强还原土壤灭菌对烟草种植前后土壤化学性质及微生物群落结构的影响

Effects of reductive soil disinfestation on chemical properties and microbial community structure of soils before and after tobacco planting

强还原土壤灭菌(RSD)是一种环境友好型且能够有效缓解土壤连作障碍的技术。为了揭示RSD技术对植烟土壤品质及微生物群落结构的影响,在连作障碍严重的植烟土壤中加入有机物料豆渣,淹水覆膜后进行RSD处理,并比较植烟前后RSD处理土壤的理化性质和微生物群落的变化,同时评估RSD处理对烟草植株生长势和抗病效果的影响。结果表明,植烟前RSD处理能显著提高土壤pH、NH_(4)^(+)-N和有效磷含量(质量分数);植烟后RSD处理的土壤有效磷、速效钾和NH_(4)^(+)-N含量显著高于未处理土壤(CK1)和仅淹水覆膜处理土壤(CK2)。微生物群落分析结果显示,RSD处理可显著增加Flavisolibacter属、芽胞杆菌属(Bacillus)、粪球菌属(Coprococcus)、柄孢壳菌属(Podospora)及被孢霉属(Mortierella)的相对丰度,降低镰刀菌属(Fusarium)、丝核菌属(Rhizoctonia)和原隐球菌属(Saitozyma)的相对丰度,尤其能显著降低青枯病致病菌属(Ralstonia)的相对丰度。与CK1和CK2相比,RSD处理土壤烟株农艺性状(株高、有效叶片数和最大叶面积)得到一定程度的改善,烟草青枯病发病率分别降低59.00%和49.58%。因此,RSD处理土壤能显著改善土壤微生物群落结构,有利于土壤养分提高和烟株生长发育。

Reductive soil disinfestation(RSD)is an effective and environmental-friendly technology that can overcome the obstacle of soil quality in continuous cropping.To investigate the effects of RSD technology on the quality and microbial community structure of soils before and after tobacco planting,organic bean dregs were applied and RSD treatment was conducted after flooding and plastic film mulching in soils with the serious obstacle of continuous cropping.The changes of chemical properties and microbial community structure in the soils treated by the RSD technology before and after tobacco planting were compared,and the effects of the RSD treatment on tobacco growth vigor and disease resistance were evaluated.The results showed that the RSD treatment before tobacco planting significantly increased the pH value,the contents of NH_(4)^(+)-N and available phosphorus(mass fraction)of the soils.The contents of available phosphorus,available potassium and NH_(4)^(+)-N in the soils treated with the RSD after tobacco planting were significantly higher than those of untreated soils(CK1)as well as the flooded and plastic film mulched soils(CK2).The results of microbial community analysis indicated that the RSD treatment significantly raised the relative abundances of Flavisolibacter,Bacillus,Coprococcus,Podospora and Mortierella,while reduced those of Fusarium,Rhizoctonia and Saitozyma,especially that of bacterial wilt pathogen—Ralstonia.Compared with CK1 and CK2,the RSD treatment promoted the agronomic traits(plant height,number of effective leaves,maximum leaf area)of tobacco plants to some extent and reduced the incidence rate of bacterial wilt by 59.00%and 49.58%respectively.Thereby,the RSD treatment of soil can significantly improve soil microbial community structure and is beneficial to the improvement of soil nutrient as well as tobacco growth and development.