| Northeastern black soil area is not only an important crop production industry base but also protected resources of China. In recent years, with raising the reclamation area and emerging excessive fertilization problems constantly, has caused the black soil resources decline rapidly. Soil microorganisms depend on the soil ecological environment is an important part of the soil structure. Soil environment is a complex system which determined by the diversity of small regional soil environment and the high soil microbial variability. Land use change influences the factors of microbial community structure directly; microbial community can also indirectly express the soil quality. Because microflora is much less known by people than the animal and plant, basing on the variety of different soil use type, it is difficult to compare soil microorganism community response and variety. The long-term experiment has a contribution to the research of change of microbial community diversity in the same location and soil environment with different soil use types to protect the northeast black earth with providing the theory basis for the sustainable use of resources, according to the actual demand to choose more suitable and more environmental way for using the valuable black soil resources. Moreover this study provides related research on black soil microbial community diversity under different soil utilizations. In this study, basing on the soil microbial dilution plate counting method to measure the microbial quantity, we using Biolog ECO micro plate culture method to investigate the ecological function of the microbial community and its utilization degree of various carbon sources. At this time we adopted the quantitative PCR and 454 pyrosequencing to investigate soil microbial community structure variety in each processing distribution and the change in the microbial community distribution characteristics.With the correlation analysis of the microbial community under different soil us e, the conclusions were as followed:(1) The dilution plate counting method of measurement data analysis as a result showed that the number of cultivable microorganisms and the variety had obvious differences in the different treatment. Leisure soil environment was more suitable for microbial life and cultivation of barren land. The land use change had a big impact on the number of cultivable microorganisms.(2)Bare land microorganisms on carbon source utilization rate was lowest, the largest carbon source used by eight treatments for the microbial community was carbohydrate.(3) Soil microbial quantitative PCR results showed that 16 S bacteria and 16 S archaea biomass changed significantly, and their relationship was mutual inhibition. The amount of 16 S bacteria in treatment Nat was maximum. It was sensitive that ammonia-oxidizing bacteria were applied in the NPK three treatments.(4) 454 pyrosequencing results showed that the soil microbial community categories after the change of soil utilization way were not altered, but there was a quality variation on the category level in different treatments. Heat map analysis results showed that the soil microbial community structure in same location was significantly changed by different soil utilization ways.Therefore, Soil microbial quantity, ecological function and structure of the microbial community in same geographical position of northeast black soil area changed significantly by different soil utilization ways after many years were investigated. Bare land utilization was not conducive to soil microbial life and not be used efficiently. Leisure land utilization could repair the barren soil ground. According to the advantages and disadvantages of land use change in this study, appropriate measures for special condition are adopted to protect the precious northeast black soil resources. |
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