Most of the energy today is obtained from fossil fuels, which are becoming more expensive and less available. Energy from biomass produced on agricultural land is an alternative option. Energy crops should guarantee high yield and good quality parameters, associated with their use in energy production. This study analysed the thermophysical and chemical properties of biomass obtained from 15 new clones of willow selected in the Department of Plant Breeding and Seed Production of the University of Warmia and Mazury in Olsztyn. The plants were cultivated in one- and three-year rotation cycles, run in 2009-2011 at two research stations: in Bałdy and in Łężany. The energy content as well as elemental and physical properties of biomass were analysed. The higher heating value was was better in biomass from one-year shoots (on average 19.66 MJ kg-1 d.m.). The highest value of this parameter was recorded for the clone of Salix acutifolia UWM 093 (20.04 MJ kg-1 d.m.). The higher heating value in biomass of three-year old clones was on average lower by 0.06 MJ kg-1 d.m. The lower heating value in biomass increased in longer willow coppice harvest cycles. The highest lower heating value was recorded for the clone UWM 035 of Salix pentandra (9.27 MJ kg-1) harvested in a three-year cycle, whereas the lowest one was achieved by the clone of Salix dasyclados UWM 155 (7.55 MJ kg-1) harvested in a one-year cycle. The average moisture content in three-year shoots was 50.01% d.m., being higher by 2.31% in one-year shoots. The ash content was lower in biomass harvested in three-year rotation. In conclusion, willow biomass obtained in a three-year harvest cycle contains less of undesirable elements and proves to be better quality fuel than biomass obtained in a one-year harvest cycle.  

20.1.2015