Biomass Partitioning in a Giant Reed (Arundo Donax L.) Crop: A Three-Year Study

Abstract

Perennial rhizomatous grasses (PRGs) are seen as a feasible opportunity to produce second generation biofuels. Among PRGs, giant reed (Arundo donax L.) is a promising energy crop, particularly for the Mediterranean environment characterized by low precipitation and high evapotranspiration rates during the summer period. The species is in fact robust and able to thrive in a wide range of soil types and under drought conditions. However, it remains a major challenge to better understand the yield potential and the crop responses to marginal soils, such as those where water and nutrients may represent limiting factors. In this work we evaluated giant reed aboveground and belowground biomass partitioning, from the establishment to the third year, in a marginal soil. Giant reed showed a significant increment of the rhizome biomass, reaching values of about 16 t ha in the third year. Maximum total aboveground biomass increased steeply from the first to the second year, while a slight increase was highlighted from the second to the third one (20 t ha). Furthermore, our data suggest that, in a limiting environment, after three years the crop was not fully established yet. In conclusion, giant reed shows quite a good adaptability to marginal land, in particular those characterized by a low water retention capacity.