Effect of fertigation on yield and fruit quality of apple (Malus domesticaBorkh.) in high-density orchards on chernozems in Central Russia

Abstract

The research was conducted in 2013-2015 in the experimental apple orchard of I.V. Michurin Federal Research Centre (Tambov region, Russia) with 'Zhigulevskoe' apple trees on B396 rootstock. The aim was to determine the optimal rates of nutrients by fertigation and foliar feeding efficiency. The soil was a leached meadow chernozem, low of humus, heavy loamy on sand with pseudofiber. There were recorded yield, main nutrient content in leaves and soil, as well as the humus content and soil pH, ascorbic acid, sugars and organic acids content in fruits. We applied N(10)P(10)K(10), N(20)P(15)K(20), N(25)P(20)K(25), N(25)P(20)K(30), N(30)P(25)K(30), N(35)P(25)K(35) rates (data are in kg ha(-1) of individual nutrient). Optimal fertigation rate for regions of the Central Chernozem Zone determined in our research was (in kg ha(-1)) N=25, P=20 and K=30. Excessive application of fertilizers through fertigation and also irrigation may led to soil degradation and deterioration of soil fertility, resulting in change of some physical and chemical parameters. The fertilizer rate determined during our research did not significant influence on the soil pH, humus content and cation exchange capacity. The content of ascorbic acid, sugars and titric acids of fruits at harvest was largely determined by the weather conditions of the growing year. Combination of fertigation and foliar fertilizing increased the productivity of apple trees.