The effect of increasing rates of mineral fertilizers on the yield and quality parameters of potato tubers

Abstract

The yield and quality parameters of potato tubers of Gala variety were determined in the conditions of the Middle Urals in 2020 and 2022 in long-term stationary experiment after prolonged application of NPK increasing rates (30-60-90-120-150 kg a.i.). The application of NPK by 60 kg a.i./ha and more promoted the potato yield raise by 1.1-1.3 times in 2020 and by 1.3-1.5 times in 2022 compared with the control variant without fertilizers (21.4 and 14.4 t/ha by years, respectively). The lowest dry matter content over the years of research was noted at the maximum dose of N150P150K150 mineral fertilizer in the experiment– 15.6 % in favorable weather conditions of 2020 and 19.4 % in the dry 2022. The starch content in potato tubers did not depend on the dose of applied mineral fertilizers and varied in 2020 in the range from 11.1 to 13.8 %, in 2022 – from 14.4 to 16.3 %. In potato tubers the content of crude protein in the wet mass increased from 1.32 to 1.90 % in 2020 and from 1.80 to 2.65 % in 2022 to the weight of wet mass with an increase in the dose of NPK from 30 to 150 kg/ ha active substance. The sugar content in 2020 was 0.58-0.83 % for natural humidity, in 2022 – 0.23-0.47 %. The fiber content in potato tubers did not depend on the doses of applied mineral fertilizers. The application of increasing doses of NPK did not lead to exceeding the permissible value of the nitrate content in fresh potato. According to a comprehensive assessment of the quality of tubers, potato yield, obtained under given conditions, was suitable for the production of low carbohydrate potato products and for fodder purposes.