The impact of apple plantings fertigation on the seasonal dynamics and distribution of the nutrients in soil

Abstract. The fertigation of fruit plantings exercises has significant influence on the change in the nutrients supply of soils, in the places of fertilizers localization first of all. For the purpose of this research the seasonal dynamics and regularities of the nutrients distribution in soil, when applying fertigation systemically in apple plantings, will be established. It were fruit plantings to establish the clearly defined seasonal dynamics of the change in nitrate nitrogen content: the higher concentration in the zone of the local fertilizer distribution, when applying regularly the fertigation, and partial removal of unassimilated nitrogen in the winter and spring period on abundant rainfall. The ammonium nitrogen content was highly changeable and weakly dependent on the zone of soil sampling. The statistically significant high correlation of increase in the content of available phosphorus (r = 0.95) and exchangeable potassium (r = 0.81) in soil immediately under the drippers was brought to light. The high level of these nutrients content maintains for a long stretch of time and is not limited to a single vegetation period. The varying degree of the nutrients migration, when applying fertigation of apple plantings, was established. The distribution of available phosphorus was fixed to a greater extent in vertical direction, particularly immediately under the drippers, and that of exchangeable potassium in horizontal one. The gained knowledge permits to improve the methods for evaluation of the nutrients supply of soils to devise the optimal mineral fertilization patterns when applying fertigation of fruit plantings