Growing willow energy in Ukraine is suitable for low-agricultural land. A promising trend of growth productivity planting of willow energy is the use of sewage sludge. This is solving of two problems – providing renewable energy resources and utilization of sewage sludge as a source of pollution.

Sewage sludge is characterized by a high content of basic agrochemical characteristics of natural humus compounds, it can be used as traditional organic fertilizers. The composting of sewage sludge with organic and mineral materials is an effective way to improve the sanitary condition and obtain high quality agrochemical fertilizer.

The purpose of research was to study the characteristics of growth, development and performance of willow energy plants with different sewage sludge application rates and composting on their basis.

To evaluate the growth, development and productivity of willow energy at different rates of sewage sludge application as fertilizer, we have incorporated a field experiment, comprising ten choices of 3 reps. The scheme of planting 0.33 m X 0.70 m. Variants of the experiment: 1. Control – no fertilizer; 2. Fertilizers – N₁₀₀P₁₀₀K₁₀₀; 3. SALT – 40 t/ha, 4. SALT – 60 t/ha; 5. SALT - 80 t/ha; 6. Compost SALT + sawdust (3 : 1) – 60 t/ha; 7. Compost SALT + straw (3 : 1) – 20 t/ha; 8. Compost SALT + straw (3 : 1) – 40 t/ha; 9. Compost SALT + straw (3:1) – 60 t/ha; 10. Compost SALT + straw (3 : 1) + cement dust 10 % – 40 t/ha.

Willow saplings propagate vegetatively and are about 20 – 25 cm long and 0.8 – 1.8 cm thick. Cuttings should be at least 5 dormant, clean and healthy buds. The top of the cuttings need to be treated with paint, with the addition of antifungal agents. They must be planted in the ground in early spring as soon as the stable frost stopped. Before planting seedlings must be soaked in water for 24 – 48 hours, that helps to adapt the temperature and it must absorb such a quantity of water, through which the willow is able to grow without watering several weeks after planting in the ground.

After 1.5 - 2 weeks after planting in the ground, there are first sprouts of the buds and intensive growth of vegetative shoots begins. Even in the early stages of their regrowth we noted a positive trend of growth in ways which have made composts of sewage sludge with straw at a rate of 40 – 60 t/ha.

These results for the three years of research are the highest rates of shoot length variants which were 6 and 10. Both of these options were more intensive in development of the main shoot from the first days after landing, so we can say that the dynamics of growth depends on the background of power plant and the nutrients in the soil.

Further studies were performed to determine the vegetative mass of plants. For our study were selected the freshly cut shoots of plants in the second and third year of vegetation. They were weighed and dried to constant weight. The most productive option for the release of dry energy willow biomass were options 5 and 6, which brought SALT normally 80 t/ha compost from SALT + sawdust (3 : 1) 60 t/ha, respectively. In version 5 content of dry biomass 29.0 t/ha, and moisture content 29.4 %. In accordance to variant 6 content of dry biomass willow 33.7 t/ha, and moisture content - 17.6 %. However, in terms of productivity, this option is highest.

Growth dynamics, development and accumulation of plant biomass willow intertwined with the supply energy background. Making compost from sewage sludge at the rate of 60 t/ha promotes vigorous plant growth from 291 cm to 432 cm and the dynamics of growth of willow biomass energy to 33.6 t/ha compared with other options, which brought fresh sewage sludge to a rate of 40 – 80 t/ha.

Key words: willow energy, biomass, sewage sludge compost.