Willow biomass obtained from different soils as a feedstock for energy

Abstract

Perennial energy crops, including willow, should be highly productive and the biomass should possess a high energy value, allowing farmers to obtain large amounts of energy per ha each year. The aim of this study was to determine the morphological traits, biomass productivity and quality of willow coppice grown on two different soil sites and harvested in a three-year cycle. The experiment was performed on a commercial willow plantation owned by the University of Warmia and Mazury in Olsztyn (the UWM). The plantation, located in north-eastern Poland, covered 4.7ha. The study demonstrated that the UWM 043 cultivar grown in a three-year rotation system on Haplic Cambisols (Eutric) soil can produce plants over 8m tall with shoots over 4cm in diameter. On the other hand, plants of Salix spp. grown on much poorer soil are much shorter and have thinner shoots. Under optimal production conditions, it is possible to harvest in a three-year rotation system as much as 16.12Mgha−1year−1 of dry biomass per year with moisture equal to 47.56%. The yield of the UWM 043 cultivar was significantly (40%) higher than that of the cultivar Turbo. The biomass of the UWM 043 clone proved to be better fuel owing to a higher bulk density, lower moisture, higher lower heating value and a lower content of nitrogen, sulphur and chlorine.