Co-Inoculation of Mesorhizobium ciceri with Either Bacillus sp. or Enterobacter aerogenes on Chickpea Improves Growth and Productivity in Phosphate-Deficient Soils in Dry Areas of a Mediterranean Region

Biological nitrogen fixation requires a large amount of phosphorus (P). However, most of
the soils are P-deficient and the extensive use of P- chemical fertilizers constitute a serious threat
to the environment. In this context, two field experiments were carried out to investigate the effect
of co-inoculation of Mesorhizobium ciceri with phosphate solubilizing bacteria (PSB), Bacillus sp.,
and Enterobacter aerogenes, on chickpea as an alternative to chemical nitrogen (N) and phosphorous
fertilizers in P-deficient soils in dry areas of Morocco. The results revealed that combined inoculation
of chickpea with rhizobia and PSB showed a significant enhancement of chickpea nodulation, biomass
production, yields and N, P, and protein content in grains as compared to single inoculation or single
application of N or P. A significantly higher increase was obtained by inoculating chickpea with
Mesorhizobium sp. MA72 combined with E. aerogenes P1S6. This combination allowed an enhancement
of more than 270% in nodulation, 192% in shoot dry weight and 242% in grain yield. The effect of this
combination was equivalent to the effect of combined application of N and P fertilizers. Formulation
of biofertilizers based on tasted strains could be used for chickpea co-inoculation in P-deficient soils
for an eco-friendly sustainable production of chickpea.