APPLICATION OF NITROGEN FERTILIZERS BY FERTIGATION AT SEABUCKTHORN NURSERY

The effect of fertilizers application by the method of fertigation with drip irrigation during seabuckthorn growing in the nursery was estimated. The research has been carried out in the nursery field, in the forest-steppe zone of Altai Krai in 2019-2020. The soil on the experimental plot is gray-forest, reaction of the medium pH 5.8-5.9. The content of nitrate nitrogen was in the range of 7.8-9.8 mg/kg in the control variant; after fertilization, these values rose to 87.9 mg/kg. Nitrate nitrogen was determined by the ion-selective method. The soil at a high level is provided with mobile phosphorus 342-453 mg/kg and potassium 181-355 mg/kg - determined according to Chirikov. The research object – is one-year-old seabuckthorn trees of Altaiskaya cultivar. Urea was applied as nitrogen fertilizer in three rates of the active ingredient (40, 60, and 80 kg/ha). Double superphosphate (30 kg/ha) and potassium chloride (30 kg/ha) were used as the background. The soil moisture level was maintained at 70-80% of the LWC. The effectiveness of fertilizers was assessed by the marketable yield of two-year-old seedlings and their quality indicators. The measurements were carried out in the fall, after excavation. According to the values of the parameters of the aboveground part, the dose of nitrogen fertilizer of 60 kg/ha turned out to be the best option. At the same time, the seedlings had a height of 89.5 cm, the number of branches was 4.4 pcs., The diameter of the trunk was 8.4 cm, which is 15.4 cm, 0.5 pcs. and 1.3 mm above the control. The yield of seedlings of the first commercial grade in the experiment averaged 164 pieces. (82.8%), the maximum is marked on the N60P30K30 variant 190 pcs. (93.8%). Control without the use of fertilizers in all respects is significantly inferior to options with fertilizers. Thus, the use of nitrogen fertilizers has a positive effect on the quality of the seabuckthorn planting material. As a result, the utilization of nitrogen fertilizers has a positive effect on the quality of the seabuckthorn plant material, while higher concentrations become unprofitable compared to low ones due to high costs and insignificant differences in the quality of trees