Calcium in the “soil-plant” system of apple orchard when using nitrogen and potash fertilizers

The experiment was carried out to study the relationship between soil calcium conditions and content of this element in fruit leaves apple trees at ground fertilization with nitrogen potassium. experimental orchard is located forest-steppe zone Central Russian Upland (Oryol region). Loamy haplic luvisol a slightly acidic reaction high organic matter. Fruit plantations are represented by ‘Sinap orlovsky’ variety on rootstock 54-118 planted 2013. Ammonium nitrate potassium chloride were used as fertilizers applied early spring doses N30K40, N60K80 N90K120. Annually from 2016 2019, exchangeable water-soluble Ca compounds total fruits determined. With annual application potash changes tree nutrition occured already first years after treatments. lay increasing mobility subsequent decrease element’s concentration root zone. At same time, there an status fruits. positively correlated exchange (r = 0.43; P<0.05) 0.51; P<0.01) forms element. There no statistically significant studied leaves.