厌氧消毒对植烟土壤质量及细菌群落结构的影响

摘要

In order to explore the effects of anaerobic soil disinfection (ASD) with the additions of different organic substances on the quality and bacterial community structure of the soil, ASD treatments were carried out by adding tobacco stem, rice straw, rapeseed meal, rice bran, sugarcane bagasse, with no addition (CK1), and the primary soil (CK) as controls. The results showed that ASD increased soil pH and reduced soil EC and Eh significantly, and improved soil nutrients. Tobacco stem increased the contents of available potassium and organic matter significantly, while rapeseed meal raised the contents of total nitrogen, organic matter, available nitrogen and the activities of catalase and urease. Sequencing of soil bacteria by 16S rDNA showed that ASD changed the ratios of soil bacterial communities at the phylum level, and there were obviously differences in the treatments of different organic substances. Significant differences were found in the bacterial composition of rapeseed meal and tobacco stem treatments when compared with CK and CK1. The relative abundances of the anaerobic bacteria Clostridiaceae, Ruminococcaceae, and Bacillaceae were also greatly improved, while the numbers of R.solanacearum treated with ASD were greatly reduced, especially for the treatments of adding rapeseed meal and tobacco stem . In conclusion, ASD with the addition of different organic substances had obviously different effects on the physical and chemical properties and bacterial community structure of the tobacco-planting soil. ASD by adding rapeseed meal and tobacco stem significantly improved the soil nutrients, and changed the composition and diversity of the bacterial community, and increased the abundance of anaerobic and tolerant bacteria, which, in turns, decreased the number of R.solanacearum significantly.%为了解添加不同有机物料的土壤厌氧消毒(Anaerobic soil disinfection,ASD)对土壤质量及细菌群落结构的影响,设置了烟梗、水稻秸秆、菜粕、米糠、甘蔗渣5种有机物料和不添加物料(CK1)的ASD处理,以原始土壤为对照(CK),分析了不同处理的土壤质量和细菌群落结构.结果表明,与CK相比,ASD处理均可显著提高土壤pH,降低土壤EC和Eh,改善土壤养分,其中添加烟梗显著提高了速效钾、有机质的含量,菜粕显著提高了全氮、有机质、速效氮含量及过氧化氢酶以及脲酶的活性.利用16S rDNA对土壤细菌测序表明,ASD显著改变了细菌门类水平上各种群的比例,其中添加菜粕和烟梗的ASD处理微生物构成与CK、CK1差异较大,厚壁菌门及其门下厌氧型细菌梭菌科、瘤胃菌科和耐受性细菌芽孢杆菌科的相对丰度显著增加,而其土壤青枯菌数量却显著降低.总的来看,添加不同有机物料的ASD对植烟土壤的理化性状和细菌群落结构可产生显著不同的影响,其中添加菜粕和烟梗的ASD明显改善土壤养分,影响了土壤细菌群落结构组成及其多样性,厌氧和耐受型细菌丰度大幅增加,青枯菌数量减少.