John Valentine

Land-use change to bioenergy production in Europe: implications for the greenhouse gas balance and soil carbon

Bioenergy from crops is expected to make a considerable contribution to climate change mitigation. However, bioenergy is not necessarily carbon neutral because emissions of CO2, N2O and CH4 during crop production may reduce or completely counterbalance CO2 savings of the substituted fossil fuels. These greenhouse gases (GHGs) need to be included into the carbon footprint calculation of different bioenergy crops under a range of soil conditions and management practices. This review compiles existing knowledge on agronomic and environmental constraints and GHG balances of the major European bioenergy crops, although it focuses on dedicated perennial crops such as Miscanthus and short rotation coppice species. Such second‐generation crops account for only 3% of the current European bioenergy production, but field data suggest they emit 40% to >99% less N2O than conventional annual crops. This is a result of lower fertilizer requirements as well as a higher N‐use efficiency, due to effective N‐recycling. Perennial energy crops have the potential to sequester additional carbon in soil biomass if established on former cropland (0.44 Mg soil C ha−1 yr−1 for poplar and willow and 0.66 Mg soil C ha−1 yr−1 for Miscanthus). However, there was no positive or even negative effects on the C balance if energy crops are established on former grassland. Increased bioenergy production may also result in direct and indirect land‐use changes with potential high C losses when native vegetation is converted to annual crops. Although dedicated perennial energy crops have a high potential to improve the GHG balance of bioenergy production, several agronomic and economic constraints still have to be overcome.

Food vs. fuel: the use of land for lignocellulosic ‘next generation’ energy crops that minimize competition with primary food production

This review addresses the main issues concerning anticipated demands for the use of land for food and for bioenergy. It should be possible to meet increasing demands for food using existing and new technologies although this may not be easily or cheaply accomplished. The alleviation of hunger depends on food accessibility as well as food availability. Modern civilizations also require energy. This article presents the vision for bioenergy in terms of four major gains for society: a reduction in C emissions from the substitution of fossil fuels with appropriate energy crops; a significant contribution to energy security by reductions in fossil fuel dependence, for example, to meet government targets; new options that stimulate rural and urban economic development, and reduced dependence of global agriculture on fossil fuels. This vision is likely to be best fulfilled by the use of dedicated perennial bioenergy crops. We outline a number of factors that need to be taken into account in estimating the land area available for bioenergy. In terms of provisioning services, the value of biofuels is estimated at

Integration, expression and inheritance of transgenes in hexaploid oat (Avena sativa L.)

54.7‒

Chapter 15:Developing Miscanthus for Bioenergy

330 bn per year at a crude oil price of

New opportunities for the exploitation of energy crops by thermochemical conversion in Northern Europe and the UK.

100 per barrel. In terms of regulatory services, the value of carbon emissions saved is estimated at

Morphological and biochemical characterization of spikelet development in naked oats (Avena sativa)

56‒

Breeding Miscanthus for bioenergy

218 bn at a carbon price of

One hundred years of progress in cereal breeding from Mendel to molecular selection - Oats

40 per tonne. Although global government subsidies for biofuels have been estimated at

Harnessing natural variation in phenotypic and chemotypic traits in Miscanthus for breeding improved bioenergy crops: a review of long term results from perennial energy cropping work at IBERS.

20 bn (IEA, 2010b), these are dwarfed by subsidies for fossil fuel consumption (

Development and use of markers for oil in oats

312 bn; IEA, 2010b) and by total agricultural support for food and commodity crops (