Microbial consortium increases maize productivity and reduces grain phosphorus concentration under field conditions

Inês Pacheco; Rodolfo Ferreira; Patrícia Correia; Luís Carvalho; Teresa Dias; Cristina Cruz

doi:10.1016/j.sjbs.2020.09.053

Microbial consortium increases maize productivity and reduces grain phosphorus concentration under field conditions

Saudi J Biol Sci. 2021 Jan;28(1):232-237. doi: 10.1016/j.sjbs.2020.09.053. Epub 2020 Oct 8.

Authors

Inês Pacheco¹, Rodolfo Ferreira¹, Patrícia Correia^{1

2}, Luís Carvalho^{1

2}, Teresa Dias¹, Cristina Cruz¹

Affiliations

¹ Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
² Soilvitae Lda., Tec Labs - Centro de Inovação Campus da Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.

Abstract

Background: The use of microbes that improve plant phosphorus (P) use efficiency is an avenue to boost crop yields while alleviating environmental impacts. We tested three microbial inoculants (Rhizoglomus irregulare alone - designated AMF; Pseudomonas putida alone - designated PSB; and R. irregulare and P. putida in consortium - designated AMF+PSB), combined with chemical fertilizers, in an intensive maize agricultural system.

Results: As hypothesized: (i) despite the native soil microbial community and the application of P fertilizer, the microbial inoculants enhanced plant P uptake from the soil by 14-60%, and consequently improved P acquisition efficiency; (ii) PSB and AMF+PSB plants produced ±50% more biomass per unit of P taken up, and consequently enhanced plant internal P use efficiency (i.e. the biomass produced per unit of P); and (iii) the combined inoculation of AMF and PSB provided the best results in terms of productivity and P use efficiency. Further, the microbial inoculants altered P allocation within the plant, reducing grain P concentration.

Conclusion: By testing the microbial inoculants under field conditions, our study clearly shows that the microbial consortium (AMF+PSB) increased maize productivity, and at the same time improved P use efficiency. Further, the use of these microbial inoculants was shown to be compatible with conventional agricultural management practices.

Keywords: Arbuscular mycorrhizal fungi; Grain phytate; Microbial consortium; Phosphate solubilizing bacteria; Phosphorus acquisition efficiency; Plant internal phosphorus use efficiency.