Influence of fertilisation and harvest time on fuel quality of giant reed (Arundo donax L.) in central Italy

The perennial grass giant reed (Arundo donax L.) has been proposed as a promising biomass energy crop in southern Europe. The aim of this study was to investigate the effects of two fertilisation levels (F = 200-80-201) N-P-K kg ha(-1): UF = 0-0-0 N-P-K kg ha(-1)) and two harvest times (A: autumn, W: winter) on the biomass quality of giant reed as a solid fuel for combustion. Different aged crops grown in central Italy (latitude 43 degrees 40'N, and longitudel 10 degrees 19'E) in the period of 1996-2005 were collected and analysed. Our results confirmed that giant reed biomass is characterized by a high content of ash and silicon. Giant reed showed an increase in ash content from F to UF and from A to W. The production of biomass from fertilised crops harvested in the autumn may thus be a good method for reducing the ash content by about 20%. The results also showed an improvement in biomass combustion quality in 10-year-old crops due to a lower ash content and higher SiO2/K2O and CaO/K2O ratios, which could contribute to a lower slagging tendency. This research should help to improve our knowledge of the chemical composition of giant reed and presents possible agronomic strategies to combine a high biomass yield with good combustion quality. (C) 2010 Elsevier B.V. All rights reserved.