The native shrub, Piliostigma reticulatum , as an ecological “resource island” for mango trees in the Sahel

•We hypothesize that native shrub+mango intercropping enhances soil properties.•Shrub+mango intercropping significantly increased AMF colonization of mango roots.•Microbial biomass-C was significantly greater in shrub+mango soil treatment types.•Shrub+mango soil treatments showed more diverse soil microbial communities.•Opportunities for shrub intercropping may exist elsewhere but are underutilized.