Arbuscular mycorrhizae fungi diversity and population as affected by watershed management practices at Kara Soditti Watershed, Wenago district, Southern Ethiopia

Land degradation is among a serious ecological problem that results in decreased land productivity, including soil nutrients and microbiota. Soil and water conservation (SWC) practices such as micro‐basin, Fanyaa juu, and soil bund construction are widely implemented to combat this degradation by reducing erosion and retaining water at Kara Soditti Watershed, and their impact is typically assessed using only physical or chemical (soil nutrient levels) indicators. This approach overlooks the biological restoration of the soil. Therefore, this study was designed to evaluate the impact of SWC practices on the arbuscular mycorrhizal fungi (AMF) diversity at Kara Soditti Watershed, Wenago district. A total of 36 soil samples were purposely collected from three conservation practices (micro‐basin, soil bund, and Fanyaa juu on three topographic levels (upland, midland, and foot slope sites) with control. The AMF spore densities of rhizosphere varied from 9 ± 0.42 to 163 ± 7.7/15 g soils. The percentages of AMF root colonization varied from 18.9% to 91.3%. The isolated and identified AMF spores included genera Glomus ( n = 218, 48.77%), Acaulospora ( n = 123, 27.52%), Gigaspora ( n = 61, 13.65%), and Scutellospora ( n = 45, 10.07%). The genus Glomus ( n = 6) contained the highest number of species followed by Acaulospora ( n = 5), Gigaspora ( n = 3), and Scutellospora ( n = 3). The evaluation of soil management practices showed a clear hierarchy of effectiveness; soil bund (most effective), followed by micro‐basin, then Fanyaa juu, with control sample being the least effective. Consequently, soil bund can be considered the optimal practice for improving the measured soil indicators. Generally, the outcomes showed that SWC practices can restore and increase AMF spore density, variety, and root colonization, as well as soil physicochemical properties. Hence, SWC practice should be practiced in the study area and the whole country to restore and enhance soil microbiota and physicochemical qualities.