Effect of community-based soil and water conservation practices on arbuscular mycorrhizal fungi types, spore densities, root colonization, and soil nutrients in the northern highlands of Ethiopia

Abstract

BackgroundSoil and water conservation measures (SWC) have a great practical significance to the restoration of arbuscular mycorrhiza (AMF). The objective of this study was to quantify the effect of decades long community-based soil and water conservation practices on arbuscular mycorrhiza fungi spore density, woody plant root colonization, and soil nutrients.MethodsThe SWC measures considered were stone terraces, exclosures + stone terraces, exclosures alone, and adjacent non-conserved open communal grazing lands. Soil and root samples were collected from the rhizosphere of matured woody plant species using systematic sampling from 10 m × 10 m plot based on slope positions. Spores were isolated using wet sieving and decanting method, while AMF fungal root colonization was done using the gridline intersection method.ResultsThe study revealed that five major genera of AMF, including Glomus, Acaulospora, Gigaspora, Scutellospora, and Entrophospora were identified. Glomus was found to be the most abundant genera, which accounted for (52%) of the total spore density, followed by Acaulospora (18%). Besides, exclosures had the highest total spore density (60%) being followed by stone terraces (23%), whereas the lowest (17%) spore density was recorded in the open communal grazing lands. Total root colonization among the treatments ranged from 48.6% in the open communal grazing lands to 68.7% in the exclosure with terraces. Hyphal colonization was higher than arbuscular and vesicular colonization. The total colonization was in the order of exclosure with terraces > exclosure alone > terraces > non-conserved communal grazing lands.ConclusionsRehabilitating the communal grazing lands with terraces and exclosure is an important approach for restoring AMF and regenerating the degraded lands.