CONTENT OF CARBON, HYDROGEN AND SULPHUR IN BIOMASS OF SOME SHRUB WILLOW SPECIES

Carbon, hydrogen and sulphur were determined in biomass (shoots and roots) of five species of shrub willow: Salix viminalis, Salix dasyclados, Salix triandra., Salix purpurea and Salix alba. Samples of the biomass collected from a strict experiment were dried to constant weight at 105 degrees C. The content of carbon, hydrogen and Sulphur was determined in an automatic determinator ELTRA CHS 500. In addition to the chemical determinations, willow plants were assessed, in the first year of cultivation, in terms of their morphological traits and yields. The results underwent statistical analysis using Excel spreadsheets and Statistica PL software programme. An average content of carbon in the biomass of the five analysed willow species was 496.33 g.kg(-1) d.m. Among the five species, the highest carbon content was discovered in the biomass of Salix purpurea (501.32 g.kg(-1) d.m.). An average content of hydrogen in aerial parts of shrub willow was significantly higher than in their roots (507.95 vs 465.88 kg(-1).d.m.). The content of hydrogen in all the species of shrub willow was on average 71.11 g.kg(-1) d.m., with the highest hydrogen amount in biomass attributed to Salix triandra (74.98g.kg(-1) d.m.). This species, on the other hand, had the lowest concentration of sulphur in its biomass (on average 0.43 g.kg(-1) d.m.). The average content of sulphur in aerial parts was significantly lower than in roots of willow plants (0.52 vs 0.95 g.kg(-1) d.m.). This relationship held true for all the five species of willow plants. An average yield of dry biomass obtained from the five shrub willow species in the year when the experiment was established was 5.81 Mg.ha(-1). The highest dry biomass yield was produced by Salix viminalis (7.22 Mg.ha(-1)).