Influence des microorganismes solubilisant le phosphate sur la croissance du soja (Glycine max L.).

Abstract

Face to the problem of soil infertility that concern Cameroonian agriculture, the use of phosphate solubilizing microorganisms is an agronomic alternative, economic and environmentally friendly. Microorganisms were tested in plates and in shaking cultures to assess their ability to solubilize rock phosphates from different origins. They were subsequently tested in greenhouse to evaluate their ability to promote the soybeans growth. The results on plates showed that six strains variously solubilized rock phosphates from Algeria, Cameroon, Mali, Morocco and Mexico with index of solubilization (IS) of 2.46 for Galactomyces sp.; 2.34 for Plantibacter sp., 1.99 for Sphingobacterium sp., 1.35 for Enterobacter sp.2, 1.21 for Enterobacter sp.144 and 0.54 for Bacillus sp.. In shaking cultures, they were also able to mobilize variable amounts of phosphorus from rocks, with concentration of 405.47 mg/L, 392.19 mg/L, 329 mg/L, 323.46 mg/L, 260.19 mg/L and 216.56 mg/L respectively for Enterobacter sp.2, Sphingobacterium sp., Enterobacter sp.144, Galactomyces sp.31F, Plantibacter sp., and Bacillus sp..Among the inoculated treatments, the AB (Enterobacter sp.2-Enterobacter sp.144) consortium shows the highest total dry mass (3.28g) compared to the negative control. The results of the different tests suggest that those strains can be an important tool to improve the agricultural production of soyabean.