Intercropping, the simultaneous cultivation of multiple crops in the same field, holds potential for enhancing plant nutrition and crop yield. This study investigates the role of root-associated microbiota in iron nutrition within a peanut/maize intercropping system. Through microbiome profiling, strain and substance isolation, and functional validation, the researchers discovered that intercropping boosts iron nutrition in peanuts but not maize, accompanied by microbiome convergence between the two plants. A *Pseudomonas* -secreted siderophore, pyoverdine, was identified as a key factor improving iron nutrition in both greenhouse and field experiments, highlighting the significant role of siderophore-secreting *Pseudomonas* in the intercropped system's improved iron nutrition. These findings suggest avenues for developing intercropping practices aimed at enhancing plant nutrition.