Apple tree (Malus domestica Borkh) nitrogen supply optimization by fertigation and bacterial fertilizers

Nitrogen is a special macronutrient as it comes into soil only with rainfall, remains of living organisms and fertilizers. Changes of apple ( Malus domestica Borkh) nitrogen supply faster affect the fruit yield and quality as compared to other nutrients. Our paper it the first multivariate study of soil, leaf and fruit mineral status of apple trees on leached chernozem at different ways and sources of nitrogen supply which shows high environmental safety and efficiency of fertigation. The aim of the research was development of a model for optimal nitrogen provision to improve apple tree yielding and fruit quality. Tests with cv. Zhigulevskoe grafted on rootstock 62-396 were carried out in 2014-2016 in the experimental apple orchard planted in 2007 (Michurin Federal Scientific Centre, Tambov Region) at 4.5½1.0 m planting spacing. Each plot comprised 5 trees; all tests were arranged in triplicate. Obtained data were statistically processed by dispersion, correlation and regression analysis...