## 1 Introduction  
According to FAO data, approximately 1.5 billion hectares of soil worldwide are suitable for agriculture [1]. Neutral and slightly alkaline soils in subtropical zones with dry climates comprise 8177.1 thousand hectares or 5.46% of the total land area globally. Additionally, 14.5 million square kilometers, or 11% of the world's land area, is suitable for agricultural production. Over the last 50 years, the area of irrigated land has increased by nearly 12%, resulting in a 2.5- to 3-fold increase in agricultural production [1; 2]. Consequently, the study of theoretical bases for improving soil-ecological and energy states and increasing the fertility of neutral and weakly alkaline soils, considering the agrogenic and post-agrogenic evolution of virgin and irrigated lands, as well as the development of theoretical and practical aspects of their enhancement, is of significant importance [3; 4]. Food security issues are prominent both globally and in Central Asia, where population growth and diminishing agro-productive resources are critical concerns. This is further aggravated by irrigation water scarcity and challenges in water management. In this context, the Fergana Valley serves as a highly informative site for soil and agroecological research. Transboundary and geopolitical risks to food security are pronounced here, as the valley spans parts of Uzbekistan, Tajikistan, and Kyrgyzstan. The Fergana Valley and the Zeravshan oasis are pivotal Central Asian regions within the post-Soviet space responsible for food security. In contrast, Uzbekistan's vast desert and semi-desert areas are underutilized due to moisture deficits. In the Fergana Valley, more readily available water resources have led to the expansion of farming into the adyr zone, previously deemed unsuitable for agriculture, and even into the Yazvan sand massif, where unique landscapes and fauna are being compromised for rice cultivation [3; 4; 5]. At present, many scientific studies are devoted to the problems of sustainable development of the Fergana Valley. Some studies are focused on the problems of water resources and changes in their quality in the process of agro-industrial development of the region [3; 4]. The influence of irrigation on soil quality under cultivation of different crops (cotton, wheat, barley, etc.) was studied [5]. The relationship between irrigation and drainage water composition and their influence on chemical properties of soils in the Fergana Valley were studied with the example of hydromorphic and other soils [6; 7; 8]. Earlier, it was also shown that long-term irrigation leads to overconsolidation of soils and formation of pedolitic (petrocalcic) soil layers, which leads to changes in biochemical properties of soils in the context of crop cultivation [9; 10]. The parent materials of the Fergana Valley include loess rocks, alluvial layered rocks, proluvial pebble deposits, and sands of various origins. Despite sands occupying a smaller area, overgrazing has led to significant wind erosion problems [11]. Historically, the Andijan district had over-moistered soils typical of swampy conditions before intensive drainage efforts in the 20 th century [12]. Under the direct influence of anthropogenic factors, the soils of the central Fergana desert zone, which began to be intensively developed from the 1930s to the 1950s, have undergone significant changes. Notable transformations have occurred in their morphology, agrochemical parameters, and salt composition. Calcisols, a crucial component of the soil cover in the Fergana Valley, have particularly been affected. Following their cultivation and incorporation into agricultural practices, several issues emerged, especially concerning the impact of irrigation on farming and the quality of agricultural products [6; 9; 10]. Therefore, the study of modern agrochemical, agrophysical, and in particular biogeochemical energy states of soils and their fertility (of uncultivated and irrigated Calcisols) of the northern Fergana Valley faces numerous difficulties.