【作者】 杨双剑；

【导师】 杜相革；

【作者基本信息】 中国农业大学 ， 植物检疫与生态农业健康， 2014， 博士

【摘要】 植烟土壤质量恶化、肥力下降、土壤微生物多样性减少、土传病害加重及有害物质富集是制约烟叶质量风格形成和可持续健康发展的重要瓶颈。而改良土壤、培肥地力,构建以“土壤-微生物-根系”为核心的高效健康的烟田微生态系统是解决这一问题的根本途径之一。本试验以有机栽培模式为出发点,系统研究了不同C/N比有机肥输入对烟田土壤有机碳氮组分、微生物区系、土壤营养和烟株农艺性状及产质的影响规律。主要研究结果如下：1.土壤中的有机碳、氮组分及其比值的动态变化是调节土壤肥力高低及土壤微生态平衡的重要因素,有机施肥模式显著提高了烟株生长各期土壤中TOC、DOC及烟株生长中后期土壤DON和TON含量,对提高前期和中后期土壤EOOC含量也具有显著的作用,有机各施肥模式总体上降低了生育各期土壤中EOOC/TOC比值,显著提高了土壤中DOC/DON和TOC/TON的比值,增加了有机碳的稳定性,有利于土壤有机碳、氮的积累,改善了土壤碳氮平衡及土壤理化性状,且土壤中有机碳、氮组分及其比值的动态变化与优质烟叶土壤养分供应规律基本一致,有助于建立优质有机烟叶培肥模式,其中有机施肥模式YJ4、YJ3作用尤其显著。2.土壤微生物及酶活性是反映土壤微生态质量及肥力高低的最灵敏的指标。有机各施腮模式可以显著增加烟草生长各期耕层土壤的细菌、真菌、放线菌数量及其结构多样性,尤其对生防菌、丛枝菌根及解磷菌等有益菌群有明显促进效应。有机各施肥模式显著提高旺长期和圆顶期土壤中脲酶、磷酸酶和蔗糖酶活性,改善土壤中碳、氮、磷的代谢及供应水平。在烟株生长各期有机各施肥模式较常规施肥模式更有助于提高土壤中过氧化氢酶活性,即表现为CK(不施肥)>YJ(有机施肥模式)>CG(常规施肥模式),且有机各施肥模式间土壤过氧化氢酶活性基本随有机肥中C/N比的提高呈先降低后增加再降低趋势。这说明改善土壤有机营养、适当调整有机肥C/N比,可以在改善土壤肥力及生物活性的同时,提高烟田土壤中有害自由基的清除能力,有利于烟田微生态的改善及烟田的持续健康发展,以YJ4处理最佳。3.有机施肥模式显著降低了耕层土壤的pH值,基本表现为CK>CG>YJ,且有机各施肥模式间土壤pH值基本随有机肥中C/N比的增加而降低。有机各施肥模式土壤中有效氮、铵态氮及硝态氮含量高峰期较常规施肥模式推迟,各处理土壤中有效磷和钾的含量随生育期的推进基本呈双峰曲线变化,第一个高峰均出现在旺长期,有机施肥模式第二个高峰有效磷含量较常规施肥模式提前而有效钾则延迟。在团棵期和旺长期有机各施肥模式土壤有效氮、磷、钾含量均显著低于CG施肥模式,而圆顶期、采收初期则显著高于常规施肥模式,有机各施肥模式氮素营养供应更加稳定,且生长中后期土壤有效钾供应能力较强,更有利于烟株中上部叶片的生长、开片与品质形成,尤以YJ4、YJ3处理最佳。4.在团棵期、旺长期和采收Ⅰ期,有机各施肥模式的根系构型及每株根系总根尖数、总分枝数、根系体积、根系总长度和根系总表面积均显著高于CK,其中YJ4、YJ3处理均显著高于常规施肥模式。改善肥料的C/N比可以明显改善烟株的农艺性状,其中对茎围、叶宽的影响较大,YJ3、YJ4处理显著提高了烟株基部茎围和叶片宽度。5.有机各施肥模式烟株上部叶、中部叶中还原糖、总糖及钾含量显著高于常规施肥模式,而烟碱、氯的含量则显著低于常规施肥模式、CK处理。有机各施肥模式烟株上部叶、中部叶中还原糖、总糖及钾含量基本随肥料C/N的比增加呈先增加后降低趋势,均以YJ4、YJ3处理最高；有机各施肥模式烟株中部叶、上部叶中烟碱、氯的含量基本均随肥料C/N的比增加呈先降低后增加趋势,以YJ4处理最低,其次是YJ3处理。有机各施肥模式显著增加了烟叶中Fe、Mg、Zn、P含量,降低了烟叶中Cu的含量,以YJ4、YJ3处理最佳。有机施肥模式中YJ4处理总产量、总产值与常规施肥模式差异不显著,其余各处理均显著低于常规施肥模式,但有机各施肥模式较常规施肥模式显著提高了上等烟比例,显著降低了中等烟和下等烟比例,尤以YJ4、YJ3处理最佳。6.本研究揭示,采用有机施肥模式,优化肥料中C\N比组成,可以显著改善土壤的微生态环境,有利于培肥地力和烟株根系的生长,改善烟株农艺性状及烟叶品质,调节等级烟叶分配,提高土地产值。更多还原

【Abstract】 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.更多还原