炉渣与生物炭施加对稻田土壤铁还原菌群落结构及甲烷排放影响

Slag and biochar application on community structure and methane emission of iron-reducing bacteria in paddy soil

为了探究炉渣及生物炭施加处理对稻田土壤铁还原菌群落结构及甲烷排放的影响,在福州某平原稻田中分别进行施加生物炭、炉渣、生物炭+炉渣3种处理,测定早、晚稻生长期稻田甲烷排放通量和可培养铁还原菌数量,并比较施加处理与不施加处理稻田土壤铁还原菌群落结构组成之间的差异.结果表明:废弃物施加能够改变稻田土壤铁还原菌数量,晚稻生物炭施加组的铁还原菌数量显著高于其他3组(P<0.05);废弃物施加在一定程度上抑制了稻田土壤甲烷的排放,其中早稻混合施加组对甲烷排放的降低作用最为明显;福州平原稻田土壤中铁还原菌种类丰富,分布于10个门,其中厚壁菌门(Firmicutes)和变形菌门(Proteobacteria)为优势菌门相对丰度占比之和大于95%.共鉴定出20个属,其中相对丰度较高的菌属为芽孢杆菌属(Bacillus)、厌氧粘细菌属(Anaeromyxobacter)、梭状芽孢杆菌属(Clostridium)等10个属,占样品中已知铁还原菌属的62.07%~66.58%;生物炭和炉渣主要通过改变土壤pH值及含水量影响稻田土壤铁还原菌群落结构,混合施加的影响比单一施加更为显著;芽孢杆菌属(Bacillus)的相对丰度与稻田土壤甲烷的排放通量呈显著负相关,是稻田中抑制甲烷产生与排放的主要铁还原菌属.

In order to explore the effects of slag and biochar application treatment on the community structure and methane emission of iron-reducing bacteria in paddy soil, applied three kinds of treatments, namely biochar, slag and biochar + slag, in a paddy field in Fuzhou to measure early and late paddy. The methane emission flux during the paddy growing season and the number of culturable iron-reducing bacteria were compared, and the difference between the composition of the iron-reducing bacteria and the community composition of the soil in the paddy field was compared. The application of waste could change the quantity of iron-reducing bacteria in paddy soil, and the number of iron-reducing bacteria in the late-season biochar application group was significantly higher than that in the other three groups(P<0.05);the waste was applied to a certain extent. Methane emissions from paddy soils were inhibited, and the early rice mixed application group had the most significant reduction in methane emissions. The iron-reducing bacteria in the paddy soil of Fuzhou Plain are rich in species, distributed in ten gates, of which Firmicutes and Proteobacteria are dominant bacteria, and the sum of abundance is greater than 95%. A total of 20 genera were identified, among which the abundance of the genus Bacillus, Anaeromyxobacter, Clostridium and other ten genus, accounting for 62.07%~66.58% of the known iron-reducing genus in the sample;biochar and slag mainly by changing soil pH and water content, the community structure of iron-reducing bacteria in paddy soil was affected, and the effect of mixed application was more significant than single application. The number of Bacillus is significantly negatively correlated with the methane emission flux of paddy soil, and it is the main genus of iron reduction to inhibit methane production and emission.