Formation of productivity of willow energy plantations at different levels of soil fertility under conditions of Western Polissia

Abstract

Purpose. To identify ways to increase the productivity of willow plantations on low-productive soils of Western Polissya and to improve the technology of their cultivation.Methods. Field, laboratory, statistical.Results. On dark gray light loamy soil, the highest height of the plants of energetic willow was with a planting density of 20 thousand pcs./ha. The application of mineral fertilizers from the calculation of N60P100K100 contributed to an increase in height by 8 cm, relative to the option without fertilizers (control). An increase in the dose of phosphorus and potassium fertilizers by another 100 kg against the background of N60 ensured an increase in shoots by 32 cm in comparison with the control. With a planting density of 15 thousand pcs./ha, the height of the shoots was slightly less – from 290 cm in the variant without fertilizers to 319 cm in the variants with the introduction of mineral fertilizers. The largest average shoot diameter was in the rarest variants (10 thousand units/ha) – from 14.4 mm, in the variant without fertilizers, to 17.5 mm, in the variant with the introduction of mineral fertilizers at the rate of N60P200K200. Similar data were obtained on sod-podzolic cohesively sandy soil. There were also higher plantations with a planting density of 20 thousand pcs./ha (from 219 cm to 240 cm). On average, over three years of growing willow, the highest yield of dry biomass of 18.2 t/ha was obtained on dark gray light loamy soil with a planting density of 20 thousand pcs./ha and fertilizing at the rate of N60 P200 K200. The application of mineral fertilizers (N60P200K200) on the dark gray light loamy and sod-podzolic cohesive-sandy soil in 2018 ensured an increase in the yield of dry willow mass of energetic by 4.0–5.5 t/ha. Increase in landing density from 10 thousand pcs./ha up to 20 thousand pcs./ha contributed to an increase in the yield of three-year dry willow mass from 11.6–15.6 t/ha to 18.2–23.7 t/ha and from 7.8–10.3 t/ha to 9.8–12,5 t/ha, when grown on dark gray light loam and sod-podzolic beef-edible soil, respectively. Conclusions. During the first three years of growing willow energy plantations in the conditions of West Polesie, the application of mineral fertilizers (N60P200K200) on dark gray light loamy and sod-podzolic cohesive-sandy soil ensured the largest increase in dry crop yield – 4.0–5.5 t/ha and 2.5–2.7 t/ha, respectively. An increase in yield was also facilitated by an increase in planting density from 10 to 20 thousand/ha. The highest yield of dry biomass (18.2 t/ha per year) was obtained on dark gray light loamy soil with the highest planting density (20 thousand units/ha) and a maximum dose of fertilizers (based on N60P200K200).