered benefits for carbon storage, while restrainingGHGemissions. As root biomass is the main indicator of soil carbon sequestration, switchgrass's dense and deep rooting is a relevant advantage, although uncertainty still exists about the crop's belowground biomass accumulation. In agreement with this, mostLCAstudies addressingCO2emissions report significant benefits from switchgrass cultivation and processing. BesideCO2, switchgrass performed better than most other biomass crops also in terms of N2O emission. In the case ofCH4emission, it may be argued that switchgrass should act as a moderate sink, i.e., contributing to mitigateCH4atmospheric concentration, but a substantial lack of information indicates the need for specific research on the topic. Land conversion to switchgrass is the latest issue which needs to be addressed inLCAstudies: not surprisingly, the netCO2abatement appears remarkable if switchgrass is grown in former arable lands, although it is slightly negative to positive if switchgrass replaces permanent grassland. In conclusion, switchgrass could significantly contribute to mitigateGHGemissions, although areas of uncertainty still exist in the assessment of soil carbon storage, N2O andCH4emissions, and the effects of converting lands to switchgrass. Further improvements must, therefore, be achieved to strengthen the crop's remarkable sustainability.
Source: GCB Bioenergy
Institution: University of Bologna
Language: English
Subfield: Agronomy and Crop Science
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W2044144652