Effect of fertilizer application methods and drip irrigation on the productivity of columnar apple plants on sod-podzolic soil

Abstract

The field agrochemical experiment conducted in 2021–2023 was designed to study the influence of drip irrigation and two methods of mineral fertilizer application on the components of productivity of columnar apple plants when grown on cultivated loamy textured sod-podzolic soil in the conditions of Moscow Oblast. Drip irrigation, solid fertilizer application, and fertigation were found to have different eff ects on plant productivity indicators. Th e eff ects largely depend on the cultivar and weather conditions. Drip irrigation in conjunction with solid fertilizers increased plant productivity to the greatest extent. Thus, the ‘Ostankino’ cultivar yielded by up to 2.16 kg/tree more, i. e. the productivity rose by 27.1 % compared to the controls. In the ‘President’ cultivar, yield per tree increased by up to 2.18 kg/tree (by 35.4 % compared to the controls). The irrigated and fertilized variants of the experiment were distinguished by higher vegetation productivity values for the ‘President’ cultivar plants. For this cultivar, the highest total growth rate was in the fertigation-drip irrigation variant with an increase of up to 459.2 cm/tree in 2022. Th e average growth over two years was 16.5% higher than in the control group. In the ‘Ostankino’ cultivar, the total length value of shoot growth during irrigation and solid fertilizer application decreased compared to the control group by up to 245.2 cm/tree. On average, over two years it decreased by 15.7 % compared to the controls. In the fertigation-drip irrigation variant, there was a decrease in the ammonia nitrogen content in the soil compared to the other variants. As a result, the total mineral nitrogen content in the soil layer to a depth of 60 cm was minimal. Th e highest value of ammonium content and total nitrogen in the rhizosphere were observed in the variant with drip irrigation and solid fertilizer application.