Influence of mineral fertilizers on potash nutrition and productivity of columnar apple

Abstract

The columnar form of apple tree is promising for growing in super-intensive orchards. The mineral nutrition study of apple tree with columnar crown is relevant due to high density of tree planting. The article presents the study results on the effect of mineral fertilizers on potash nutrition and the yield of columnar apple tree. The experiments were carried out in an experimental orchard located in the forest-steppe zone of the Central Russian Upland (Oryol region). The soil of the orchard is loamy haplic Luvisol with a high content of organic matter. Fruit plantations are represented by columnar apple trees of Poezia variety on 62-396 rootstock planted in 2016. Urea ((NH2)2CO) and potassium sulfate (K2 SO4) were used as fertilizers in doses of N60K80; N90K120; N120K160 which were introduced in early spring. The content of exchange potassium in the soil was determined annually in layers (0-20 cm and 20-40 cm), the concentration of potassium in leaves and fruits, yield. The use of fertilizers contributed to an increase in the exchange potassium content in the soil both in the 0-20 cm layer (45 - 53%) and in the 20-40 cm layer (18-31%). The amount of potassium in leaves and fruits also increased. However, potassium concentration in the leaves (0.77 … 0.95% dry matter) remained significantly below the optimum (1.5% dry matter). A significant increase in the average fruit weight was revealed in options N90K120 and N120K160.