Comprehensive assessment and information database on saline and waterlogged soils in Kazakhstan: Insights from Remote Sensing Technology

Soil salinity and waterlogging are significant challenges in agricultural regions worldwide, including Kazakhstan. Understanding the characteristics and distribution of saline and waterlogged soils is crucial for developing effective strategies to mitigate their negative impact on crop productivity and environmental sustainability. This study aims to provide a comprehensive assessment of saline and waterlogged soils in various zones of the Republic of Kazakhstan, including the desert, foothill semi-desert (vertical), semi-desert (latitudinal), and dry-steppe areas. By examining the genetic horizons, chemical composition, ionic composition, salt content, and granulometric composition of these soils, this research contributes to the knowledge base necessary for implementing targeted soil management practices and restoration techniques. Fieldwork was conducted at 66 designated base points, where detailed descriptions of the genetic horizons of these soils were made. The data collected from these surveys were utilized to create an extensive information database, encompassing various indicators such as nomenclature, profile structure morphology, chemical composition, ionic composition of water extracts, salt content, absorbed cations, and granulometric composition. The findings reveal that saline soils cover a significant area of 16.7% (35,817.4 thousand hectares) of the agricultural land, while waterlogged soils occupy 0.5% (1,083.4 thousand hectares). The study highlights the poor fertility of saline soils due to high concentrations of water-soluble salts, predominantly sodium chlorides and sulfates, throughout the soil profile. Conversely, waterlogged soils exhibit distinct features such as gleyed horizons and a greenish-grayish color, with variations in fertility. The information presented in this study contributes to the understanding of the characteristics and distribution of saline and waterlogged soils in Kazakhstan, facilitating the development of strategies to restore soil fertility and implement appropriate management practices.