Introduction
Originated from energy crops, biofuels are increasingly being considered as a sustainable energy source when compared with fossil carbon sources. Interrelated factors have led to increased demand for this green energy. Factors include increased energy demand due to resource depletion and instability in oil producing regions, recent technological breakthroughts in agriculture and concerns over environmental impacts such as climate change (Hall et al., 2009). Biofuel development is in addition driven by rural development, job creation (Kraeussl et al., 2004), increasing energy self-suciency and improving competitiveness (EC, 1996, 1997). In Europe, conventional energy crops appear like widely marketed productions, after Brazil and the USA. This expansion has been spurred by the
Kyoto Protocol signed in December 1997 and by the European energy policy. Neverthless, food crops and residues from forestry and agriculture cannot provide all biomass needed to fulll the high future demand. As a result, second generation biofuels originated from perennial biomass crops has been developed. These crops are characterized by a high land use eeciency and their production indicates a substantial reduction in GreenHouse Gas (GHG) emissions. Among others these crops are annually harvested perennial crops like miscanthus.
Miscanthus (Miscanthus x Giganteus)1 is a perennial rhizomatous grass which has its origins in the tropics and subtropics, but dierent species are found throughout a wide climatics range in East
Asia (Greef & Deuter, 1993). The remarkable adaptability of miscanthus to dierent environment
(Numata, 1974) makes it suitable for establishment and distribution under a range of European and North American climatic conditions (Lewandowski et al., 2000). Physiologically, miscanthus, like maize, is a C4 species, xing carbon by multiple metabolic path-ways with a high water use eciency (Koshi et al., 1982; Moss et al., 1969). Miscanthus roots can penetrate to a depth of around 2 meters, which can provide a good protection against soil erosion. Even though its high biomass yield potential, this crop requires low input level and therefore involves decreasing risk of ground water pollution by pesticides and nitrates. Miscanthus is generally harvested in early spring, which allows for good combustion quality due to low water content in addition to the fact that it contains low ash, N, chloride, potassium (Lewandowski et al., 2003).
According to the Renewable Energy Directive, the French government is committed