Soil microorganisms are central to nutrient cycling and soil fertility, and their dynamics are strongly influenced by agricultural management practices. Peanut shell biochar has been widely applied to enhance soil fertility and reduce nutrient loss. However, its long-term effects on soil microbial communities under large-scale field conditions remain poorly understood. To address this knowledge gap, we conducted multi-year field experiments across five major tobacco-growing regions in China. Compared with the control group, long-term addition of peanut shell biochar significantly improved various soil chemical properties in Mudanjiang, Shangluo, Yichun, and Yanshan Town, including pH, available potassium, available phosphorus, organic matter, carbon-to-nitrogen ratio, alkaline hydrolyzable nitrogen, sucrase activity, catalase activity, and urease activity, while reducing the available phosphorus and catalase activity in Xuchang. Soil microbial diversity and community composition exhibited significant variation across sites, primarily shaped by differences in soil chemical properties. Although overall microbial diversity was not significantly altered by biochar addition, specific taxa, such as Firmicutes, Zoopagomycota, and Blastocladiomycota, were enriched, with Bacilli representing 70

The increasing contamination of soil with heavy metals, particularly cadmium, poses a significant threat to agricultural productivity, especially in tobacco cultivation. The primary objective of this study is to explore the impacts of biochar combined with microorganisms on tobacco resistance and soil remediation under cadmium stress. The experiment consisted of four treatments: namely, G0C0 (no cadmium or biochar added), G1C0 (cadmium 130 mg added, no biochar added), G1C1 (cadmium 130 mg added, 10 g kg −1 biochar added), and G1C2 (cadmium 130 mg added, 10 g kg −1 biochar added, and 1% microbial inoculant added). The influence of each treatment on tobacco growth and development, cadmium uptake by tobacco, soil biological characteristics, and components of soil microbial communities was investigated. The study revealed that cadmium stress had a negative impact on tobacco net photosynthesis. Notably, biochar was found to be effective in alleviating this effect. The results demonstrated that Apparent Quantum Yield (AQY), Maximum Photosynthetic Rate (Pmax), and Light Saturation Point (LSP) in G1C1 increased by 1.69%, 80.50%, and 30.76%, respectively, compared to G1C0. Similarly, AQY, Pmax, and LSP in G1C2 increased by 3.39%, 86.84%, and 62.35%, respectively. Following cadmium contamination, the levels of soil urease, catalase activity, and microbial biomass nitrogen and carbon were reduced. However, the application of biochar significantly enhanced urease and catalase activities by 12.42–63.89% and 13.03–14.17%, respectively. Additionally, the carbon and nitrogen content of microbial biomass increased by 46.42–76.27% and 21.56–28.12%, respectively, compared to the G1C0 treatment. The combined application of biochar and Trichoderma exhibited a synergistic effect, enhancing soil microbial diversity and community structure while increasing the abundance of beneficial genera such as Mucoromycota, Chaetomium, and Bacillus. Additionally, biochar effectively restricted the upward transport of cadmium in tobacco plants. These findings suggest that co-applying biochar and microorganisms offers a sustainable strategy to enhance tobacco plant resilience under cadmium stress, improve soil ecology, and promote soil remediation in contaminated environments. Graphical Abstract

Biochar-based fertilizers have the potential to improve soil quality by enhancing soil microbial communities, yet their direct effects on crop yield and quality are not well understood. To address this gap, we conducted a pot-based field study to evaluate the impact of traditional chemical fertilizers alone, traditional fertilizers supplemented with biochar, and biochar-based fertilizers on soil properties and bacterial communities. We also investigated how these treatments affected tobacco (Nicotiana tabacum) yield and leaf aroma quality. Biochar-based fertilizers increased soil carbon (C) and nitrogen (N) pools compared to the control, leading to greater bacterial diversity and richness. Consequently, tobacco biomass increased from 449 g/pot to 517 g/pot, and leaf aroma content rose from 625 mu g/g to 832 mu g/g. Linear discriminant analysis and partial least squares path modeling identified 13 key bacterial phylotypes, including plant growth-promoting bacteria (PGPB) such as Burkholderiaceae, Novosphingobium, Bacillus, Chitinophagaceae, Sphingomonas, Acidobacteriaceae, Acidobacteria, and Flavobacterium, that positively influenced tobacco leaf aroma constituents. Our findings suggest that biochar and biochar-based fertilizers enhance soil bacterial communities, which in turn improve crop yield and product quality. This study highlights the potential of biochar-based fertilizers as a sustainable agricultural practice to enhance soil health and crop quality through microbial community modulation.

以实验室筛选得到的具有抗病促生功能的哈茨木霉菌株为材料,研究其不同使用剂量对商洛烤烟生长发育及品质的影响,为哈茨木霉进行烟草绿色生产提供科学依据.2021年在陕西省商洛市洛南县开展哈茨木霉不同使用剂量的小区试验,共设4个哈茨木霉菌剂用量水平:T1(常规施肥+哈茨木霉菌剂0.5 L/hm2)、T2(常规施肥+哈茨木霉菌剂1.0 L/hm2)、T3(常规施肥+哈茨木霉菌剂2.0 L/hm2)和T4(常规施肥+哈茨木霉菌剂3.0 L/hm2),以CK(常规施肥)为对照.结果表明:(1)施用哈茨木霉菌剂的试验组烟株农艺性状、根系发育情况和烤烟抗病性较常规施肥组有明显改善;(2)随着哈茨木霉菌剂用量的增加,烤烟产量、产值及上等烟比例分别较常规施肥处理提高5.09％～12.67％、4.05％～15.05％和8.89％～21.55％;(3)各处理烤烟的糖碱比和钾氯比2个指标整体趋向更佳,有利于烤烟内在品质的提升.哈茨木霉菌剂的增施有利于提高商洛烤烟产质量,其中T3处理(常规施肥+哈茨木霉菌剂2.0 L/hm2)效果最好.

To investigate the effects of new composite water retention agents on the production of flue-cured tobacco in semi-arid areas, we investigated the effects of classical water retention agents（polyacrylate water retention agent and polyvinyl alcohol-acrylic acid water retention agent） and new composite water retention agents（biochar composite water retention agent and potassium humate composite water retention agent） on growth, activities of key enzyme in carbon, nitrogen metabolism, organic acids and conventional chemical composition of flue-cured tobacco through field trials, with no water retention agent as control. The results showed that biochar composite water retention agent and potassium humate composite water retention agent were more effective than the classical water retention agents in increasing the maximum leaf length and root volume, promoting carbon and nitrogen metabolism of tobacco leaves, and increasing the activities of amylase（AL）, neutral transforming enzyme（NI） and nitrate reductase（NR） in tobacco leaves. The biochar composite water retention agent and potassium humate composite water retention agent could significantly increase the total non-volatile organic acids in tobacco leaves. The potassium humate compound water retention agent was more effective, increasing malic acid and citric acid contents by 16.8%, 29.8% and 30.5%, 27.9%, respectively, compared with the control. The treatments also increased the contents of total sugar, reducing sugar, nicotine, potassium and chloride and sugar to alkali ratio in tobacco leaves. Application of new composite water retention agents can be beneficial in promoting flue-cured tobacco production in semi-arid areas.

探究哈茨木霉对植烟土壤细菌多样性与群落结构的影响,为优化轮作烟草根际土壤的细菌群落结构、物种组成及土壤的可持续发展奠定了一定的基础.采用大田试验方法,设置CK(常规施肥)和T1(常规施肥+哈茨木霉菌剂7.5 kg/hm2)2个处理,通过高通量测序技术探究施用哈茨木霉对各处理土壤细菌多样性、菌落结构及理化指标的影响.结果表明,哈茨木霉菌剂的施用降低了土壤细菌群落结构的α多样性指数,与常规施肥相比,增加了放线菌门(11.06％)的丰度,减少了变形菌门(4.03％)、绿弯菌门(2.28％)及酸杆菌门(1.71％)的丰度,土壤全氮和速效钾含量显著提高,分别提高14.2％和37.1％.表明在植烟土壤中施加哈茨木霉菌肥可进一步优化植烟土壤细菌群落结构,提高土壤肥力.

探究哈茨木霉配施高碳基肥对根际土壤细菌群落结构及理化性质的影响,为调控烟草微环境及改善土壤提供理论依据.采用大田试验方法,设置4个处理:T1(哈茨木霉菌剂750 kg/hm2+常规施肥)、T2(高碳基肥750 kg/hm2+常规施肥)、T3(哈茨木霉菌剂750 kg/hm2+高碳基肥750 kg/hm2+常规施肥)和CK(常规施肥),通过高通量测序技术探究哈茨木霉配施高碳基肥对根际土的细菌群落结构和土壤理化性质的影响.结果表明:(1)不同施肥处理改善根际土壤理化性质的效果总体表现为T3处理＞T1处理＞T2处理,T3处理显著提高了土壤的pH值、全氮含量、全碳含量、硝态氮含量、铵态氮含量、速效磷含量和速效钾含量(P＜0.05),增幅分别为7.63％、41.67％、20.80％、63.70％、28.98％、15.07％和9.51％;(2)烤烟根际土细菌群落结构α多样性指数在哈茨木霉菌剂和高碳基肥间存在显著互作效应,哈茨木霉菌剂处理的根际土细菌多样性指数相对较低,而CK较高且与T2处理和T3处理差异不显著;(3)LefSe分析结果表明,不同施肥处理的根际土关键微生物类群存在明显差异,且对不同施肥处理的响应也存在差异;(4)β多样性分析结果表明,3个施肥处理的根际土细菌群落结构与对照组土壤呈现明显的分离效应,高碳基肥处理的响应模式与T3处理相似,但响应程度不及后者.说明哈茨木霉菌剂和高碳基肥间存在显著互作效应.在生产中,可利用哈茨木霉配施高碳基肥改良土壤和烟草微生态环境.

China’s low nitrogen fertilizer use raises agricultural prices and environmental dangers. High-carbon fertilizer with biochar could help sequester carbon. High-carbon fertilizer was tested on roasted tobacco cultivation in Chenzhou. No-nitrogen fertilizer treatment assessed nitrogen consumption and economic benefits. Fertilizer-only and cake fertilizer treatments, substituting 13% and 26% of nitrogen with high carbon-based fertilizer, yielded the following results: Replacing 13% of N fertilizer with high-carbon fertilizer increased dry matter accumulation, utilization, agronomic efficiency, application efficiency, and production and investment ratios to 493.97 g-plant-1, 32.39%, 137.43 kg-kg-1, 65168.31 yuan-hm-2, and 8.97 yuan-yuan-1. 484.46 g-plant-1, 34.46%, 148.37 kg-kg-1, 72408.74 yuan-hm-2, and 8.04 yuan-yuan-1 at 26% replacement. High-carbon fertilizer boosted tobacco N fertilizer consumption and economic efficiency more than cake fertilizer. The 26% ratio of chemical fertilizer to organic fertilizer improved tobacco plant growth by improving nitrogen utilization. Using only chemical fertilizer nitrogen, roasted tobacco’s nitrogen distribution was 26%, 27%, 23%, and 24% in roots, stems, leaves, and flowers. Partial replacement with cake or high-carbon fertilizer boosted nitrogen distribution in roasted tobacco stems from 25% to 30%, slightly reducing in roots and leaves. The Chenzhou tobacco-rice rotation system optimizes nitrogen consumption and economic efficiency in roasted tobacco cultivation with high-carbon fertilizer. It outperforms cake fertilizer. A 26% ratio of organic nitrogen to chemical fertilizer outperforms a 13% ratio.

The changes of microbial biomass carbon,microbial biomass nitrogen,microbial diversity,microbial community structure and driving factors were analyzed in four different years including Y1（fluecured tobacco planting 1 a）,Y2（flue-cured tobacco continuous cropping 3 a）,Y3（flue-cured tobacco continuous cropping 5 a） and Y4（flue-cured tobacco continuous cropping 7 a） of tobacco planting soils in Shangluo area,the hinterland of Qinling Mountains to study the changing characteristics and driving factors of microbial community structure of flue-cured tobacco soil under different continuous cropping conditions.The results showed that the microbial biomass carbon,nitrogen and carbon nitrogen ratio decreased with the increase of planting years,with the decrease of 37.16%,20.40% and 21.10%,respectively.The abundance and diversity of bacteria in soil decreased significantly.The dominant bacteria were Actinobacteriota,Proteobacteria,Chloroflexi,Acidobacteriota and Firmicutes,with the total relative abundance accounting for 80% or more.The abundance of fungi in soil increased significantly.The dominant fungi were Ascomycota,Basidiomycota and Mucoromycota,with the total relative abundance accounting for 90% or more.Under the condition of Y4 continuous cropping,the relative abundance of beneficial microorganisms such as Firmicutes and Desulfobacterota in the soil decreased. The relative abundance of pathogenic microorganisms such as Mucoromycota and Chytridiomycota increased.Long term continuous cropping will reduce the relative abundance of beneficial microorganisms in soil,increase the relative abundance of pathogenic microorganisms,and decrease the carbon nitrogen ratio of soil microbial biomass,thereby increase the risk of tobacco disease.Therefore,the establishment of a good farming system or the construction of microbial community is the key technical way to alleviate or solve the imbalance of microbial community structure in continuous cropping tobacco fields.

为了利用光谱信息快速、实时监测烤烟叶片气孔导度状况,以K326和中烟100两个品种为试验材料,分析了正常需水量、轻度干旱、中度干旱和重度干旱4种条件下的烤烟叶片气孔导度与冠层原始光谱及一阶导数光谱间的关系,筛选出烤烟气孔导度最佳敏感波段,并构建烤烟气孔导度状况估算模型.结果表明:①随着干旱胁迫程度的加剧,烤烟叶片气孔导度和700～1350 nm波段处的冠层光谱反射率均呈现降低趋势,旺长期气孔导度高于伸根期和成熟期,两个品种表现规律一致.②敏感波段主要聚集在近红外光区域.715～930 nm、963～1000 nm处的冠层原始光谱与烤烟叶片气孔导度相关系数达0.6以上,712～715 nm和718～719 nm处的光谱一阶导数与烤烟叶片气孔导度相关系数均达0.7以上,相关性均达到极显著水平.③利用711～715 nm处光谱一阶导数所构建的BP神经网络模型效果较好,模型决定系数R2为0.908.因此,利用烤烟冠层光谱一阶导数可较精准地反映烤烟叶片气孔导度状况,其建模效果优于冠层原始光谱,其中利用711～715 nm处光谱一阶导数构建的烤烟叶片气孔导度模型效果最优.

In order to explore a resource-saving and environmentally friendly approach to reduce nitrogen fertilizer and increase soil carbon pool in crop production. There are 5 treatments in the experiment namely CK: conventional fertilization and irrigation methods (pure nitrogen 30 kg/hm2); T1: drip irrigation fertilization method (pure nitrogen 15 kg/hm2); T2: drip irrigation fertilization method (pure nitrogen 15 kg /hm2), biochar-based fertilizer 600 kg/hm2; T3: drip irrigation method (pure nitrogen 15 kg/hm2), biochar-based fertilizer 1200 kg/hm2; T4: drip irrigation method (pure nitrogen 15 kg/hm2), biochar-based fertilizer is 1800 kg/hm2. The results showed that the microbial carbon content of the biochar-based fertilizer treatment under the condition of drip irrigation to reduce nitrogen was increased by 39.9%-68.4% as compared with the control. All treatments of the biochar-based fertilizer can significantly increase the soil easily oxidizable carbon in the early and mid-term growth. The content of solid carbon and soluble organic carbon increased by 31.3%-148.31% and 12.2%-63.92%, respectively. The application of biochar-based fertilizers significantly increased the net photosynthetic rate and stomatal conductance in the early and mid-transplanting period, as well as the transpiration rate and intercellular CO2 concentration throughout the growth period, and the SPAD, NDVI value, and dry matter accumulation. Under the condition of reducing nitrogen by 50%, drip irrigation combined with biochar-based fertilizer can significantly increase the soil microbial biomass carbon content, oxidizable carbon and soluble carbon content, promote the photosynthetic effect and dry matter accumulation of tobacco plants, and it is beneficial to promote crop planting.

In this study, four different biochar application rates and a control were set up using indoor potted tobacco, to study the effects of biochar on the microbial diversity and metabolism of tobacco-growing soil. The five treatments were as follows: control—0% biochar (w/w) + 26 g fertilizer/pot; biochar treatments—1% biochar (w/w) + 26 g fertilizer/pot, 2% biochar (w/w) + 26 g fertilizer/pot, 3% biochar (w/w) + 26 g fertilizer/pot, and 4% biochar (w/w) + 26 g fertilizer/pot. We found that biochar increases the microbial diversity of soils and simultaneously changes the microbial community structure. Under the influence of biochar, soil urease activity increased by 18%, invertase activity increased by 23.40%, polyphenol oxidase activity increased by 59.50%, and catalase activity increased by 30.92%. Biochar also significantly increased the microbial biomass carbon and nitrogen content of the soil. Soil microbial biomass nitrogen had a positive correlation on bacterial diversity, with the highest coefficient, while soil microbial biomass carbon had a positive correlation on fungal diversity, with the highest coefficient. The microbial diversity and metabolic capacity of soil are improved under the influence of biochar, and soil enzyme activity and microbial biomass carbon and nitrogen have positive impacts on soil microbial diversity.

为探索生物炭对植烟土壤改良和烟草生长发育的影响效果,采用大田试验设置5个处理[T0(对照):0 t/hm2生物炭+0.64 t/hm2氮肥;T1:0.5 t/hm2生物炭+0.64 t/hm2氮肥;T2:1 t/hm2生物炭+0.64 t/hm2氮肥;T3:1.5 t/hm2生物炭+0.64 t/hm2氮肥;T4:2 t/hm2生物炭+0.64 t/hm2氮肥],分析了生物炭对植烟土壤碳排放、有机碳组分以及烟草生理指标的影响.结果表明:①与T0相比,中低用量(0.5～1.5 t/hm2)的生物炭处理可降低土壤CO2排放总量;其中T1、T2和T3处理较T0分别降低28.14％、25.25％和8.41％;而高用量(2 t/hm2)生物炭处理则促进了土壤碳排放,T4处理较T0提高8.79％.②生物炭处理可提高土壤总有机碳、微生物生物量碳、可溶性有机碳和易氧化有机碳含量(质量分数);在移栽后70 d T4处理的土壤总有机碳和微生物生物量碳含量较T0分别提高19.38％和29.38％;土壤微生物生物量碳占总有机碳比例随生物炭的施入而降低,而土壤可溶性有机碳占总有机碳比例随生物炭的施入而升高.③生物炭处理可提高烟草根系活力,改善烟草叶片光合特性,提高烟草干物质积累量;其中T3处理的烟草根系活力较T0提高80.43％.因此,适宜用量的生物炭可降低土壤碳排放量,提高土壤中碳组分含量,改善烟株根系生长发育状况和光合特性,提高烟株干物质积累量.

In order to figure out the effect of organic fertilizers with different carbon-nitrogen (C/N) ratios on the soil improvement and the healthy cultivation, the pot experiment method was used to study effects on the physical and chemical properties and the bacterial community structure of sandy loam soil using five treatments of chemical fertilizer application with the C/N ratios of 15 (CN15), 20 (CN20), 25 (CN25), 30 (CN30) and the control (CK) respectively. Results show that the organic materials with different C/N ratios significantly improve the soil porosity and water content, which all show a linear change rule with the C/N ratio. It can also significantly increase the soil total carbon, total nitrogen, soil C/N ratio, soil microbial biomass carbon, microbial biomass nitrogen and microbial biomass C/N ratio. Among them, CN30 significantly increases the soil total carbon and C/N ratio, which are 5.34-24.13% and 8.87-30.15% respectively compared with other treatments. It can be also found that the dominant flora (at the phylum level) of each treatment are Actinobacteria, Proteobacteria and Chlorobi. The CN30 treatment presents the most obvious improvement in the diversity and richness of the soil bacterial community and is more conducive to the growth and reproduction of Proteobacteria and Firmicutes. The correlation analysis shows that C-total/N-total and C-mic/N-mic are the most important environmental factors affecting the soil physical and chemical properties and their correlation with the bacterial communities. The higher C/N ratio of organic materials results in a more significant improvement of the soil physical and chemical properties. This study provides a new theoretical basis for the soil health cultivation technology.

为了利用广西本地有机肥资源开发烟草专用生物炭基有机肥,在广西百色烟区进行一年两点的大田试验.设计了八角、滤泥和牛粪3种生物炭基有机肥配方,以常规施肥为对照,研究生物炭基有机肥对烤烟生长发育和产质量形成的影响.结果表明,生物炭基有机肥显著改善了烟株的农艺性状,株高和有效叶片数提高最为明显,T1处理(八角生物炭基有机肥)效果最优;生物炭基有机肥显著改善了烟株的根系发育,根尖数、分枝数、根体积和总根长均表现出较大幅度提升,T1处理对根尖数和分枝数改善效果最为明显,在靖西试验地对这2个性状的提升效果均超过了100％;生物炭基有机肥可以提高烤后烟叶经济性状,其中产量、均价和上等烟比例明显增加;生物炭基有机肥可以优化主要化学成分含量,使其化学成分更协调.综上所述,广西当地特色有机肥资源八角和滤泥均可以与生物炭配制成生物炭基有机肥,用于烟叶生产,其中八角生物炭基有机肥效果最佳.

The usage of fertilizer with high nitrogen content in many countries, as well as its enormous surplus, has a negative impact on the soil ecological environment in agricultural system. This consumption of nitrogen fertilizer can be minimized by applying biochar to maintain the sufficient supply of nitrogen as nutrient to the near-root zone. This study investigated the effects of various amounts of biochar application (450, 900, 1350, and 1800 kg/hm2) and reduction of nitrogen fertilizer amount (10, 15, 20, and 25%) on the nutrients and microorganism community structure in rhizosphere growing tobacco plant. The microorganism community was found essential in improving nitrogen retention. Compared with conventional treatment, an application of biochar in rhizosphere soil increased the content of soil available phosphorus, organic matter and total nitrogen by 21.47%, 26.34%, and 9.52%, respectively. It also increased the abundance of microorganisms that are capable of degrading and utilizing organic matter and cellulose, such as Actinobacteria and Acidobacteria. The relative abundance of Chloroflexi was also increased by 49.67-78.61%, and the Acidobacteria increased by 14.79-39.13%. Overall, the application of biochar with reduced nitrogen fertilizer amount can regulate the rhizosphere microecological environment of tobacco plants and their microbial population structure, thereby promoting soil health for tobacco plant growth while reducing soil acidification and environmental pollution caused by excessive nitrogen fertilizer.

以烤烟品种K326为供试材料开展土培盆栽试验,在人工气候室条件下设置3种光照强度,研究叶面喷施钙素对不同光照强度下烤烟叶片光合色素、气体交换参数、抗氧化酶活性、渗透调节物质及干物质积累的影响,探明外源钙对光胁迫条件下烤烟光合生理特性及抗氧化系统的调控作用.结果表明,喷施外源钙可以增加不同光照强度下烤烟叶片的叶绿素(Chla+b)及类胡萝卜素(Car)含量,Chla+b和Car含量的最高值分别出现在400～500μmol/(m2·s)低光(L1)和1500～1800μmol/(m2·s)高光(L3)处理.烤烟叶片的净光合速率(Pn)随光强增加而升高,但光能利用效率(LUE)以L1处理最高.增施外源钙后烤烟叶片的Pn、蒸腾速率(Tr)、气孔导度(Gs)以及LUE显著增加,且在L1与L3处理下LUE增加比例较高,分别比对照增加了 3.83％～5.63％和4.65％～7.75％.高光喷钙处理的超氧化物歧化酶活性、过氧化物酶活性、可溶性糖含量以及干物质积累量最高,丙二醛含量最低.喷施外源钙可提高烟草叶片活性氧清除酶活性和渗透调节物质含量来保护光胁迫条件下光系统Ⅱ(PSⅡ)反应中心不受伤害,促进光合效率提高,有利于光合碳同化产物的积累.

为了改善广西烟叶的品质,以云烟87为材料,采用大田试验和肥料穴施的方法,研究不同用量高碳基有机肥(165、330、495 kg/hm2)对烤烟生长发育、化学成分和经济性状的影响.结果表明,高碳基有机肥对农艺性状的影响主要在上部叶,能促进上部叶的开片,最大上部叶T2和T3处理的叶长、叶宽均大于CK,叶长和叶宽最大增加量分别达到3.60、2.36 cm,叶面积为T2>T3>CK>T1;有促进根系发育的作用,尤其对根长、表面积、根尖数和分支数有明显的促进作用,根系发育整体表现为T1>T2>T3>CK;有促进干物质向茎秆和根系积累的作用,使烟株更强壮,3个处理的茎干质量、根干质量和根冠比均显著高于CK.不能改善叶斑病(靶斑病和气候斑),能预防黑胫病,3个处理的黑胫病发病率在5.20％ ～7.80％之间,远低于对照的44.40％;有提高烟叶两糖含量、钾含量的作用,适当降低烟碱的含量,提高糖碱比和氮碱比;有提高产量的作用,尤其上部叶产量明显增加,增幅在19.73％ ～32.65％之间,显著提高上等烟比例和产值,总产值的增幅在33.63％ ～56.48％之间.综合以上结果,穴施高碳基有机肥时,330 kg/hm2的用量效果最好,适宜在广西贺州地区推广.

[目的]探究施用高碳基土壤修复肥对烤烟根际土壤细菌群落结构及烟叶产值的影响.[方法]采用田间试验方式,分别设置高碳基土壤修复肥0 kg·hm-2(CK)和600 kg·hm-2(T)2组处理.[结果]烟株移栽90 d后,T处理显著提高了土壤有机质含量(23.59％)、碱解氮含量(17.41％)、pH值(1.07个单位)和含水率(24.17％);显著提高了 土壤蔗糖酶活性(97.65％)、中性磷酸酶活性(363.64％)、脲酶活性(356.60％)和过氧化氢酶活性(19.02％);显著增加了细菌Chao指数、Observed_OTUS和Shannon指数,降低了 Simpson指数.其中GAL15菌门、芽单胞菌门和硝化螺旋菌门相对丰度显著减少;奇古菌门相对丰度显著增加;显著提升了烟叶经济性状,上等烟比例和产值分别提高12.74％和12.15％.[结论]施加高碳基土壤修复肥改变了 土壤细菌群落结构,增加了土壤养分含量及酶活性,改善土壤pH值,提高了烤后烟叶品质.

在温室盆栽条件下,以黑胫病高抗品种G28、中抗品种K326和高感品种净叶黄3个烤烟品种为材料,探究哈茨木霉对不同品种烤烟植物学性状、生理特性、烟草黑胫病防治效果以及防御性酶活性的影响,以期明确哈茨木霉与烤烟品种的互作效应,为烟叶绿色生产提供理论依据.结果表明,哈茨木霉能有效促进烟株生长和生物量积累,且接种哈茨木霉对烟株叶面积的促进效果大于对株高和茎围的促进效果.与CK(清水处理)相比,接种哈茨木霉后3个品种以K326株高、茎围、叶面积、总根长、根体积以及地上部和地下部鲜质量提高幅度最大,增幅分别为54.21％、32.83％、67.42％、43.21％、119.79％、82.12％和84.16％.接种哈茨木霉后,各烤烟品种叶绿素含量、根系活力和硝酸还原酶活性随移栽后时间延长先升高后达到稳定,其中K326略高于G28和净叶黄,移栽后28 dK326叶绿素含量、根系活力和硝酸还原酶活性较CK分别升高21.45％、11.81％和29.83％.接种哈茨木霉对G28、K326、净叶黄烟草黑胫病的防治效果分别达84.09％、75.94％、67.75％,烟株根系防御性酶POD(过氧化物酶)、PPO(多酚氧化酶)、PAL(苯丙氨酸解氨酶)和CAT(过氧化氢酶)活性大幅升高,接种后各烤烟品种防御性酶活性和防治效果表现与烟草自身抗性呈正相关,表现为黑胫病高抗品种G28＞中抗品种K326＞高感品种净叶黄.综上可知,哈茨木霉通过提高烟株生理指标促进烟株生长及生物量积累,并在烟草疫霉胁迫下诱导烟草防御性酶活性升高,增强烟株对烟草黑胫病的抗性.