Вплив азотних добрив на продуктивність і якість біомаси деяких сортів енергетичної верби в умовах Західного Полісся України

Abstract

These are the results of research on the influence of nitrogen fertilizers on biomass productivity and biomass qualitative indices of willow energy plantations under conditions of the southern part of Western Polissya, Ukraine. The object of this study were energy plantations of three willow cultivars of Swedish breeding: 'Tora', 'Tordis' and 'Inger', for which the soil ammonium nitrate was added to in the amount of 100, 200, 300, 400 kg / ha . after cutting the bushes; controlled without fertilizers. It is established that fertilizers affect the productivity of the investigated willow cultivars significantly. The yield control of dry biomass of three-year willow energy plantations were Tora 39.8 t / ha, Inger 21.6 t / ha, and Tordis 26.9 t / ha . In terms of fertilization, this indicator of the variety 'Tora' increased with amplifying fertilizer dose to 6.9; 6.2; 4,1 and 1,6 t / ha respectively, in 'Inger' - to 5,9; 6.7; 3.3 and 1.2 t / ha respectively, in 'Tordis' - by 4.6; 4.1; 2.5 and 1.4 t / ha respectively. The three-year willow biomass contains from 1.1 to 1.5% of total nitrogen, from 1.65 to 1.90% of phosphorus and from 1.9 to 2.4% of potassium. Its ash content is 1.2% for Tora and Inger cultivars, and 0.6% for Tordis without applying fertilizers. The index increases with amplifying doses of fertilizers to 2.9% for the Tora, up to 4.0% for 'Inger' and up to 4.1% for 'Tordis'. The biomass calorific value of all cultivars varies insignificantly, from 17.9 to 18.4 MJ / kg in different fertilizer variants. Thus, there is a clear decrease tendency of this index while fertilizer doses are increasing, which is associated with a rise in biomass ash content. The energy output from 1 hectare is quite closely correlated with the fertilization dose for all investigated clones: when the dose is increasing, the energy output is amplified. The most efficient energy output of willow plantation in the three-year crop of biomass is contained in the 'Tora' tree stands - from 729 to 1056 GJ / ha, while this index varies from 395 to 691 GJ / ha for the Inger cultivar, and from 496 to 704 GJ / ha for the Tordis, depending on the fertilizer options. In the interest of increasing productivity of energy plantations in the region of research, it is advisable to apply a dose of 200 kg / ha of ammonium nitrate. Keywords: willow, energy plantation, cultivars 'Tora', 'Tordis' and 'Inger', productivity, ash content, NPK content, biomass calorific value