Аңдатпа
This study evaluated the effects of mineral fertilizers and biological products on the agrochemical properties of light chestnut soil and the productivity of spring barley under rainfed conditions in the Zhetysu Region, Kazakhstan. The objective was to assess the effects of different fertilization systems on soil agrochemical properties, plant growth, and grain yield of spring barley. The field experiment was conducted with three replicates using a mineral fertilizer background of N 60 P 90 K 80 and four biological products - BioEcoGum, BIOGRANO forte, BioAzoPhashit, and BioPhos - applied either alone or in combination with mineral fertilizers. Soil total humus, nitrate nitrogen, easily hydrolysable nitrogen, available phosphorus, exchangeable potassium, carbonates, and soil reaction were determined, along with plant growth parameters and grain yield. Fertilizer application had no substantial effect on total humus content or soil reaction but was associated with changes in the concentrations of available nutrients. The highest nitrate nitrogen (24.0 mg/kg) and available phosphorus (26.5 mg/kg) contents were recorded with N 60 P 90 K 80 + BioAzoPhashit. The greatest plant height (51.3±1.1 cm) was observed with N 60 P 90 K 80 + BioEcoGum. The highest grain yield (1.13 t/ha) and a statistically significant yield increase over the untreated control (0.33 t/ha, or 41.2%) were obtained with N 60 P 90 K 80 + BIOGRANO forte. When applied alone, the biological products produced grain yields ranging from 0.887 to 0.956 t/ha, with yield increases over the control not exceeding the least significant d ifference. Statistical analysis confirmed a significant effect of mineral fertilization on spring barley grain yield, whereas no significant additional effect of the biological products applied in combination with mineral fertilizers was detected.