The aim of this thesis is the evaluation of fast growing tree species with alternative ways of fertilization. This thesis focuses on production of fast growing willows, from which was selected the clone Tordis. In this thesis site is described where the research was applied, methodology of production analysis for fast growing tree species with use of the alternative fertilizers. On the plantations, production was analyzed on three sites during two vegetation periods. On two sites, there were two alternative ways of fertilization used. Third site was left as reference site without fertilization, so the quantification of difference on increments between sites would be possible. After the measurements, the harvesting was performed and then calculations were made to assess dry weight of willow produced on the sites under different way of fertilization. As alternative fertilizers were used sewage sludge from the waste water treatment plant and wood ash. Chemical and physical properties of these fertilizers are covered within this thesis as well as legislative conditions applied in Slovakia. At the end of this thesis are evaluated the results and their benefits for growth of fast growing willows. Also gained experience with the use of alternative fertilizers and the analysis of the results are listed, so they can be applied in further follow-up research and practice.