Civil and Environmental Research www.iiste.org ISSN 2224-5790 (Paper) ISSN 2225-0514 (Online) Vol.16, No.1, 2024 1 A Comprehensive Review on Gypsisols: Characteristics, Genesis, and Environmental Implications Asmamaw Ketema Gizaw College of Agriculture and Natural Resources, Soil Resource and Watershed Management Department, Assosa University, PO box 18, Assosa, Ethiopia * E-mail of the corresponding author: asmamawketema@gmail.com Abstract Gypsisols, a distinct soil order recognized by the presence of gypsum as a primary soil-forming mineral, play a crucial role in shaping terrestrial ecosystems and influencing environmental processes. This research review provides a comprehensive examination of Gypsisols, encompassing their key characteristics, genesis, and the broader environmental implications associated with their presence. The paper delves into the unique physicochemical properties of Gypsisols, exploring the impact of gypsum on soil structure, fertility, and water retention. The genesis of Gypsisols is explored, considering factors such as climate, parent material, and biological processes that contribute to the formation of these specialized soils. Additionally, the review investigates the distribution of Gypsisols globally, highlighting regions where they are prevalent and the ecological significance of their presence. Keywords: Gypsisols, Genesis, Characteristics, Distribution DOI: 10.7176/CER/16-1-01 Publication date: January 31 st 2024 1. Introduction Soil classification is one of the most important stages in natural resources assessment. There are a number of theoretical soil forming processes that determine the prevailing soil types. Soil patterns can be understood using soil-landscape models that provide a key to establish or predict soil type occurrences using different soil environmental attributes (Vargas and Alim, 2007). In other words, each soil formation factor, i.e. geology, geomorphology (landform, exposure and elevation), vegetation, land use and time, determines the different stages and paths of soil development. Moreover, soil classification can present a basis for soil-related agro-technology transfer (Braimoh, 2002; Buol and Denton, 1984). According to Shi et al. (2005), systematic soil classification connects research findings and their useful extension to field applications. The significance of soil classification and mapping as a foundation for agricultural planning and the adoption of environmentally friendly land use techniques. There is no single system for classifying soils that is approved worldwide yet. However, the Soil Taxonomy (ST, Soil Survey Staff, 1992) and the World Reference Base for Soil Resources (FAO/ISRIC/ISSS, 1998) are more commonly used on a global scale (Shi et al., 2005). Weathering forces act on parent material that has been deposited by geologic agencies to create soil (Jenny, 1941). There are five main factors that affect the type of soil that develops. They include the type of parent material, the environment in which it has existed, the presence of organisms, the terrain, and the amount of time that the forces of soil formation have had an impact on the parent material (Brady and Weil, 1999). By its very nature, soil development involves a complex process of weathering that affects the content of one or more components in a specific horizon (Breemen and Buuman, 2002). The factors that make up soil are interdependent; one affects the others' effects in different ways. Each of the aforementioned factors has an impact on how a soil develops, however depending on the location; one factor may be dominant and account for the majority of the soil's features. In some locations, a change in any one of the five criteria causes the creation of a different type of soil. Gypsisols are soils with significant secondary gypsum buildup. These soils are located in the driest regions of the arid climate zone, which helps to explain why many of them were classified by the leading soil classification systems as desert soils (in the former Soviet Union) and yermosols or xerosols (FAO–UNESCO, 1971–1981). They are referred to as Gypsids by the US Soil Taxonomy. (WRB, 2006) This review was aimed to investigate and understand the genesis and mineralogy, characteristics, geographical distribution and management of Gypsisols. History, connotation and correlation The name Gypsisol comes from L. gypsum and refers to soils with substantial accumulation of calcium sulphate. In the FAO 1974 legend of the Soil Map of the World, Gypsisols were classified under the Yermosols and under the Xerosols. As of 1988 Gypsisols were taken up to the highest hierarchical level in the FAO Legend. In Soil Taxonomy, Gypsisols key out under the Aridisols as Gypsiorthids. In the USSR Gypsisols were called Desert soils. Common soil units: