Abstract: To increase the solubilizing potassium mineral and activating soil potassium, a potassium-solubilizing bacteria NGW1 by screening was obtained, which identified as Bacillus mucilaginosus. As experiment treatments, strain NGW1 and muscovite were applied to tobacoo potting. The maximum colonization number of strain was 5.33×10⁵ CFU/g. After transplanting 60 d, experiment treatments significantly increased the tobacco heigh, maximum leaf length, maximum leaf width, maximum stem girth, and also increased slowly available potassium content and rapidly available potassium. Experiment treatments significantly increased the potassium contents of tobacco leaves. After transplanting 60 d, potassium content of lower leaves was 1.57%, increasing by 9.80% than CK, potassium content of upper and middle leaves was 1.90%, increasing by 27.50% than CK. The above data showed that trial treatment can improve the utilization rate of potassium fertilizer and production, output value of tobacoo leaves.

Key words: potassium-solubilizing bacteria, Bacillus mucilaginosus, isolation, identification, tobacoo, application and evaluation