One of the ways of improving the physicochemical properties of replanted soil is to use fertilisers containing humic acids. The aim of the study was to analyse the impact of soil activator H-850 WG on the yield and quality of apples of the Najdared cultivar harvested in conditions of replantation. Between 2015 and 2017 an experiment was carried out on replanted and crop rotation soils. The replanted soil came from an orchard where apple trees had grown for several dozen years and they had been replanted several times. At the crop rotation site in the apple orchard there was a ten-year cultivation break, during which plants exhibiting the phytosanitary effect were grown (wheat, rape and charlock). A soil activator containing more than 60% of humic acids was used on both soil types. The following parameters were analysed in the experiment: the yield volume, fruit quality (average weight, extract content, fruit firmness and acidity level), the leaf surface and the content of chloroplast pigments in it. The results of the three-year research showed that the previous soil use method influenced the yield, the leaf assimilation area and the quality parameters of apples. The parameters analysed in the study were significantly worse on the replanted soil. The treatment of the soil with the activator containing humic acids resulted in a greater yield and better qualitative parameters of apples – increase the average fruit weight, extract content and fruit firmness. The soil activator exhibited higher efficiency on the replanted soil than on the crop rotation soil.

26.2.2021