International Science and Technology Journal

In modern farming systems, effective fertilization provides plants with nutrients in appropriate quantities, according to plant requirements, which affected by plant age and weather conditions, and creates favorable conditions for developing fruit quality and improving production efficiency. An experiment was performed to determine the changes in the N contents in soil and apple leaves, as well as its correlation coefficients and regression equations on yield parameters, and K, Ca contents in apple fruit. The experiment was conducted over two years (2018 - 2019) on apple trees cv (Cross-validation for choosing Tree complexity). ‘Cultivar ‘Yona Gold’were M9 T337 rootstock, in the experimental orchard located in the fields of Maradik region in Serbia. The three types of fertilizers (ammonium nitrate, monoammonium phosphate, potassium nitrate)that used in this study. Different doses were applied to prepared trees by a drip irrigation system and the traditional method of fertilization. The results concluded that the application of ammonium nitrate led to an even distribution of mineral N forms in the root zone, as well as had not led to a significant increase in the total N in the apple leaf at the first year, but in the second year had a positive impact on the content of N in the leaves. However, the addition of N fertilizer with both ways was negatively affected the Ca content and the K / Ca ratio in apple fruit.