In the conditions of southeastern Kazakhstan, which is characterized by an arid climate and the need for irrigation, the use of organic biologically active preparations in horticulture represents a promising direction. This article presents the results of a study on the effects of the preparations Agroflorin, Al Karal, and Biosok Energy Plus on the biometric indicators of the Golden Delicious apple variety. Special attention is paid to the development of shoot length, branch diameter, leaf surface area, and other morphological traits of the plants. The scientific novelty of this research lies in the development of a technology for the application of organic fertilizers and biopreparations that enhance the activity of soil microorganisms. These microorganisms regulate biological processes in the soil and improve the nutrient uptake of plant root systems. Experimental studies conducted under the conditions of irrigated light chestnut soils of southeastern Kazakhstan revealed that organic fertilizers and biopreparations, particularly "BioSok Energy Plus", Agroflorin, and Alkaral, stimulate the vital activity of beneficial soil microorganisms and improve plant nutrition. Soil microorganisms play a key role in mineralizing organic substances and synthesizing their cellular proteins by utilizing carbon and nitrogen. Microbial groups such as actinomycetes, mold fungi, and bacteria contribute to the replenishment of nitrogen in the soil by decomposing organic matter. As a nitrogen source, they primarily require easily soluble nitrogen compounds, which are provided through the application of organic fertilizers and biopreparations. The study established a positive effect of organic fertilizers, particularly BioSok Energy Plus and Agroflorin, on the population of ammonifying bacteria, pseudomonads, amylolytic bacteria, and micromycete flora in apple orchard soils. This, in turn, enhances the nutrition of the root system and improves the overall physiological condition of apple trees.