Are native phosphate-solubilizing bacteria a relevant alternative to mineral fertilizations for crops? Part II: PSB inoculation enables a halving of P input and improves the microbial community in the rapeseed rhizosphere

In this study, three PSB strains belonging to the Pseudomonas genus, isolated from soil harvested under rapeseed (Pnapus), winter pea ( Pisum sativum , Ppea), and faba bean Vicia Pfaba), were tested on growth. This test was performed in a greenhouse experiment with four plant replicates pots per modality during vegetative stage of (10 weeks), combination gradient P fertilization (P100, P50, P25 P0 corresponding 125, 62.5, 31.5 0 mg 2 O 5 plant, respectively). Contrasted results observed for strains. (Pnapus) showed no effect biomass or status. Ppea Pfaba increased amount roots when decreased 50%, but (Ppea) dramatically below input threshold. For at P50 strains, an increase alkaline phosphatase activity concomitantly rhizosphere . The structure diversity microbial community then assessed explore possible indirect effects application. Relative abundance several bacterial genera potentially involved biological control against phytopathogens Sphingomonas Acidobacteria Gp6, Lysobacter Thermomonas genus Spartobacteria class), whereas relative other nitrogen sulphur cycles Ramlibacter, Nocardioides Inhella, Bradyrhizobium Thiobacillus ), possibly sustaining even more access essential nutrients. • Solubilizing Bacteria screened crops strain Faba (F23) allowed 50% decrease fertilization. F23 inoculation surrounding roots. Effects growth could also result induced shifts community.