Abstract:
t Arbuscular mycorrhizal fungi (AMF) are associated with the root system of coffee (Coffea arabica L.)
plants, but their distribution in smallholder agroforestry and
monocultural coffee systems is not well known. This study
investigates the spatial distribution of AMF spores in a field
study in southwestern Ethiopia. Soil samples from different
depths (0–50 cm) were collected under the tree canopies of
Acacia abyssinica, Albizia gummifera, Ficus sur, Ficus
vasta and randomly selected unshaded coffee plants at
different sampling points (canopy base, radius, edge and
outside canopy). Significantly higher AMF spore densities
were recorded at canopy bases and at 0–30 cm soil depth.
Spore populations were found to belong to five genera:
Acaulospora, Entrophospora, Glomus, Gigaspora and
Scutellospora, with Glomus and Acaulospora dominating.
Sampling points, sites and depths, shade tree species and
shade tree/coffee plant age affected AMF spore density.
Agroforestry practices including the use of leguminous
shade trees effectively maintained AMF numbers in soils
even at depth compared with unshaded coffee plants
(monocultures)
