不同轮作模式下土壤细菌群落特征及其对土壤全碳、全氮与温室气体释放潜力影响

为了探讨不同轮作模式下农田土壤细菌群落特征对土壤全碳(TC)、全氮(TN)含量及温室气体释放潜力的影响,以安徽铜陵两种不同轮作模式农田土壤为研究对象,设置旱-旱轮作(姜-菜)及水-旱轮作(姜-稻)两种轮作模式样地,测定并分析土壤细菌群落及其多样性、土壤TC、TN含量及CH₄和N₂O释放潜力.结果表明,旱-旱和水-旱轮作模式下姜季均降低了土壤TC、TN含量,水-旱轮作模式下稻季增加了土壤CH₄释放潜力(p<0.05),其他时期CH₄和N₂O释放潜力差异不显著.不同轮作模式对土壤细菌群落多样性影响不同,细菌多样性指数表现为水-旱轮作模式>旱-旱轮作模式(p<0.05).水-旱轮作相比于旱-旱轮作节杆菌属(Arthrobacter)相对丰度增加,鞘氨醇单胞菌属(Sphingomonas)和芽胞杆菌属(Bacillus)相对丰度降低.芽胞杆菌属、Gaiella、Paenibacillus、Blastococcus等菌属在不同轮作模式下呈显著差异(p<0.05).Bryobacter、Bradyrhizobium和Mycobacterium与土壤C/N呈显著正相关(p<0.05).Acidothermus、Geodermatophilus、Blastococcus、Bacillus、Paenibacillus菌属对土壤N₂O释放有显著负效应(p<0.05).Conexibacter、Acidothermus和Geodermatophilus菌属对土壤CH₄释放具有显著正效应(p<0.05).本研究的开展对农田管理方式的选择及可持续生产均具有重要意义.

Effects of soil bacterial community characteristics on total carbon and total nitrogen contents and greenhouse gas emission potential under different rotation patterns

In order to explore the effects of soil bacterial community characteristics on soil TC,TN content and greenhouse gas emission characteristics under different rotation patterns,two different rotation patterns of farmland soil in Tongling,Anhui Province were set up to analyze soil bacterial community and diversity,soil TC,TN content and CH₄ and N₂O emission potential. The results showed that: under dryland-dryland rotation,the contents of soil TC and TN were decreased in ginger season,while CH₄ release potential was increased in rice season under paddy-upland rotation (p<0.05). Different rotation patterns had different effects on the diversity of soil bacterial community,and the bacterial diversity index was in the order of paddy-upland rotation > dryland-dryland rotation (p<0.05). The relative abundance of Arthrobacter increased,Sphingomonas and Bacillus decreased in paddy-upland rotation compared with dryland-dryland rotation. Bacillus, Gaiella, Paenibacillus and Blastococcus showed significant differences under different rotation patterns (p<0.05). Bryobacter, Bradyrhizobium and Mycobacterium had significant positive effects on soil C/N (p<0.05). Acidothermus, Geodermatophilus, Blastococcus, Bacillus and Paenibacillus had significant negative effects on soil N₂O emission (p<0.05). Conexibacter, Acidothermus and Geodermatophilus had significant positive effects on CH₄ emission (p<0.05). The development of this study is of great significance to the choice of farmland management mode and sustainable production.