A phosphocompost amendment enriched with PGPR consortium enhancing plants growth in deficient soil

Abstract

ABSTRACT In the present study, we assessed the agronomic value of a formulated plant growth-promoting rhizobacteria (PGPR) consortium combined with a phosphocompost amendment in deficient soil, using three plant models (Phaseolus vulgaris, Zea mays, and Solanum lycopersicum). PGPR consortium contains four strains which have been identified as Pseudomonas sp. DN 13–01, Sphingobacterium suaedae T47, Bacillus pimilus X22, and Bacillus cereus 263AG5, respectively. They have previously displayed their P solubilizing capacity and to have PGPR traits. In this study, the four strains were able also to dissolve potassium (K), with K solubility (KS) indices range between 0.950.03 and 1.210.25 in solid medium and released K values between 30.251.21 and 45.230.84 g-L−1in liquid medium. The bacterial strains also produced acid and alkaline phosphatases, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, protease, cellulase, pectinase, lipase and amylase enzymes. The amendment of deficient soil with phosphocompost enriched with the PGPR consortium increased much more soil productivity and plant growth compared with controls uninoculated. The formulated PGPR consortium combined with phosphocompost gave the best yield in terms of plant height, number of leaves, number of fruits, shoot biomass, root biomass, and dry shoot biomass of the three-plant studied. Simultaneously, the PGPR consortium inoculation increased P and K uptake in the shoots and available P and K in the soil. In summary, our results showed that the application of PGPR consortium combined with phosphocompost amendment increased plant growth in deficient soil.