The Changes Of Soil Fertility In Continuous Cropped Tobacco Field And Application Of Microbial Agents

Because of the good geographic conditions and suitable climate, Henan province is an important tobacco planting in China. But in recent years, the area of Henan tobacco planting is reducing, and vega continuous cropping is common, the quality of tobacco is also affected seriously. According to the survey, the nation and the vast majority of areas in Henan province had continuous cropping condition, continuous cropping years from 3 years to 20 years.We have conducted a series of investigation and sample analysis of many cities in Henan province, including the investigation of continuous cropping tobacco in Henan province, and chose some serious areas for field soil sampling analysis on the basis of investigation on the problem of continuous cropping. We can get that, the rule of several kinds of main regional soil enzyme activity change in different continuous cropping years vega is basically consistent, the urease, invertase, acid phosphatase and catalase activity and organic matter in the tobacco soil are continuous cropping increases at first and then increase decreased in Jiaxian and Song County. Enzyme activity of the various trends of Xiangcheng County Soil more tortuous, showing an upward trend in the rise and fall decline, but the overall trend is downward. The changes in microbial communities, the trend in the microbial content of the soil of Jiaxian is basically the same Songxian, the bacterial, yeasts and actinomycetes content changes are first increased and then decline in these two regions, but the microbiological of Xiangcheng County area as the same trend as activity, the trend is not very significant, but ultimately reduced. Content of the mold is connected with the increase for the year to show an upward trend, as the majority of the soil fungal pathogens belong, and the increase in the number of mold is not conducive to the growth of tobacco, so the changes in the number of soil fungi and the quality of soil environment is negatively correlated.Therefore, activity in tobacco and even beneficial bacteria content with increasing continuous cropping increases as a certain number of years, but more than a certain number of years after the presentation is decreased, but the harmful bacteria are the opposite.In case of continuous cropping tobacco field investigation and also carried out pot experiment to suppress continuous cropping. According to the physical of various surveys and harvest growing growth index of soil and chemical properties and microbial content for potted tobacco, final integration of all data that we can get that better is to process 5 and process 10, followed by the T7、T21、T1、T9、T11、T12、T27、T25、T4、T14、T16、T17、T23.