Reasonable fertilization management can increase nutrient content and enzyme activity in rhizosphere soil, and even increase soil microbial richness. However, different fertilizers could raise distinct influences on the soil properties, including soil environmental factors (physicochemical properties and enzymatic activities) and microbial community. Here, the effects of two soil amendments (microbial fertilizer and woody peat) on environmental factors and microbial community structure in tobacco rhizosphere soil were evaluated, with the correlations between microbes and environmental factors explored. As the results, microbial fertilizer could effectively alleviate soil acidification, increase available potassium and organic matter contents in soil, and was also beneficial to increase nitrate reductase activity in rhizosphere soil. Fertilizers cause changes in the abundance of certain microbes in the soil. Besides, it was shown that the candidate phyla Gal15, Acidobacterota, Latescibacterota, Mortierellommycota, Basidiomycota, and Rozellomycota in tobacco rhizosphere soil had significant correlation with soil environmental factors. Through the functional analysis of these populations, it can be deduced that the changes in the abundance of certain microorganisms may be an important reason for the differences in environmental factors. All these indicated that the differences of environmental factors in different treatments are closely related to the abundance of some special soil microorganisms. Studying the life activities of these microbes would provide good guidance for exploring the interaction among crops, soil, and microorganisms and improving crop yields.

为明确种植管理措施对皖南烟区烤烟生长和产质量的影响,确定适宜的种植配套组合.设置不同烤烟种植密度、留叶数和采收次数配套处理并与"打叶方式"(上下双打或仅打上部)进行耦合试验,对不同处理的农艺性状、经济性状、外观质量、化学指标和感官品质进行综合考量.结果表明:50cm×130cm株行距种植密度可以促进单株烤烟的生长发育,但不利于提升烟叶整体的产量和产值;35cm×120cm的株行距作为皖南烤烟的栽培密度,配合双打的打叶方式,可以有效增加烟叶的产量,而配合打顶弃采的打叶方式,可以提升烟叶的外观质量和化学成分配比的适宜性;27cm×120cm株行距虽然不利于烤烟养分的吸收,但通过控制留叶数,使烟叶的养分供应得到保证,确保中部烤烟感官品质和产量的稳定.针对皖南烟区,采用35cm×120cm的株行距、留叶数控制在10片、两次采收(4-6)、双打的"打叶方式"的组合最适宜烤烟产质量的提升.

为明确亚热带季风性湿润气候下不同根层空间对烤烟品质和均质化的影响,在皖南烟区设计不同垄高(25、35、45 cm)和垄宽(60、70、80 cm)双因素试验,共9个处理,通过烤烟长势和理化指标确定不同处理对烟叶品质的作用,通过烤烟理化指标变异系数确定烟叶均质化水平.结果表明:Ⅲ处理(25 cm×80 cm)有助于团棵期烤烟生长,Ⅴ处理(35 cm×70 cm)、Ⅵ处理(35 cm×80 cm)对平顶期长势促进作用较大;35 cm垄高对烟叶的品质促进作用明显,其中Ⅳ处理(35 cm×60 cm)的烟叶产值最高,Ⅴ处理(35 cm×70 cm)的单株干物质积累最大,Ⅵ处理(35 cm×80 cm)外观评价和化学成分适宜性最好;且Ⅵ处理(35 cm×80 cm)的烟叶物理指标和化学指标的均质化水平最高.

Quicklime has been used to improve acidic soils for several decades. The influence of quicklime on the microbial community in strong acidic soil of tobacco plants was investigated. Quicklime at concentrations of 0.75, 2.5, and 4.5 g·kg−1 was mixed with the soil for an incubation experiment. The soil physicochemical properties and enzyme activities of each samples were measured, and microbial diversity of the samples at different periods were determined using high-throughput sequencing. Quicklime had a significant impact on the pH, cation exchange capacity, NO3−–N, NH4+–N, K, and P of the soil. Additionally, quicklime contributed to the increased soil urease and soil β-glucosaminidase activities. According to high-throughput sequencing, the microbial diversity had not significantly increased by the 20th day due to quicklime. Similarly, on the 50th day, the diversity of bacteria significantly increased whereas that of fungi was not affected when the quicklime concentration was 0.75 g·kg−1. Rhodanobacter, Gaiellales, Streptomyces, Terrabacter, and Acidobacteriales were the key bacterial genera and Mortierella, Penicillium, Trichoderma, Aspergillus, Talaromyces, and Fusarium were the fungal genera which were affected on the 50th day. Redundancy analysis indicted that pH was an important environmental factor affecting fungal and bacterial communities. Quicklime concentration of 0.75 g·kg−1 positively affected the microbial community in strongly acidic soils of tobacco plants (pH <5).

为明确生物有机肥对胶州烟区烟叶内在品质及安全性的影响,研究生物有机肥施用对烤烟田间农艺性状、经济性状、化学成分、重金属含量及农药残留的影响.结果表明,与对照相比,施用生物有机肥能够提高胶州烟区烤烟长势、产值产量、内在品质;除汞外,生物有机肥能够降低7种重金属及农药残留.可见,生物有机肥能够促进烟株生长发育,提高烟叶质量,减少烤烟重金属含量及农药残留,提高烤烟的安全性.

[目的]明确有机肥施用方式及起垄高度对烤烟生长发育及品质的影响.[方法]研究了有机肥施用方式及起垄高度对烤烟农艺性状、经济性状、化学成分及外观质量的影响.[结果]有机肥穴施条件下,提高垄高能够促进烟株生长,增加产量、产值,而条施有机肥在垄高35 cm时烟株生长最佳;在垄高35、45 cm条件下有机肥条施烤烟经济性状比穴施好;提高垄高能改善烤烟中部叶外观质量;与有机肥条施相比,穴施能够促进内在化学成分的协调性.[结论]在穴施条件下,45 cm垄高的烟叶品质最佳,而在条施条件下,以35 cm垄高烤烟生长发育及产值最好.