Journal of Integrative Agriculture ›› 2025, Vol. 24 ›› Issue (4): 1542-1561.DOI: 10.1016/j.jia.2024.09.026

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秸秆还田通过改善土壤团聚体结构且不增加土壤异养呼吸从而提高土壤碳库

  

  • 收稿日期:2024-03-20 接受日期:2024-08-09 出版日期:2025-04-20 发布日期:2025-03-18

Crop straw incorporation increases the soil carbon stock by improving the soil aggregate structure without stimulating soil heterotrophic respiration

Hongyu Lin1, 2*, Jing Zheng1*, Minghua Zhou1#, Peng Xu1, Ting Lan3, Fuhong Kuang1, Ziyang Li1, 2, Zhisheng Yao4, Bo Zhu1   

  1. 1 Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China

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

    3 College of Resources, Sichuan Agricultural University, Chengdu 611130, China

    4 State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China

  • Received:2024-03-20 Accepted:2024-08-09 Online:2025-04-20 Published:2025-03-18
  • About author:Hongyu Lin, Mobile: +86-15683415241, E-mail: linhongyu17@mails.ucas.ac.cn; Jing Zheng, Mobile: +86-18224042294, E-mail: zhjing@imde.ac.cn; #Correspondence Minghua Zhou, Mobile: +86-15208257481, E-mail: mhuazhou@imde.ac.cn * These authors contributed equally to this study.
  • Supported by:
    This research was financially supported by the National Key Research and Development Program of China (2023YFD1901200), the National Natural Science Foundation of China (U22A20562), the Sichuan Science and Technology Program, China (2022YFS0500), the Project of Special Research Assistant of the Chinese Academy of Sciences (Jing Zheng), the China Postdoctoral Science Foundation (2022M723079), the Sichuan Provincial Postdoctoral Research Foundation, China (TB2022042) and the Science and Technology Research Program of Institute of Mountain Hazards and Environment, Chinese Academy of Sciences (IMHE-ZYTS-08).

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摘要：

秸秆还田常被作为维持作物产量、提高土壤有机碳（SOC）储量以及改善土壤质量的推荐的农田管理方式之一。但不同秸秆还田方式对土壤有机碳储量的长期影响仍存在不确定性。为评估不同秸秆还田方式对土壤有机碳储量的影响，从2007年到2018年开展了一项长期试验，设置了四种处理：MW0（玉米-小麦轮作、无秸秆还田）、MW50（玉米-小麦轮作、50%秸秆粉碎还田）、MWb50（玉米-小麦轮作、50%秸秆就地焚烧后还田）、MF50（玉米-休耕、50%秸秆粉碎还田）。结果表明，经过十余年连续秸秆还田后，MW50、MWb50和MF50处理下的SOC储量分别显著增加了32.4%、12.2%和17.4%；而在MW0处理下，SOC储量在11年长期试验后显著减少了22.9%。与MW0相比，秸秆还田显著增加了有机碳输入，改善了土壤团聚体结构，提高了溶解性有机碳（DOC）与颗粒性有机碳（POC）的比例，但土壤气态碳流失（土壤异养呼吸）并未显著增加，因此秸秆还田能显著提升SOC积累速率和土壤SOC储量。DOC与微生物量碳（MBC）比例的增加、酸杆菌门和变形菌门相对丰度的提高以及拟杆菌门和绿弯菌门相对丰度的降低，是秸秆还田下土壤异养呼吸无显著增加甚至减少的主要原因。根据Rothamsted Carbon（RothC）模型模拟结果，SOC储量在未来将达到平衡，MW50处理下的C储量平衡值最高，为18.85 Mg ha-1。总的来说，田间试验（2007-2018）和RothC模型模拟的结果表明，长期来看，在亚热带山地石灰性土壤中，玉米-小麦轮作且50%秸秆粉碎还田（MW50）对SOC储量增益优于其他秸秆还田处理。

Abstract:

Crop straw incorporation is widely recommended to maintain crop yields and improve soil organic carbon (SOC) stocks as well as soil quality.  However, the long-term effects of different straw incorporation practices on the SOC stock remain uncertain.  In this study, a long-term experiment (2007 to 2018) with four treatments (MW0: maize–wheat rotation with no straw incorporation, MW50: maize–wheat rotation with 50% chopped straw incorporation, MWb50: maize–wheat rotation with 50% in situ burned harvested straw, and MF50: maize–fallow rotation with 50% harvested maize straw incorporation) was set up to evaluate the response of the SOC stock to different straw incorporation methods.  The results showed that the SOC stock significantly increased by 32.4, 12.2 and 17.4% under the MW50, MWb50 and MF50 treatments, respectively, after continuous straw incorporation over a decade, while the SOC stock under MW0 was significantly reduced by 22.9% after the 11 year long-term experiment.  Compared to MW0, straw incorporation significantly increased organic carbon input, and improved the soil aggregate structure and the ratio of dissolved organic carbon (DOC) to particulate organic carbon (POC), but it did not significantly stimulate soil heterotrophic respiration, resulting in the increased SOC accumulation rate and SOC stocks of bulk soil.  The increased ratio of DOC to microbial biomass carbon (MBC) enhanced the relative abundances of Acidobacteria and Proteobacteria but inhibited Bacteroidetes and Chloroflexi, and the bacterial relative abundances were the main reasons for the non-significant increase or even decrease in soil heterotrophic respiration with straw incorporation.  The SOC stock would reach an equilibrium based on the results of Rothamsted carbon (RothC) model simulations, with a long-term equilibrium value of 18.85 Mg ha–1 under MW50.  Overall, the results of the long-term field experiment (2007–2018) and RothC model simulation suggested that maize–wheat rotation with 50% chopped straw incorporation delivered the largest benefits for the SOC stock in calcareous soils of subtropical mountain landscapes over the long term.


Key words: soil organic carbon , crop straw ,  soil aggregate ,  soil heterotrophic respiration ,  RothC model