Growth promotion of chickpea and barley by a phosphate solubilizing strain of Mesorhizobium mediterraneum under growth chamber conditions

The efficacy of a strain of Mesorhizobium mediterraneum to enhance the growth and phosphorous content in chickpea and barley plants was assessed in a soil with and without the addition of phospates in a growth chamber. The results obtained show that the strain PECA21 was able to mobilize phosphorous efficiently in both plants when tricalcium phosphate was added to the soil. In barley and chickpea growing in soils treated with insoluble phosphates and inoculated with strain PECA21 the phosphorous content was significantly increased in a 100 and 125%, respectively. Also, the dry matter, nitrogen, potassium, calcium and magnesium content in both plants was significantly increased in inoculated soil added with insoluble phosphate. These results show that the inoculation of a soil with rhizobia should not be based only on the effectiveness of the strains with respect to their nitrogen fixation potential, since these microorganisms can increase the growth of plants by means of other mechanisms, for example the phosphate solubilization.