Journal of Integrative Agriculture ›› 2026, Vol. 25 ›› Issue (8): 3427-3439.DOI: 10.1016/j.jia.2025.12.061

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作物轮作驱动土壤团聚体重构增强了中国黄土高原肥料氮的保持能力

  

  • 收稿日期:2025-06-18 修回日期:2025-12-29 接受日期:2025-12-12 出版日期:2026-08-20 发布日期:2026-07-09

Crop rotation-induced soil aggregate restructuring enhances fertilizer nitrogen retention on the Loess Plateau of China

Haidi Wang1, 2, Bin Yan1, 2, Xingkang Ma1, 2, Yuhong Gao1, 2#, Zhengjun Cui3, Bing Wu4, Yifan Wang1, 2, Jing Han1, 2, Mingli Wan1, 2   

  1. 1 State Key Laboratory of Aridland Crop Science/College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China

    2 Seed Industry Research Institute, Gansu Provincial University, Lanzhou 730070, China

    3 College of Agriculture, Tarim University, Alaer 843300, China

    4 College of Life Science and Technology, Gansu Agricultural University, Lanzhou 730070, China

  • Received:2025-06-18 Revised:2025-12-29 Accepted:2025-12-12 Online:2026-08-20 Published:2026-07-09
  • About author:Haidi Wang, E-mail: wanghd1823@163.com; #Correspondence Yuhong Gao, E-mail: gaoyh@gsau.edu.cn
  • Supported by:

    This study was supported by the Earmarked Fund for China Agriculture Research System (CARS-14-1-16), the National Natural Science Foundation of China (32260551), the Research Program Sponsored by Gansu Provincial Key Laboratory of Aridland Crop Science, Gansu Agricultural University, China (GSCS-2020-Z6), the Technology Innovation Guidance Program Science and Technology Mission Topic of Gansu Province, China (23CXNA0035), and the Gansu Education Science and Technology Innovation Industry Support Program, China (2021CYZC-38).  

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摘要：

土壤团聚体高度调控氮（N）循环过程，但其在长期轮作条件下调节氮素固持的功能尚不明确。本研究通过15N标记肥料试验，探究长期轮作系统中不同粒径土壤团聚体如何调节肥料氮的保持与再分配。结果表明，大团聚体对肥料氮的贫化作用（富集因子（Ef）：0.73−0.95）较全氮（Ef：0.93−1.00）更为显著；相反，小团聚体和微团聚体均表现出对肥料氮的富集作用（Ef：1.00−1.16）。至关重要的是，我们发现了团聚体在时间尺度上的功能分异：在作物收获后（伴随新的15N标记肥料施入），小团聚体优先固持新施用的氮肥（当季肥料氮），而在2024年未施15N标记肥料条件下，微团聚体则主导旧氮（上一年施用的肥料氮）稳定。这种功能分异由团聚体周转过程驱动，即崩解的小团聚体释放旧氮并转移至微团聚体中稳定，而新形成的小团聚体则富集新氮。作物种植期间小团聚体中肥料氮加速释放为作物供应氮素，其再形成过程又富集新氮，揭示了小团聚体在“供应氮素”与“富集氮素”方面的双重功能。最终，轮作通过重构土壤团聚体结构强化了这一过程，显著增加了土壤氮库。与连作相比，轮作系统下肥料氮储量提升27.11%−111.68%，全氮储量增加2.94%−14.22%。本研究阐明了土壤团聚体功能异质性作为长期肥料氮固持与稳定的关键机制，为优化轮作系统下的氮素管理提供了理论依据。

Abstract:

Soil aggregates highly regulate nitrogen (N) turnover, yet their functions in regulating N retention under long-term crop rotation remain unclear.  This study used 15N-labeled fertilizer N to investigate how different-sized soil aggregates regulate fertilizer N retention and redistribution under long-term crop rotation systems.  The results revealed that large macroaggregates exhibited a more pronounced depletion of fertilizer N (enrichment factor, Ef: 0.73−0.95) than of total N (Ef: 0.93−1.00).  In contrast, macroaggregates and microaggregates enriched fertilizer N (Ef: 1.00−1.16).  Crucially, we found a temporal divergence: after harvest (with new 15N-labeled fertilizer application), macroaggregates preferentially sequestered new N (current-season fertilizer N), whereas microaggregates dominated the stabilization of old N (previous-year fertilizer N) in the absence of 15N-labeled fertilizer in 2024.  This functional specialization is driven by aggregate turnover, whereby disintegrating macroaggregates release old N for stabilization in microaggregates, while reforming macroaggregates encapsulate new N.  The accelerated release of fertilizer N from these macroaggregates during crop cultivation supplies N to crops, while their reformation concurrently enriches new N.  This process underscores the dual functions of macroaggregates in both supplying N to crops and enriching new N.  Ultimately, crop rotations reinforce this beneficial dynamic by restructuring soil aggregation, leading to a marked expansion of the soil N pool, with fertilizer N storage increasing by 27.11−111.68% and total N storage by 2.94−14.22% compared to continuous cropping.  Our findings establish the functional heterogeneity of soil aggregates as a key mechanism for long-term fertilizer N retention and stabilization.  This provides a mechanistic basis for optimizing N management under crop rotations.

Key words: 15N-labeled fertilizer , long-term crop rotation , soil aggregates , aggregates function , nitrogen turnover