Biomethane potential of an old plantation of giant reed genotypes with two irrigation levels

Giant reed (Arundo Donax L.) is a perennial, non-food and low-input energy crop representing a promising solution to produce renewable energy at low cost, especially in marginal areas - i.e. low profitable areas which are prone to land abandonment. This research investigates the effect of two levels of irrigation (100% ETm and rainfed) on a 20-year old plantation of 40 genotypes of giant reed (Arundo donax L.) collected around Southern Italy. The experimental methanogenic potential of the biomass was defined trough the BMP test (Biochemical Methane Potential). The trial shows that several genotypes maintain high biomass yield and thus high biomethane potential yield even from old plantations. The variability of biomass yield and biomethane potential yield among genotypes is high. Giant reed genotypes show a positive response to the irrigation, which represent the main limiting factor in Mediterranean environments.