Supported by the Special Fund for Scientific Research on Agricultural Public Causes of China (No. 201503121-04), the Agricultural Science and Technology Innovation Program of CAAS and the National Key R&D Program of China (No. 2016YFD0201009)
采用细菌16S rRNA基因高变区和真菌ITS区的Illumina MiSeq高通量测序技术结合分子生态网络方法，分别测定了5种施肥处理（常量化肥，NPK；化肥减量，NPKR；化肥减量配施秸秆，NPKRS；化肥减量配施有机肥，NPKRO；化肥减量配施有机肥和秸秆，NPKROS）土壤中细菌和真菌的群落组成，构建可视化分子生态网络，并针对土壤有机质（soil organic matter，SOM）进行相关性网络分析，探究化肥减量和有机替代下土壤微生物群落分子生态网络及有机质相关性网络的变化特征。结果表明，化肥减量和有机替代显著提高了土壤SOM含量。与NPK处理相比，在细菌分子生态网络中，化肥减量和有机替代处理均增加了网络节点数和边数，降低了平均路径长度；在真菌分子生态网络中，NPKR处理提高了网络节点数和边数；有机替代处理增加了平均路径长度，降低了平均聚类系数；化肥减量和有机替代处理下与土壤SOM含量显著正相关的细菌菌群占比增加，真菌菌群占比降低。综上所述，化肥减量和有机替代能提高细菌分子生态网络规模和物种间传递物质、能量和信息的效率。化肥减量能提高真菌分子生态网络规模和群落互作，有机替代使真菌群落结构更加稳定。
[Objective] The use of organic manure as alternative for chemical fertilizer has been recommended as an effective method to mitigate impacts of chemical fertilizer on the agricultural system and improve soil fertility. However, how soil microbial communities respond to the organic input following fertilizer reduction remains poorly understood.[Method] In the current study, the technique of Illumina MiSeq sequencing combined with the construction of molecular ecological networks was used to investigate community composition and structure of the molecular ecological network of the soil bacteria and fungi in the field of fluvo-aquic soil under a wheat-maize rotation system. Furthermore, correlation networks between soil organic manure (SOM) content and bacterial and fungal communities were constructed. The fertilization regimes were designed as follows:conventional chemical fertilizer (NPK), reduced chemical fertilizer (NPKR), chemical fertilizer partly substituted with straw (NPKRS), chemical fertilizer partly substituted with organic manure (NPKRO), chemical fertilizer partly substituted with organic manure and straw (NPKROS).[Result] Results show that chemical fertilizer reduction and organic substitution significantly increased the content of soil SOM. In the case of bacterial community ecological network, compared with Treatment NPK, the treatments of chemical fertilizer reduction and organic substitution increased the numbers of network nodes and edges, but reduced the average path length. Treatments NPKRS and NPKROS were higher than the other three treatments in average clustering coefficient and the network density. With respective to fungal ecological network, Treatment NPKR increased the numbers of network nodes and edges, while the organic substitution treatments increased the average path length and reduced the average clustering coefficient, as compared to Treatment NPK. Treatment NPKR was the highest in network density among all treatments, but the lowest in modularity. Compared with Treatment NPK, all the other treatments increased the proportion of bacterial flora that were significantly and positively related to soil SOM content, but decreased the proportion of fungal flora that were significantly and negatively related to soil SOM content. Some flora, like Proteobacteria, Chloroflexi, Actinobacteria, Gemmatimonadetes, Bacteroidetes, Firmicutes and Acidobacteria, play an important role in the soil bacterial molecular ecological network, while some, like Ascomycota, Basidiomycota and Glomeromycota, do a significant one in the soil fungal molecular ecological network.[Conclusion] In conclusion, partial substitution of chemical fertilizer with organic manure or material increases the bacterial molecular ecological network in size, while simultaneously improving the transferring efficiency of substances, energy and information among species. The substitution with straw enhances interaction between bacterial communities and makes the bacterial community more sensitive to disturbance of the external environmental factors. The reduction of chemical fertilizer increases the fungal molecular ecological network in size and community interaction, and the substitution with organic manure or material improves stability of the fungal community structure.
吴宪,胡菏,王蕊,赵建宁,杨殿林,王丽丽,李刚,修伟明.化肥减量和有机替代对潮土微生物群落分子生态网络的影响[J].土壤学报,2022,59(2):545-556. DOI:10.11766/trxb202008130260 WU Xian, HU He, WANG Rui, ZHAO Jianning, YANG Dianlin, WANG Lili, LI Gang, XIU Weiming. Effects of Reduction of Chemical Fertilizer and Substitution Coupled with Organic Manure on the Molecular Ecological Network of Microbial Communities in Fluvo-aquic Soil[J]. Acta Pedologica Sinica,2022,59(2):545-556.复制