Productivity and quality of paulownia wood in the Right Bank Forest Steppe of Ukraine

Abstract

Purpose. To determine the effect of application of fertilizer, cryoprotectant and foliar feeding on the formation of yield and quality of paulownia. Methods. The research was conducted in 2021–2023 at the experimental plot of the Bila Tserkva National Agrarian University located in the forest plantations in the Right Bank Forest Steppe of Ukraine (Kyiv region). Design of the experiment: factor A – fertilization: 1) without fertilizers, 2) application of organic fertilizer Vermykompost before planting (400 kg/ha); factor B – application of cryoprotectant: 1) without cryoprotectant, 2) cryoprotectant Mars-EL (0.5 l/ha) applied at the beginning of leaf growth; factor B – foliar application of fertilizers: 1) no treatment, 2) Quantum-AmiNoFrost (1.5 l/ha), 3) SmartGrow Recovery (2.0 l/ha). Results. At the end of the first, second and third years of paulownia cultivation, the average diameter of the trunk was 8.8; 12.2 and 17.3 cm, respectively. The application of organic fertilizer contributed to the average annual increase in this indicator by 3.0, 1.5, and 1.7 cm, and application of cryoprotector – by 0.3, 0.3, and 0.4 cm per year, respectively. The highest values of the trunk diameter in the experiment were obtained under combined application of Vermykompost, cryoprotectant and foliar fertilizer Quantum-AmiNoFrost or SmartGrow Recovery: in the first year – 10.5–10.6 cm, in the second – 13.1–13.2 cm, and in the third year – 18.4 cm. During the first, second and third years of vegetation, dry matter content of paulownia biomass per plant averaged to 3.0, 12.9, and 26.7 kg, respectively. At the same time, the application of fertilizer provided an increase in the dry matter content of 0.7, 1.7, and 3.8 kg per plant, while application of cryoprotectant provided 0.3, 0.6 and 1.2 kg per plant, respectively. Similarly to the diameter of the trunk, dry matter accumulation per plant was the highest under combined action of all factors of the experiment: in the first year – 3.58–3.60 kg, in the second – 14.1–14.2 kg, and in the third – 29.4 kg. Conclusions. The yield of dry matter of paulownia in the first year of cultivation averaged 1.88 t/ha. Application of fertilizer provided dry matter increase of 0.45 t/ha, and cryoprotectant – 0.19 t/ha in the first year; 8.04 t/ha in the second year, with increases by factors of 0.45 and 0.19 t/ha, respectively, and in the third year – 16.68 t/ha, with increases by factors of 2.40 and 0.73 t/ha, respectively. In all years of the experiment, the highest dry matter yield was recorded in the combined treatment with the use of organic fertilizer, cryoprotectant and foliar fertilization: in the first year, dry matter yield was 2.24–2.25 t/ha, in the second 8.80–8.90 t/ha, and in the third year 18.40 t/ha. The average content of cellulose in paulownia biomass over the years of research was 43.8% and lignin – 20.3%. The use of organic fertilizer provided an increase in these indicators by 1.05 and 0.29%, respectively, and cryoprotectant – by 0.41 and 0.24%. The highest content of cellulose (44.5%) and lignin (20.7%) were noted for the combined action of all three factors of the experiment. As to the ash content, the average indicator for the experiment was 1.1%, and the deviations of his parameter did not depend on the influence of the experimental factors (the difference was within the experimental error).