Actuality of theme. Due to the critical dependence of Ukraine on energy imports and the exhaustion of traditional fuels, the need to find an alternative solution to the energy problem is becoming extremely important. One of the important areas of obtaining own resources of energy raw materials is the accelerated cultivation of plant biomass, in particular - wood. One of the ways of mass production of wood energy biomass is its cultivation on energy plantations of willow. The success of this direction of energy biomass in certain soil and climatic conditions, in particular in Kyiv Polissya, depends on the use of the most productive and resistant to negative factors of a particular area species and varieties of willow and a system of effective elements of their cultivation technology.
Scientific novelty of the obtained results. For the first time on the basis of complex researches the types and grades of a willow suitable for cultivation on marginal lands of the Kyiv Polissya are selected; the close dependence of edaphic conditions and certain agro-technical measures on the growth and productivity of willow energy plantations has been established. The technology of creation and cultivation of energy willow plantations in the research region has been improved with the establishment of the optimal periodicity of energy biomass harvesting. Scientific provisions on the energy intensity of energy willow plantations in the marginal lands of Polissya depending on soil conditions have been further developed.
Of the two variants of floodplain soils in Polissya of Ukraine, are more suitable for growing energy biomass is sandy soil than peat-swamp. Willow energy plantations have a larger leaf surface area (from 22.0 to 31.3 thousand m2 / ha), higher photosynthetic potential (3.56–5.06 million m2 ∙ days / ha) and net photosynthesis productivity. up to 1.62 g / m2 per day), which provides relatively high productivity (0.77–2.21 t / ha / year). To create energy willow plantations on peat-swamp soils, it is advisable to use the variety 'Zbruch', which has the highest biomass productivity (3.28 t / ha / year), while in the variety 'Ternopilska' this figure was 1.10 tons / ha / year, and in the clone of willow - 0.77 t / ha / year. After the first three years of growing willow energy biomass on peat-swamp soil, losses ranged from 25.92 to 39.15 thousand UAH / ha, on sod-podzolic cohesive sandy soil - also, but less. Also economically unprofitable was the application of mineral fertilizers in dark gray loamy soil, while without the application of fertilizers received a profit of 5.04 thousand UAH / ha for planting densities 10 thousand / ha, 8.19 thousand UAH / ha - for planting 15 thousand / ha and 12.64 thousand UAH / ha - for planting 20 thousand cuttings per 1 ha. Fertilization has reduced the cost-effectiveness of growing willow energy biomass due to today's high fertilizer prices. The calculation of energy efficiency showed that the cultivation of willow bioenergy raw materials is quite efficient. Even on the least productive peat-swamp soil, the energy efficiency coefficient was higher than one. On sod-podzolic cohesive sandy soil, quite close indicators of the energy efficiency coefficient were obtained - from 5.71 to 7.63. These indicators were even higher for the cultivation of willow biomass on dark gray loamy soil - from 12.08 in the version without mineral fertilizers and at a density of 15 thousand / ha to 14.68 - for the maximum dose of fertilizer and maximum planting density (20 thousand cuttings per 1 ha).
Key words: energy plantations, Salix viminalis L., Salix triandra L., varieties, soil conditions, planting density, biomass productivity; leaf surface area, photosynthetic potential, economic and energy efficiency.
