Li Jingwang, Chen Lin, Zhang Jiabao, Zhang Congzhi, Ma Donghao, Zhou Guixiang, Ning Qi
Fengqiu Experimental Station of National Ecosystem Research Network of China, State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.
University of Chinese Academy of Sciences, Beijing, China.
Front Microbiol. 2023 Jan 18;14:1087709. doi: 10.3389/fmicb.2023.1087709. eCollection 2023.
Soil microbial use efficiency of straw carbon (C), which is the proportion of straw-C microbes assimilate into new biosynthetic material relative to C lost out of the system as CO, is critical in increasing soil organic C (SOC) content, and hence maintaining soil fertility and productivity. However, the effect of chemical structures of the organic amendments (OAs) on the microbial use efficiency of straw-C remains unclear. The effect of the chemical structure of the OAs on microbial use efficiency of straw-C was elucidated by a combination of C-straw labeling with high-throughput sequencing and pyrolysis-GC/MS. We found a strong positive correlation between the microbial use efficiency of straw-C and the proportion of heterocyclic compounds (Hete_C). The microbial use efficiency of straw-C was highest in soil supplemented with Hete_C-dominant OAs, which significantly shifted microbial community structure toward fungal dominance. Specifically, fungal-to-bacterial ratio, fungal richness, and the relative abundance of were higher in soil with a higher proportion of Hete_C-dominant OAs. Together, our study suggests that OAs with high proportion of Hete_C promote the microbial use efficiency of straw-C by increasing the dominance of fungi in the soil microbial community in agroecosystems.
秸秆碳的土壤微生物利用效率，即秸秆碳被微生物同化为新的生物合成物质的比例相对于以二氧化碳形式从系统中损失的碳的比例，对于增加土壤有机碳（SOC）含量，进而维持土壤肥力和生产力至关重要。然而，有机改良剂（OAs）的化学结构对秸秆碳微生物利用效率的影响仍不清楚。通过碳秸秆标记与高通量测序和热解-气相色谱/质谱联用，阐明了OAs化学结构对秸秆碳微生物利用效率的影响。我们发现秸秆碳的微生物利用效率与杂环化合物（Hete_C）的比例之间存在很强的正相关关系。在添加以Hete_C为主的OAs的土壤中，秸秆碳的微生物利用效率最高，这显著地使微生物群落结构向真菌主导转变。具体而言，在以Hete_C为主的OAs比例较高的土壤中，真菌与细菌的比例、真菌丰富度以及[此处原文缺失相关内容]的相对丰度更高。总之，我们的研究表明，高比例Hete_C的OAs通过增加农业生态系统土壤微生物群落中真菌的主导地位来促进秸秆碳的微生物利用效率。
