Impact of Plant Growth Promoting Rhizobacteria on Different Forms of Soil Potassium under Wheat Cultivation.

This study aimed to investigate the effect of some plant growth promoting rhizobacteria with potassium dissolution ability on different forms of potassium in soil under the cultivation of wheat. The factorial experiment was conducted as a randomized complete design with three replications in greenhouse conditions. The treatments consisted of bacterium inoculation (without inoculation, Enterobacter cloacae Rhizo_33, Pseudomonas sp. Rhizo_9, consortium of Enterobacter cloacae Rhizo_33 and Pseudomonas sp. Rhizo_9), potassium application (2.87 mg K kg-1 of soil and without potassium application).The results indicated that soils treated with Enterobacter cloacae Rhizo_33, either receiving potassium or not, maintain a higher amount of exchangeable K (337mg kg-1 ) and water soluble K (1.25 and 1.31 meq L-1 with and without K application, respectively). The non-exchangeable K and nitric acid-extractable K values were decreased by inoculating bacterial strains. The grain yield was significantly enhanced by the inoculation of bacterial strains irrespective of rates of potassium application. About 19.16% increase of grain yield was recorded by inoculation of Enterobacter cloacae Rhizo_33 and without potassium application. A significantly greater amount of K uptake in grain was obtained in soils treated with Enterobacter cloacae Rhizo_33, with and without the application of potassium (28.7 and 30.7 mg pot-1 , respectively). There was a significant (P<0.01) and positive correlation between grain yield and grain, shoot and root K uptake. Potassium uptake had a positive significant correlation with water-soluble K and exchangeable K; it was negatively correlated with K (HNO3 ). The data suggested that inoculation of soil with mentioned bacteria can improve plant growth and potassium uptake. This article is protected by copyright. All rights reserved.