| The screened rhizobacteria strains were used to make the plant growth-promoting rhizobacteria (PGPR) bio-fertilizers, and then their quality was detected using the plateform. Their effects on highland barley (Hordeum vulgare L. var. nudum) were studied through pot experiments in greenhouse and field experiments in the alpine pastoral region. The 15N analyzer (NOI7) was used with the method of 15N isotope dilution to determine the nitrogen-fixing ability of the bio-fertilizer. The results are as follows:1. The quality detection of the bio-fertilizers showed that the quantity of the plant growth-promoting rhizobacteria in bio-fertilizers, including the solid nitrogen fixating bio-fertilizer, solid phosphate solubilizing bio-fertilizer, solid compound bio-fertilizer, liquid nitrogen fixating bio-fertilizer, liquid phosphate solubilizing bio-fertilizer, liquid compound bio-fertilizer, was still over 108/g after stored for 30, 60, 90, 120 days at room temperature. It decreased down to 106/g when stored for 150 days and then it dropped rapidly with contamination. This suggested that the expiration of the bio-fertilizer should not more than 120 days.2. The result of pot experiments in the greenhouse showed that the growth stage of highland barley was 4 to 10 days ahead of time by applying the nitrogen fixing bio-fertilizer. And the plant height was increased by 33.78% to 40.46%, the total phytomass was increased by 83.50% to 86.98% compared with the control. The half amount of applied chemical nitrogen fertilizer could be replaced by the nitrogen fixation bio-fertilizer regarding some of the growth characteristics. The peat was the proper carrier for bio-fertilizer making because its nitrogen-fixing amount (4.1 mg/plant) was greater than that with liquid carrier (2.3 mg/plant).3. The result of the field experiment showed that the nitrogen-fixing bio-fertilizer performed better in early growth stage of highland barley and the aboveground...
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