Desertification and land degradation are common processes in arid and semi-arid regions of Kazakhstan, especially southern parts, where areas are covered by a great variety of desert types. In deserts, soil-forming processes take place in conditions of severe water shortage, and high level of soil degradation and desertification. The main natural factors for these processes are a flat terrain, a high degree of arid climate, soil salinity, carbonate content, a lack of structure and low natural soil fertility. However, the anthropogenic factors of desertification and soil degradation became dominant last decades. The study considers the actual problems of natural and anthropogenic factors of desertification and land degradation within Kazakhstan. The desertification of huge territories is accompanied by soil contamination, waterlogging by surface water and groundwater, soil salinization, erosion (water, wind), degradation of vegetation cover, dehumidification and a decrease in general regional biological capacity. Analysis of the current status of the soil cover has shown intensive land degradation 43 % of the territory of Kazakhstan is subjected to degradation in significant degree; over 14 % of pastures have reached an extreme degree of degradation or are completely degradated. The Aral Sea region, Northern Caspian Sea and Southern Balkhash deserts can be observed as areas of intensive soil desertification, salinization and deflation processes. As well as the desertification process are progressing in the irrigated soils of the deltas of Syrdarya, Shu, Ile and Karatal rivers.

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.

На высохшем дне Аральского моря происходят своеобразные процессы почвообразования. В первую очередь приморские почвы, развитие которых протекает по зональному пустынному типу. Общей закономерностью является слабое развитие процессов почвообразования на фоне сильного исходного засоления и карбонатности. В результате проведенных полевых исследований определены основные типы почв и их морфологические, химические свойства, содержание тяжелых металлов (валовый и подвижный) и специфические черты засоления почв северо-восточного Приаралья. Определены следующие типы почв: солончак обыкновенный, солончак такыровидный и отакыренный, солончак луговой, солончак приморской, песок пустынный, бурая пустынная незасоленная почва. Проведена сравнительная оценка изменения почв Восточного Приаралья в результате обсыхания Аральского моря. Ведущий фактор формирования и развития почвенного покрова на обнажившихся поверхностях морского дна – пустынный климат, определяющий после отступления моря развитие процесса засоления с последующей быстрой аридизацией территории.

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.