ASSESSMENT OF THE CONDITION AND MORPHOLOGICAL FEATURES OF SOILS IN THE HEADWATERS OF THE VELYKYI KUYALNYK RIVER

Problem Statement and Purpose. The upper basin of the Velykyi Kuyalnyk River is highly sensitive to soil degradation processes caused by both natural conditions and intensive agricultural use. Erosion, structural disturbance, and moisture imbalance are exacerbated by climatic shifts and anthropogenic pressure. A field study conducted in October 2024 by the Department of Geography of Ukraine, Soil Science and Land Cadastre at Odesa I. I. Mechnikov National University aimed to assess the current state of soils in this region. The study focused on describing soil morphology, sampling for laboratory analysis, and classifying soils using both the national system and the WRB approach to better understand transformation drivers under changing environmental conditions. Data & Methods. Despite sufficient study of the natural resource potential of the Velykyi Kuyalnyk basin, detailed soil investigations remain fragmented. Previous research in the region highlighted the need for a deeper analysis of soils and their transformation processes. Soil studies in the Velykyi Kuyalnyk River basin and Kuyalnytskyi estuary were carried out by leading regional specialists, focusing on ecological and economic assessments, degradation analysis, and the creation of modern soil maps. Based on these works, updated cartographic representations were developed using data from earlier surveys and regional monitoring. Significant contributions have also been made by researchers from the Odesa State Agrarian University, particularly V. I. Mykhailiuk and H. B. Moroz, who investigated pedoecotonal transitions under mesoarid moisture conditions over the past two decades. In recent decades, scholars from the Faculty of Geology and Geography at Odesa I. I. Mechnikov National University conducted targeted research into soil morphogenetic characteristics, considering geomorphological positions and land use. However, most studies focused on the southern part of the basin, making our research in the headwaters particularly relevant. Results. The results of soil research conducted in the upper basin of the Velykyi Kuyalnyk River indicate the predominance of chernozem soils with high humus content, well-developed structural composition, and the presence of carbonates, all of which contribute to their high natural fertility. However, signs of gleying were observed in several soil profiles, suggesting periodic overmoistening. This negatively affects soil aeration and limits the availability of nutrients for plant uptake. Intensive land use, the construction of hydraulic infrastructure, and other human activities have led to increased soil erosion, a decline in water-holding capacity, and disruption of soil structure. These degradation processes are further exacerbated by climate change – rising temperatures, decreased precipitation, and increased aridity – posing significant risks to the stability of agroecosystems in the region. To stabilize the soil cover, an integrated set of measures must be implemented. These include contour farming practices, the establishment of protective shelterbelts, the transition to organic agriculture, and the reclamation of degraded lands. Equally important is the optimization of the river’s hydrological regime to support ecological balance. Thus, long-term ecological sustainability and the effective use of land resources in the Velykyi Kuyalnyk River basin depend on the adoption of a comprehensive approach that combines soil conservation, climate adaptation, and the development of ecologically sound agricultural systems.