| This topic studied the low temperature degradation bacterium agent straw returned to the changing rule of the black soil nitrogen, carbon, quantity of soil bacteria, fungi, actinomycetes and the influence of soil enzyme urea and hydrogen peroxide enzyme activity; And molecular ecology method is used to analyze the low temperature degradation bacterium agent straw counters-field treatment on the influence of soil bacterial diversity, in order to use low temperature composite microbial agents improve the efficiency of the degradation of corn straw, combined the technology of big ridge deep loose type reamer, the straw returned with complex microbial agents on chernozem soil nitrogen, soil carbon, soil microbes, enzymes, and the influence of the bacterial diversity, in an effort to repair the degradation of black soil fertility, realize resource recycling of straw, protect agricultural ecological environment, promoting the sustainable development of modern agriculture with science and technology support.The main conclusions of the research are as follows:(1) The use of compound bacterium agent at low temperature significantly increased soil total nitrogen and ammonium nitrogen; Compound bacterium agent to deal with the content of nitrate nitrogen in low temperature, highest temperature compound bacterium agent, cellulose decomposing bacteria and cellulose decomposing bacteria at low temperature processing of soil microbial biomass nitrogen content is higher.(2) Application of low temperature compound bacterium agent treatment significantly improved the content of soil organic matter. Soil microbial biomass carbon content peak appeared in filling stage; low temperature bacteria agent of soil microbial biomass carbon content is higher than other processing.(3) After dealing with the low temperature bacteria agent, compared to the three microbial groups, the increase of soil actinomycetes sharpest, actinomyces characterized by dominant, the amount of bacteria is in the middle and the amount of fungi are the last; soil actinomyces and bacteria, fungi are characterized by positive correlation, the correlation efficient was 0.66 and 0.46, respectively, show that in the process of straw returnning, applying inoculants on soil microbial community composition can produce certain effect.(4) Applying low temperature bacteria agent processing soil urease activity was obviously higher than other processing, in addition to the normal temperature bacteria agent compound bacterium handling soil urease activity was slightly higher than controls, biosurfactant treatment and cellulose decomposing bacteria soil urease activity than controls; The processing quantity of soil urease activity and soil fungi are presented a trend of reducing the rise, and reach the highest stage. On the analysis correlation showed that soil urease activity and there is significant positive correlation between the number of soil fungi, correlation coefficient r of 0.65, no significant related to bacteria, actinomyces. The soil catalase activity was higher than control, compound bacterium highest soil catalase activity in low temperature.(5) Biosurfactant treatment at low temperature and room temperature biosurfactant lane belt than other processing belts clearer, many bands for a total of stripe; But there is some characteristic bands that bacteria agent degradation of straw returned different treatment on soil bacteria in the tissue has different degree of influence. In the stage of corn tasseling, diversity index order for the highest cellulose decomposing bacteria treatment at low temperature, low temperature compound bacterium agent to deal with no significant difference compared with controls. And evenness index, the compound bacterium agent treatment is lower than the control treatment at low temperature. DGGE analysis showed that application of compound bacterium agent in low temperature physical distance between treatment and control, to explain the influence of the diversity and distribution of bacteria in the soil. |
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