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.

Light sierozem of the south-east of Kazakhstan are characterized by a low humus content, weak structure and limited moisture capacity, which causes their relatively low level of natural fertility and limits the productivity of agricultural crops. In the context of agricultural intensification, an urgent task is to find environmentally safe and cost-effective ways to increase corn yields for grain. The present study evaluates the effect of organic humic fertilizer Atmas on the growth, development and productivity of corn. It has been established that the use of humic fertilizer stimulates plant development and increases the mobility of nutrients in the rhizosphere. This ensures a more intensive formation of the root system, improves the absorption of macro and microelements and helps to increase the resistance of plants to stress factors of the arid climate. As a result, grain yield increased to 13.2-15.9 t/ha, providing an increase from 4.7 to 26.1% compared with the control. Thus, Atmas organic humic fertilizer is an effective means of increasing corn productivity for grain in light sierozem, ensuring sustainable crop formation, improving the agrochemical properties of the soil and increasing the economic efficiency of crop cultivation.

Spring barley is one of the strategically important grain crops, characterized by high plasticity, early ripening and a wide range of economic applications. The area of spring barley cultivation in Kazakhstan is more than 2 million hectares. The selection and study of the effect of humic fertilizers on the growth and development of spring barley in Bogara conditions is an urgent research task. According to our field and laboratory studies, the use of humic fertilizers has a beneficial effect on the growth and development of spring barley in light gray soils with low availability of humus and mobile macronutrients. Humates activate the microbiota, stabilize soil moisture and increase nutrient absorption. In conditions of drought during the earing and grain filling period, due to a sharp increase in the average daily temperature and a decrease in soil moisture, the effectiveness of humic fertilizers decreases. Humic fertilizers can remain effective under the condition of growing drought-resistant varieties of spring barley with a short growing season (75-80 days) in combination with leaf fertilizers with humates and adapted agricultural techniques, taking into account the long-term agrometeorological forecast.

Seasonal nitrogen dynamics in irrigated sugar beet reflect interacting thermal, soil-water, depth, and fertilization conditions, yet responses of individual N fractions remain insufficiently resolved. A two-year field experiment (2025–2026) examined NH₄⁺-N, NO₃⁻-N, hydrolysable N, and total N in the 0–20 and 20–40 cm layers under mineral NPK and biological amendments, together with microbial indicators, FDA hydrolytic activity, crop growth, and root yield. During April–August 2025, air temperature exceeded the 2000–2024 mean by 2.35 °C, and precipitation was 31.6% lower. However, gravimetric soil moisture increased between spring and summer sampling in both years despite lower pre-sampling rainfall. Over the same sampling periods, 0–20 cm NO₃⁻-N declined by 41.2% in 2025 and 24.8% in 2026, while NH₄⁺-N increased in 2025, resulting in a 7.3% decrease in total mineral N rather than a proportional decline in both mineral fractions. Soil depth significantly affected all N variables, biological amendment affected total N (p = 0.015), and the first two PCA axes explained 64.4% of standardized variance. NPK increased mean root yield by 26.6% (p = 0.001), whereas biological-amendment and interaction effects were non-significant. These findings highlight seasonally and vertically differentiated soil N dynamics under irrigation without establishing rainfall-induced soil drought or a causal temperature effect.