This study explored the benefits of organo-mineral fertilization to unlock the full potential of ‘Golden Delicious’ (Malus domestica L. Borkh.) apple cultivation in Southeastern Kazakhstan’s irrigated chestnut soils. The research focused on assessing its effects on tree growth, fruit productivity, and the rhizosphere microbial activity. Field experiments conducted between 2021 and 2025 investigated the effects of various fertilization strategies on 3–4-year-old apple trees grafted on both MM106 and M9 rootstocks. The experimental design included an unfertilized control group, a mineral fertilization treatment (N₉₀P₉₀K₉₀), and several organo-mineral combinations incorporating Agroflorin, Al-Karal, BioSok Energy Plus, and vermicompost. Findings revealed organo-mineral fertilization significantly improved both the yield and quality of apple fruits, alongside enhanced storage performance. Specifically, the apple fruit yield saw a substantial increase of 39%–64% over the control group. Furthermore, soluble sugar and dry matter content rose by up to 1.9% and 1.5%, respectively. In light chestnut soils, a combination of vermicompost and BioSok Energy Plus fertilization delivered exceptional results for apple production. This treatment achieved the highest fruit yield, reaching 29.5 t per hectare, and remarkably extended shelf life to a full six months. Beyond these direct benefits, the fertilization also fostered a healthier soil environment by considerably increasing Azotobacter and Pseudomonas populations in the rhizosphere. This indicates a more robust nutrient cycle and heightened soil biological activity, confirming organo-mineral fertilization as a highly effective and sustainable strategy.

Keywords: Apple (M. domestica L.), Golden Delicious, organo-mineral fertilization, apple productivity, rhizosphere microorganisms, soil-plant interaction, fruit quality

Key findings: This research demonstrated organo-mineral fertilization significantly enhances apple (M. domestica L.) fruit yield. Yields increased by an impressive 39%–64% compared with the unfertilized control. The optimal fertilization strategy for maximizing fruit productivity involved combining NPK with vermicompost and BioSok Energy Plus.