Arbuscular mycorrhizal fungi community composition, richness and diversity on enset (Ensete ventricosum (Welw.) Cheesman) in Ethiopia is influenced by manure application intensity in low‑input farming systems

Abstract

Aims In low-input agricultural systems, arbuscular mycorrhizal fungi (AMF) play a role in plant nutrition, protection and water use. Evaluating how agricultural practices affect the composition of AMF communities is therefore an important step towards sustainable intensification. We characterized the AMF communities in enset (Ensete ventricosum) roots in smallholder enset-based farming systems in south Ethiopia and assessed the effects of soil fertility management on those communities.

Methods We assessed AMF diversity and community composition in the roots of 181 enset plants from 23 farms by Illumina MiSeq amplicon sequencing. Roots were collected from intensively manured parts of the farms (regular manure application), and from less manured parts of the farms (occasional manure application).

Results AMF communities in both intensively and less manured parts of the farms were comprised primarily by species belonging to Glomeraceae, which accounted for 67% of the total operational taxonomic units recorded. However, unlike Glomeraceae, majority of Acaulosporaceae sequences were recovered from less manured parts of the farms. Intensively manured parts of the farms were associated with higher soil pH, available P, organic carbon, total N and C:N ratio, and with significantly lower AMF richness and diversity. Moreover, unexpectedly organic carbon and total N explained a large part of the variation in AMF community composition compared with available P.

Conclusions Intensive manure applications enhance soil nutrient availability and soil organic carbon but result in lower AMF richness and diversity, and in a shift in AMF community composition. This may promote less mutualistic AMF community.