Greenhouse gas emissions from four bioenergy crops in England and Wales: integrating spatial estimates of yield and soil carbon balance in life cycle analyses
Hillier, Jonathan, Whittaker, Carly, Dailey, Gordon, Aylott, Matthew, Casella, Eric, Richter, Goetz M., Riche, Andrew, Murphy, Richard, Taylor, Gail and Smith, Pete (2009) Greenhouse gas emissions from four bioenergy crops in England and Wales: integrating spatial estimates of yield and soil carbon balance in life cycle analyses. Global Change Biology Bioenergy , 1, (4), 267-281. (doi:10.1111/j.1757-1707.2009.01021.x).
Accurate estimation of the greenhouse gas (GHG) mitigation potential of bioenergy crops requires the integration of a significant component of spatially varying information. In particular, crop yield and soil carbon (C) stocks are variables which are generally soil type and climate dependent. Since gaseous emissions from soil C depend on current C stocks, which in turn are related to previous land management it is important to consider both previous and proposed future land use in any C accounting assessment.
We have conducted a spatially explicit study for England and Wales, coupling empirical yield maps with the RothC soil C turnover model to simulate soil C dynamics. We estimate soil C changes under proposed planting of four bioenergy crops, Miscanthus (Miscanthus×giganteus), short rotation coppice (SRC) poplar (Populus trichocarpa Torr. & Gray ×P. trichocarpa, var. Trichobel), winter wheat, and oilseed rape. This is then related to the former land use – arable, pasture, or forest/seminatural, and the outputs are then assessed in the context of a life cycle analysis (LCA) for each crop.
By offsetting emissions from management under the previous land use, and considering fossil fuel C displaced, the GHG balance is estimated for each of the 12 land use change transitions associated with replacing arable, grassland, or forest/seminatural land, with each of the four bioenergy crops. Miscanthus and SRC are likely to have a mostly beneficial impact in reducing GHG emissions, while oilseed rape and winter wheat have either a net GHG cost, or only a marginal benefit. Previous land use is important and can make the difference between the bioenergy crop being beneficial or worse than the existing land use in terms of GHG balance.
|Keywords:||bioenergy, greenhouse gas, LCA, miscanthus, poplar, rothC, short rotation coppice|
|Subjects:||S Agriculture > S Agriculture (General)
Q Science > QH Natural history > QH301 Biology
|Divisions:||University Structure - Pre August 2011 > School of Biological Sciences
|Date Deposited:||09 Jul 2010 13:25|
|Last Modified:||08 Jun 2012 12:54|
|RDF:||RDF+N-Triples, RDF+N3, RDF+XML, Browse.|
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