Data from: Active and total rhizosphere microbiomes of plant mixtures diverge from additive expectations, depending on nitrogen and plant composition

In a greenhouse experiment, we tested how monocultures and mixtures of legumes, brassicas, and grasses affect plant traits and the total and active rhizosphere microbiomes under varying nitrogen levels. While shoot biomass was predictable from monocultures, legume-containing mixtures yielded greater-than-expected root biomass and N-fixation.

BONCAT-FACS, coupled with 16S rRNA gene amplicon sequencing, revealed that each plant species supports distinct active and total microbiomes, and nitrogen addition increased divergence among plant species and their mixtures in the total microbiome. In plant mixtures, microbiomes were often additive combinations of those associated with the individual species. However, legume–grass combinations frequently induced non-additive shifts in microbial composition, microbial activity, and the abundance of <i>Rhizobium</i> sp.