Characterization and classification of agricultural soils of Ajacho Lintala irrigation scheme, Soro district, Hadiya Zone, Southern Ethiopia

Understanding soil types in a specific region is crucial for developing effective approaches to control irrigation water usage and promote sustainable agriculture. This research aimed to characterize and classify the soils of Ajacho Lintala irrigation scheme located in Soro woreda of Southern Ethiopia. Through the analysis of 25 auger observations, 4 pedons, a comprehensive reconnaissance survey, and laboratory analysis, this study examined the morphological, and physicochemical characteristics of the soils in the irrigation. The study identified 16 soil samples from four pedons, consisting of both undisturbed and disturbed soil profiles, which were collected for laboratory analysis. The soils in the research irrigation scheme were classified using the FAO/WRB 2015 classification system. The findings revealed that the texture classes of the study irrigation scheme's soils varied from loam to clay loam for Nitisols, silt loam to clay loam for Luvisols, and clay for Vertisols. Moreover, the available phosphorus, total nitrogen, and organic carbon in the soils were categorized as very low to low range, while cation exchange capacity and basic cations (Ca2+, Mg2+, K+, and Na+) were in the medium to high range. Based on morphological and physicochemical investigations, the soils were classified as Humic Nitisols, Rhodic Luvisols, Haplic Luvisols, and Pellic Vertisols. These classifications align with the equivalent USDA classification of Ultisols (Typic Haplustults), Alfisols (Typic Haplustalfs), and Vertisols (Typic Haplusterts), respectively. To maintain and enhance soil fertility a sustainable soil management system is recommended, which includes practices such as continuous crop cover, mulching, and organic manuring with suitable inorganic fertilizers. Additionally, implementing physical land management measures to control soil erosion in slope areas is crucial.