α-Fe2O3 nanomaterials strengthened the growth promoting effect of Pseudomonas aurantiaca strain JD37 on alfalfa via enhancing the nutrient interaction of the plant–rhizobacteria symbiont

Plant growth-promoting rhizobacteria (PGPR) are an important supplement for crop production, but their application suffers from unstable efficiency in real soil environments due to the vulnerability of the plant–rhizobacteria symbiont.