IMPACT OF LAND USE TYPE ON THE DIVERSTY AND ABUNDANCE OF ARBUSCULAR MYCORRHIZAL FUNGI IN LOKA ABYA, SIDAMA REGIONAL STATE, ETHIOPIA

Abstract

Arbuscular mycorrhizal fungi play a crucial role in plant health by enhancing nutrient uptake, improving soil structure, and supporting ecosystem stability.This study investigates the role of AMF in the soil-plant interactions across different land-use types in Loka Abaya Woreda, Sidama Region, Ethiopia.The study examines the influence of soil physicochemical properties and plant species diversity on AMF distribution, spore density, and root colonization in agroforestry, natural forests, and cash crop systems.Soil characteristics, including pH, nitrogen, phosphorus, organic carbon, electrical conductivity, and texture, were analyzed across four land-use systems: agroforest, natural forest, cash crop, and grassland, revealing significant variation among different plant species. The soils were slightly acidic to neutral, with pH values ranging from 5.73 to 7.56 and phosphorus concentrations varying from 0.0100 mg/g to 0.3120 mg/g. Plant diversity was assessed using random sampling, resulting in the collection of 414 soil samples. Root colonization rates varied significantly, with Citrus sinensis exhibiting the highest colonization in field soil (94.5%), while Ehretia cymosa Thonn and Euphorbia abyssinica showed lower rates. In natural forests, Lennea schimper had 100% colonization, while Dodonaea angustifolia L.f. exhibited the lowest (84%). AMF colonization and spore densities were generally higher in trap cultures compared to field soils, with the highest spore densities in Psidium guajava (2251 spores/100 g) and Balanites aegyptiaca (1228 spores/100 g). Cash crops like Coffee arabica showed 100% AMF colonization and the highest spore density (838 spores/100 g in field soil). AMF analysis was conducted using Pearson's correlation, with data processed using SPSS software version 24.The study identified 30 AMF morphospecies from eight genera, with five genera Glomus, Acaulospora, Claroideoglomus, Enterophospora, and Rhizophagus intraradices showing significantly higher spore production, contributing 43.50%, 32.33%, 8.46%, 4.23%, and 3.62% of the total spore count, respectively. Notably, no single AMF species dominated across all land-use types, but four species Glomus sp.2, Claroideoglomus sp.1, Glomus mosseae, and Acaulospora sp.2 were commonly found, highlighting their ecological significance. The study found a positive correlation between spore density, root colonization, organic carbon, and nitrogen levels, while high phosphorus and soil pH negatively impacted AMF abundance. These findings emphasize the importance of agroforestry and natural forests in maintaining AMF diversity and enhancing soil health. The study recommends further research into AMF dynamics, particularly across different seasons and with molecular techniques, to enhance the understanding and application of AMF in agricultural systems.