Regulation Of Organic Fertilization Patterns On The Soil Microflora Of Tobacco Topsoil

Deterioration of soil quality of tobacco, declining of fertility, reducing microbial diversity, aggravation of soil-borne diseases and concentration of harmful substances limit the formation of leaf quality style and sustainable and healthy development of tobacco leaf. However, improvement of soil, strengthen of soil fertility and construction of the "soil-microorganisms-root" as the core of efficient health tobacco microcosms were one of the fundamental way to solve this problem. In this experiment, the organic cultivation model as the starting point, systematically studied the impact of the law of different C/N ratio of organic fertilizer input on components of organic carbon and nitrogen, microbial flora, soil nutrition, and agronomic traits and yield and quality of tobacco in tobacco field. The main findings were as follows:1. Dynamic change of components and proportion of organic carbon, nitrogen in soil,organic carbon in soil was an important factor in regulating the level of soil fertility and soil micro-ecological balance, fertilizing mode of organic fertilization pattern significantly increased TOC, DOC of soil in growth periods and DON and TON in the late of tobacco growth, and it also had a significant impact to improve EOOC content at the early and late in soil. Each treatment of organic fertilization pattern reduced the EOOC/TOC ratio of the soil overall indifferent growing periods, significantly increased the ratio of DOC/DON and TOC/TON in soil, increased the stability of organic carbon, contributed to the accumulation of soil organic carbon and nitrogen, and improved carbon balance and characteristics in soil. And the dynamic changes of components and ratios of organic carbon in the soil were consistent with the law of soil nutrient supplying high-quality tobacco, and it could help to establish fertility patterns of high quality tobacco, treatment effects on YJ4and YJ3were particularly significant.2. Microbial and enzyme activity were the most sensitive indicators to reflect the quality and fertility of soil micro level. Each pattern of fertilization on organic fertilization pattern significantly increased the number and diversity of bacteria, fungi and actinomycetes in soil in each of period, significantly increased the activity of urease, pHospHatase and invertase in soil at thevigorous stage and topping stage, improved metabolism and supply level about carbon, nitrogen and pHospHorus. During different growth periods of tobacco, each treatment of organic fertilization pattern improved catalase activity compared with the CG pattern, that showed CK>YJ>CG. Catalase activity in soil was increased first and then decreased with the improvement of C/N in organic fertilizer. This showed that the improvement of soil organic nutrients, organic fertilizer properly adjusted C/N can improve soil fertility and biological activity and improve the soil’s ability to remove harmful free radicals, and it was conducive to the sustained and healthy development of micro-ecological improvement in tobacco fields,and YJ4was the best.3. YJ fertilization pattern significantly reduced the pH of topsoil, the basic performance was CK>CG>YJ, and pH of the soil decreased with the increasing of C/N in the treatment. The peak of the available nitrogen, ammonium nitrogen and nitrate content in soil was later than CG pattern, pHospHorus and potassium content in soil of each treatment basically showed a bimodal curve with the growth of the advance, and the first peak occurred during the vigorous stage, the second peak about pHospHorus content of YJ was earlier than CG but later than the effective K. Available nitrogen, pHospHorus and potassium content in soil in YJ pattern were significantly lower than that in CG pattern at the rosette stage and vigorous stage, and higher at topping stage and early of harvest stage. Nitrogen supply was more stable in YJ pattern, and the supply capacity of soil available K was strong in the late, it was more conducive to the growth and quality formation of the middle and upper leaves of tobacco plants,YJ4and YJ3were the best.4. Root architecture and the total number of tips per plant roots, the total number of branches, root volume, total root length and total root surface area in YJ pattern were significantly higher than CK at the rosette stage, vigorous stage and harvest stage, which YJ4and YJ3pattern were significantly higher than CG pattern. Improving C/N of fertilizer significantly improved agronomic traits of tobacco plants, and it had a greater impact on stem girth, leaf width, YJ4and YJ3pattern significantly increased basal stem girth and leaf width of tobacco.5. Reducing sugar, total sugar and potassium content in the upper and middle leaf tobacco in YJ pattern were significantly higher than that in CG pattern, however, the content of nicotine and chlorine significantly lower than CG and CK. Reducing sugar, total sugar and potassium content in the upper and middle leaf tobacco in YJ pattern were increased first and then decreased with the increasing of C/N in the treatment, YJ4and YJ3pattern were the highest; the content of nicotine and chlorine in the upper and middle leaf tobacco in YJ pattern first decreased and then increased with the increasing of C/N, YJ4was the lowest, and then YJ3. YJ pattern significantly increased the content of Fe, Mg, Zn and P of tobacco, decreased the content of Cu, YJ4and YJ3were the best. There were no significant differences in the total output and total output value between YJ4and CG, and the rest of treatments in YJ pattern were significantly lower than CG, but significantly increased the proportion of fine tobacco and significantly reduced the proportion of cigarette smoke and moderate inferior than CG, YJ4and YJ3were the best.6. The study revealed that the fertilizing mode of organic fertilization pattern improved C/N of fertilizer, significantly improved pHysical and chemical properties and microbial environment of soil, it was conducive to the growth of soil fertility and tobacco roots, improved agronomic traits and quality of tobacco leaf, adjusted the distribution of tobacco class, and improved the output value of the land.