The Locust Nitrogenase Hydrogen Rhizosphere Soil Microbial

The soil erosion in the Loess Plateau leading to ecological fragility causes serious harm. The protection forest system proved can certificate sustainable development in the ecologically fragile areas. This research collected locust tree rhizosphere soil sample which has nodules from the artificial locust tree forest in the Loess Plateau. Simulated the process that nodule nitrogen fixation releasing the hydrogen, we use the principle that electrolysis of water produces hydrogen gas processed the soil samples.30 days later, we analyze the impact of rhizosphere microorganisms. This research provides experimental data for the hydrogen produced during nitrogen-fixation which influences the rhizosphere soil micro-environmental, and shows the growth-promoting mechanism.Microorganisms in rhizosphere is a huge system, which interaction and influences the plant growth. Identification of rhizobia and vesicalar-arbuscular, we found that Mesorhizobium in the Robinia Pseudoacacia. VA fungal spores were Glomus and Acaulospora. the number of hydrogen-oxidizing bacteria increases in the processed soil accounting for one third of the total soil microorganisms, which changed the soil microbial community structure of the original. We pick out the advantages of plant growth promoting strains, observate its cell physiological do biochemical tests, sequencing 16S rDNA and eventually identified it as Bacillus cereus Frankland. Found the growth-promoting mechanism is that the strain produces a large number of 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase which inhibition ethylene production.In the processed soil, microbial metabolism intensity, soil dehydrogenase, catalase, urease, invertase, organic matter, auxin and gibberellin were increased. However, it has no phosphate-dissolving effect. These changes in soil constituents may be related to changes in soil microbial communities. Compared with the original soil samples, the experiments of microbial genetic diversity demonstrated that microbial richness significantly increased in hydrogen enrichment.