Influence of soil depth and tillage methods for potatoes in the mountainous zone of the Republic of North Ossetia-Alania

The depth and methods of soil tillage for potatoes are crucial agrotechnical practices that can increase tuber yield without significant additional costs. This study aims to investigate the impact of soil tillage depth and methods, in combination with mineral fertilizers, on potato tuber yield. The study was carried out in the mountain-meadow subalpine zone of the Dargavskaya Basin in RSO-Alania, located on the northern slope of the Central Caucasus between the Rocky and Bokovy ridges, at an altitude of 1450 m (Dargavs village). The climate of the Dargavskaya Basin is relatively mild and temperate. The soil of the experimental plot is mountain-meadow subalpine, leached with humus-illuvial horizon loamy on clay shale eluvium. During the years of research, the meteorological conditions were noted as contrasting. The temperature conditions in spring were relatively favorable, but during the flowering phase, there was a decrease in air humidity and an increase in air and soil temperature. The Farn variety of potatoes was planted in the first decade of May and harvested in the second decade of September. No-tillage methods of soil cultivation have been compared to moldboard tillage, and it has been found that they do not significantly affect soil moistening, accumulation of available nutrients, yield, or quality. However, weediness increases. When plowing mountain chernozems of RNO-Alania, it is recommended to not exceed a depth of 25 cm. Increasing the depth of plowing to 35 cm or reducing it to 15 cm can cause a decrease in soil tillage yield with a flat tiller. When moldboard plowing to a depth of 25 cm, economic efficiency resulted in a profit of 283,1 thousand rubles from sales per hectare. However, increasing the plowing depth to 35 cm reduced the profit to 56,1 thousand rubles, while reducing it to 15 cm resulted in a profit of only 52,2 thousand rubles. The economic profitability levels were 141,4%; 165,7% and 147,2%, respectively. When applying fertilizers at a dose of N60P60K60 and cultivating the soil with a flat tiller at a depth of 25 cm, the profit was 247,1 thousand rubles per hectare with an economic profitability of 152,2%.