The paper presents the influence of mineral fertilization (NPK) and waste activated sludge (applicated in two doses) on the yield (stems growing in two periods during two years) of three species of willow (Salix caprea, Salix alba and Salix purpurea) harvested in the second and forth year of cultivation. The plants were grown in the conditions of central eastern part of Poland in the years 2001-2005. The field experiment was laid out in the completely randomized scheme. It was found that the best yielding species was Salix caprea. The yield of two-year stems of cultivated species of willow was significantly higher in the fourth than in the second year of cultivation. Mineral fertilization (NPK) caused an increase in the yield of stems harvested in both periods of cultivation, whereas fertilization with waste activated sludge only in the first one.