Reaction of different potato varieties to natural fertility and fertilizers during cultivation on meadow-chernozem soil in the conditions of the Omsk Irtysh Area
Potatoes are among the most valuable crops of high productivity with high requirements for mineral nutrition. The article presents material on the study of the reaction of potato varieties (Alaya Zarya, Svitanok Kievsky, Kormilets, Zekura and Rozara) on soil fertility and fertilizers. Field experiments were carried out in 2008-2010 on the experimental field of Omsk State Agrarian University. The two-factor experiment was repeated three times. The planted scheme was as follows: 70 x 30 cm tubers weighing 80-100 g. The experimental plot size is 9.6 m<sup>2</sup>, the total test plot territory is 510 m<sup>2</sup>. Varietal agrochemistry was clearly shown in the responsiveness of potato varieties to the use of mineral fertilizers. As a result of research, it was established that the yield of potatoes cultivated without the use of fertilizers increases as follows: Zekura (21.0 t/ha) < Rozara (21.1 t/ha) < Svitanok Kievsky (22.8 t/ha) < Kormilets (23.4 t/ha) < Alaya Zarya (25.4 t/ha). The reaction of potato varieties to the use of fertilizers (yield increases, t/ha) is as follows: Alaya Zarya (8.2 t/ha) > Svitanok Kievsky (7.0 t/ha) > Zekura (4.8 t/ha) > Rozara (4.6 t/ha) > Kormilets (3.3 t/ha). The average yield of tubers of non-fertilized varieties was lower by 24.7% if compared to the fertilized option. The highest payback characterized the variety Alaya Zarya (60.0 kg per ha), the lowest characterized the variety Kormilets (30.0 kg per ha). The Svitanok Kievsky, Alaya Zarya and Kormilets varieties had the highest coefficients of using soil nutrition elements (CUN) and performance indicators of nitrogen fertilizers (PIF). When cultivating these varieties in conditions of artificially created fertility, a tendency towards an increase in the content of dry matter and starch in tubers can be observed. During the experiments the bioenergetic feasibility of using calculated doses of mineral fertilizers when cultivating different potato varieties on meadow-chernozem soil was established. Thus, the conducted research confirmed the possibility of purposeful impact on the growth, development and yield of potato plants due to the correct choice of varieties and use of fertilizers in doses with proven effectiveness.