Abou-Zeid, M.Y. ( 2011). Improvement Of Soybean Growth By Co-Inoculation With Rhizobium And Plant Growth-Promoting RhizobacteriaEgypt . J. of Appl. Sci., 26 (11) 2011 445-459
Abstract: Two-field experiments were carried out at Nubaria Agricultural Research Station, ARC. in the summer seasons of 2008 and 2009; consecutively to study the response of soybean cultivar Giza 111, inoculated with Bradyrhizobium japonicum, to different rates of phosphorus fertilizer in the presence of Bacillus polymyxa, Bacillus megatherium or a mixture of both to throw more lights on the role of these microorganisms in increasing enzymatic activity in soil after 75 days of sowing and in increasing soybean yield and N, P and K seeds contents under the calcareous soil conditions. Regarding the effect of inoculation and phosphorus fertilizer on dehydrogenase activity (DHA) of rhizosphere soil, results indicated that inoculation with both bacteria led to a significant increase in DHA in the tested season. With respect to nitrogenase activity of nodules and rhizosphere and nodules weight, data show that the inoculation increased significantly nitrogenase activity (N2-ase) in both seasons, while it led to a significant increase in nodules weight of the 2nd season. Results showed also that inoculation of soybean seeds with a mixture of both bacteria plus 30 kg P2O5/fed gave the highest significant grain yield, 100-seeds weight, protein yield which increased by 14.1, 11.98 and 32.60 % over uninoculated control. Also the same treatment increased significantly N, P, and K contents of soybean seeds in both tested seasons over uninoculated treatments. Consequently, results revealed that inoculation of soybean seeds with B. polymyxa combined with 30 kg P2O5/fed produced significantly the highest oil yield ( 13.42 % %) as compared to uninoculated treatment. It can be concluded that inoculation of soybean seeds with (Bradyrhizobium japonicum and a mixture of B. megatherium, B. polymyxa) and application of 30 kg P2O5/fed can improve soybean yield and its quality under calcareous soil conditions.
Keywords: (Phosphate dissolving bacteria, B. megatherium, B. polymyxa, nitrogenase, dehydrogenase, seeds yield, N, P and K, inoculation, soybean.)
