Fig. 4

Bulk soil pH (a) and rhizosphere soil pH (b) as a function of P doses (biochar enriched with Bayóvar rock phosphate) and phosphate-solubilizing bacterial inoculation. Two asterisks indicate significant at p < 0.05. ns, no significant. Uppercase letters compare strains within each P dose and lowercase letters compare P doses within each strain by the Scott–Knott test (p < 0.05). Means and standard deviations of four replications. TSP = 200 mg P of triple superphosphate kg^-1 soil