不同碳氮比杨梅枝条堆肥的养分含量和细菌群落变化

Effects of different carbon and nitrogen ratios on nutrient content and bacterial community changes in compost made from Morella rubra branches

为了研究不同碳氮比对杨梅枝条堆肥发酵过程中养分、腐殖质组分及细菌群落结构的影响,设置碳氮比分别为30∶1、60∶1,90∶1进行杨梅枝条堆肥发酵试验,测定各处理养分和腐殖质组分,对细菌群落采用细菌16S rRNA Illumina Miseq高通量测序,比较细菌相对丰度,分析细菌群落Alpha和Beta多样性,及堆肥养分因子与细菌群落相关性。结果表明,杨梅枝条堆料处理的全氮、全磷、全钾含量随碳氮比增加而减少,有机质和胡敏素含量随碳氮比增加而增加;全氮、全钾、胡敏酸和富里酸含量随发酵时间延长显著增加,有机质和胡敏素含量则显著减少(p<0.05);碳氮比与有机质、全氮和胡敏素呈极显著相关。3个处理的厚壁菌门和放线菌门细菌的相对丰度随碳氮比增加而增加,变形菌门和拟杆菌门细菌的相对丰度随碳氮比增加而减少;在高温阶段厚壁菌门和放线菌门细菌的相对丰度明显高于其他阶段。不同碳氮比处理的细菌群落丰富度和多样性存在明显差异。碳氮比对枝条堆体细菌群落结构起决定性作用,全氮、有机质和温度也对枝条堆体细菌群落结构有一定的影响。堆体细菌群落结构与碳氮比、全氮和有机质之间存在显著相关性。说明碳氮比对杨梅枝条堆肥养分含量和细菌群落分布具有关键性作用。

In order to study the effects of different C/N ratios on the nutrient,humus components and bacterial community structure in the process of fermentation and composting of Morella rubra branches,C/N ratios of 30:1,60:1 and 90:1 were set for compost of Morella rubra branches to determine the nutrient and humus components,to compare the relative abundance of bacteria,analyze the Alpha and Beta diversity of bacterial community and the correlation of compost nutrient factors to bacterial community by 16S rRNA Illumina Miseq high-throughput sequencing of bacterial community.The results showed that the contents of total nitrogen(TN),total phosphorus(TP)and total potassium(TK)decreased with the increase of C/N ratio,while the contents of organic matter(OM)and humin(HM)increased with the increase of C/N ratio.The contents of TN,TK,humic acid(HA)and fulvic acid(FA)increased significantly with the extend of fermentation time,while the contents of OM and HM decreased significantly with the extend of fermentation time(p<0.05).C/N ratio was extremely significantly correlated with OM and TN(p<0.01).The relative abundance of Firmicutes and Actinobacteria bacteria decreased with the increase of C/N ratio,while the relative abundance of Proteobacteria and Bacteroides bacteria increased with the increase of C/N ratio.In the high temperature stage,the relative abundance of Firmicutes and Actinobacteria bacteria was significantly higher than that of other stages.The abundance and diversity of bacteria communities in different C/N treatments were significantly different.The C/N ratio played a decisive role in the bacterial community structure of the compost pile,and the TN,OM and temperature also had certain effects on the bacterial community structure of the compost pile.There was a significant correlation between bacterial community structure and C/N ratio,TN and OM,which showed that C/N ratio played a key role in the nutrient content and bacterial community distribution in compost of Morella rubra branches.