Journal of Integrative Agriculture ›› 2026, Vol. 25 ›› Issue (9): 3882-3892.DOI: 10.1016/j.jia.2025.12.063

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农田土壤异源性有机组分分解特征及微生物底物利用策略的调控作用

  

  • 收稿日期:2025-08-01 修回日期:2025-12-31 接受日期:2025-12-02 出版日期:2026-09-20 发布日期:2026-08-11

Distinct decomposition dynamics of heterogeneous carbon components in cultivated agricultural soils controlled by flexible microbial substrate utilization strategy

Wanqi Wang1, 2, 3*, Xuefeng Zhu1, 3*, Yuzhu Li1, 3, Shuhan Dong1, 2, 3, Yan Liu4, Kaikai Min1, 3, Huijie Lü5, 6, Wei Zhang1, 3, Hongbo He1, 3#, Xudong Zhang1, 3   

  1. 1 Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China

    2 University of Chinese Academy of Sciences, Beijing 100049, China

    3 Key Laboratory of Conservation Tillage and Ecological Agriculture of Liaoning Province, Shenyang 110016, China

    4 College of Environmental and Chemical Engineering, Shenyang Ligong University, Shenyang 110159, China

    5 Bayingol Vocational and Technical College, Korla 841000, China

    6 Xinjiang Key Laboratory of Sustainable Management of Salinized Land and Regional Agricultural Technology, Korla 841000, China

  • Received:2025-08-01 Revised:2025-12-31 Accepted:2025-12-02 Online:2026-09-20 Published:2026-08-11
  • About author:Wanqi Wang, E-mail: wangwanqi20@mails.ucas.ac.cn; Xuefeng Zhu, E-mail: zhuxuefeng@iae.ac.cn; #Correspondence Hongbo He, E-mail: hehongbo@iae.ac.cn * These authors contributed equally to this study.
  • Supported by:

    This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA28010301), the National Natural Science Foundation of China (U22A20610), the Key Research and Development Program of Xinjiang Uygur Autonomous Region, China (2025B04046), the Grassroots Science and Technology Backbone Talents under the Tianshan Talents Initiative of the Xinjiang Uygur Autonomous Region, China (2024TSYCJC0041), the Outstanding Young Scientist Program of the Institute of Applied Ecology, Chinese Academy of Sciences (2023000153), and the Natural Science Foundation of Shenyang, China (23-503-6-19).

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摘要：

土壤有机碳的积累与稳定是维持陆地碳汇与生态系统功能的关键。保护性耕作有利于东北农田退化土壤有机质的积累。然而，不同有机组分对培肥土壤有机质稳定性的贡献以及微生物调控机制并不清楚。本研究利用免耕土壤（对照）和经过12年全量秸秆还田的土壤进行室内矿化培养试验并定期取样。通过测定培养过程中土壤木质素、中性糖和氨基糖的含量变化，并同步分析磷脂脂肪酸和胞外酶活性的动态特征，从而明确微生物的响应及其对土壤有机碳矿化的调控作用。研究结果表明，培养1年后，培肥土壤有机碳下降比例显著低于对照（12.3 vs. 14.5%），表明长期秸秆归还提高了土壤有机质的稳定性。在培养过程中，木质素的下降幅度（20.8-26.3%）大于土壤有机碳和氨基糖（10.6-12.3%），表明植物残体分解主导了土壤有机碳的矿化，而微生物残体主要贡献于土壤有机质的稳定性。此外，中性糖和木质素的分解动态受到碳可利用性的显著影响。在对照土壤中，中性糖和木质素分解动态相似且总体下降幅度无显著差异，表明两种生物化学稳定性不同的组分存在共代谢过程，该过程主要和放线菌丰度增加直接相关；在培肥土壤中，中性糖优先于木质素被微生物分解利用，这种底物选择性不仅受到碳水化合物水解酶的调控，也与微生物群落从细菌主导向真菌贡献增加的转变密切相关。综上，本研究揭示了土壤肥力提高对微生物底物利用策略的影响及其对土壤有机质分解过程的调控作用，并明确了不同组分在土壤有机碳周转与稳定化中的差异性贡献。

Abstract:

Improving soil organic matter (SOM) maintenance is crucial for terrestrial carbon (C) sequestration and ecosystem functioning.  Conservation tillage favors SOM pool buildup; however, it remains unclear how the decomposition of heterogeneous components is manipulated by microbial substrate utilization strategy from the view of SOM stability.  Here, a one-year microcosm incubation was conducted using surface soils developed under 12 years of conservation tillage (high-C soil) and maize residue removal (low-C soil).  Temporal changes in lignin phenols, neutral sugars, and amino sugars in the soil were monitored along with microbial phospholipid fatty acids (PLFAs) and enzyme activities.  Throughout incubation, lignin phenols declined more (20.8–26.3%) than the SOM (12.3–14.5%) and amino sugars (10.6–12.3%), highlighting the key role of plant debris in SOM mineralization, and complementarily, the greater contribution of microbial necromass to SOM stabilization.  Moreover, the decomposition dynamics of neutral sugars and lignin were strongly influenced by C availability.  In the low-C soil, these two types of compounds decomposed with similar temporal patterns and extents, and such substrate co-metabolism was dominantly mediated by actinomycetes.  In contrast, in the high-C soil, a lower oxidases-to-carbohydrolases ratio regulated the sequential decomposition of labile neutral sugars followed by recalcitrant lignin.  Such microbial substrate selectivity was associated with a shift in microbial community from bacterial dominance toward increased fungal contribution.  Overall, our findings underscore the significant interplay between soil C availability and flexible microbial substrate utilization strategy in regulating decomposition of heterogeneous SOM components, as well as their distinct contributions in SOM turnover and stabilization.

Key words: SOM decomposition , microbial necromass , lignin phenols , carbohydrates , microbial community , microbial substrate utilization strategy