EFFECTIVENESS OF APPLICATION OF UREA AMMONIUM NITRATE ON SPRING BARLEY CROPS IN THE CONDITIONS OF THE WESTERN FOREST-STEP OF UKRAINE

The results of research on the study of the regularities of spring barley productivity formation at different levels of nitrogen fertilization by foliar application of a Urea Ammonium Nitrate on darkgray podzolized soil of the Western Forest-Steppe are presented. The research was conducted during 2023-2024 at the experimental field of the Department of Agrochemistry and Soil Science of the Lviv National University of Veterinary Medicine and Biotechnology named after S. Z. Gzhytskyi. The experiment was set up according to the scheme, which included options for single and double fertilization of plants with UAN-26: 1. Without fertilizers (control), 2. N30, 3. N60, 4. N80, 5. N15 + N15, 6. N30 + N30, 7. N40 + N40. The application of nitrogen fertilization was carried out on the background of pre-sowing fertilizer application at the rate of P40K40. The effectiveness of double fertilization of crops with UAN at the rate of N40 in the BBCH 13 phase (three leaves) and N40 in the BBCH 37 phase the appearance of a flag leaf) was established, which was manifested in the formation of maximum indicators of spring barley yield structure elements and grain yield. At this level of fertilization, the length of the ear was 11.0 cm, the number of grains in the ear was 21.4 grains/ear, the weight of 1000 grains was 45.9 g. The crop yield was obtained at the level of 5.83 t/ha, which exceeds the unfertilized option by 1.45 t/ha, or 33.1%. As a result of applying different nitrogen rates in the form of a Urea Ammonium Nitrate, no phytotoxicity was detected on spring barley plants.