POTATO YIELDS AND QUALITY INDICATORS WHEN USING DIFFERENT DOSES AND RATIOS OF MINERAL FERTILIZERS IN THE MIDDLE PRE-URALS

The objective of the study is to determine the effect of different doses and ratios of mineral fertilizers on the yield and quality indicators of potatoes in the Middle Urals. The studies were conducted in 2020 and 2022 on the experimental field of the Perm Scientific Research Institute of Agriculture, a branch of the Perm Federal Research Center of the Ural Branch of the Russian Academy of Sciences, located in the village of Lobanovo, 20 km from Perm. The experimental plot soil is sod-podzolic heavy loam. The experiment was set up according to an abbreviated design of 1/9 of the full factorial experiment (6 × 6 × 6). The study was conducted on the Gala potato variety. The average potato yield over the two years of the study varied from 17.8 t/ha in the variant without fertilizer application to 25.0 t/ha with N150P60K150. The increase in yield was due to the use of nitrogen and potassium fertilizers, which can explain 58 % of the variability in the indicator in the experiment. Under the conditions of the dry growing season of 2022, a decrease in starch content was noted with the use of mineral fertilizers from 17.4 % in the control to 14.1 % with the use of N150P150K150. Under favorable growing conditions in 2020, this pattern was not observed. Dry matter and nitrate nitrogen content in tubers increased with nitrogen fertilizers, while phosphorus and potassium fertilizers reduced these values. Nitrogen content during the flowering phase was below the optimal level, ranging from 2.65 to 3.53 %. Potassium content varied widely, from low to excessive. Phosphorus content was optimal and excessive.