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中国农学通报 ›› 2025, Vol. 41 ›› Issue (27): 85-93.doi: 10.11924/j.issn.1000-6850.casb2025-0164

• 资源·环境·生态·土壤 • 上一篇    下一篇

黔南喀斯特地区旱地改造水田对土壤微生物残体碳积累的影响

蔡煜1,2(), 肖玖军1,2, 廖小锋2,3, 董艳艳1,2, 潘伯娟1,2, 谢元贵1,2()   

  1. 1 贵州科学院 贵州省山地资源研究所,贵阳 550001
    2 贵州省土地绿色整治工程研究中心,贵阳 550001
    3 贵州科学院贵州省植物园,贵阳 550004
  • 收稿日期:2025-02-27 修回日期:2025-06-23 出版日期:2025-09-25 发布日期:2025-10-07
  • 通讯作者:
    谢元贵,男,1982年出生,四川达州人,研究员,博士,研究方向:土地资源与生态修复。通信地址:550001 贵州省贵阳市云岩区陕西路1号 贵州科学院,E-mail:
  • 作者简介:

    蔡煜,女,1994年出生,贵州贵阳人,助理研究员,硕士,研究方向:土地资源与生态修复。通信地址:550001 贵州省贵阳市云岩区陕西路1号 贵州科学院,E-mail:

  • 基金资助:
    贵州省基础研究(自然科学)计划项目“旱地改造水田对农田碳效应的影响机理研究”(黔科合基础-ZK[2023]一般231); 贵州科学院青年基金项目“喀斯特耕地土壤有机碳演变特征及驱动因素研究”(黔科院J字[2025]12号); 贵州省基础研究(自然科学)计划项目“百里杜鹃采煤塌陷区水田犁底层重构障碍因子诊断及作用机理研究”(黔科合基础-ZK[2021]一般100); 贵阳市科技计划项目“黔中地区耕地提质改造关键技术集成创新与应用示范”(筑科合同[2023]6-2号); 贵州省科技支撑计划项目“基于近地高光谱成像遥感的山区耕地土壤养分快速检测与动态监测关键技术研究与示范”(黔科合支撑[2021]一般496); 贵州省科技支撑计划项目“贵州石灰岩矿采矿迹地植物生态修复竹种筛选与应用示范研究”(黔科合支撑[2023]一般048); 贵州省基础研究(自然科学)计划项目“基于‘退出时间’理论的梵净山植物—土壤微生物复合生态系统稳定性维持机理研究”(黔科合基础-ZK[2022]一般276)

Effects of Dryland-to-paddy Conversion on Soil Microbial Necromass Carbon Accumulation in Karst Area of Southern Guizhou

CAI Yu1,2(), XIAO Jiujun1,2, LIAO Xiaofeng2,3, DONG Yanyan1,2, PAN Bojuan1,2, XIE Yuangui1,2()   

  1. 1 Guizhou Province Institute of Mountain Resources, Guizhou Academy of Sciences, Guiyang 550001
    2 The Land Greening Remediation Engineering Research Center of Guizhou Province, Guiyang 550001
    3 Guizhou Botanical Garden, Guizhou Academy of Sciences, Guiyang 550004
  • Received:2025-02-27 Revised:2025-06-23 Published:2025-09-25 Online:2025-10-07

摘要:

微生物残体碳是土壤有机碳的重要且活跃的组分。近年来,为提升粮食产能,实施了大量的旱地改造水田工程,但旱地改造水田后土壤微生物残体碳的积累特征及影响机制尚不清楚。本研究以贵州省平塘县旱地改造水田工程为研究对象,系统分析了改造前后土壤理化性质、有机碳含量、微生物量碳和微生物残体碳的变化特征,探讨了旱地改造水田对微生物残体碳积累的影响。结果表明:旱地改造水田显著降低了土壤全氮、全磷、有效磷、碱解氮和速效钾含量,分别下降33.1%、28.3%、70.4%、41.0%、65.1%;旱地改造水田后土壤有机碳、微生物量碳、微生物残体碳显著下降,分别下降39.3%、29.8%、25.6%。然而,细菌残体碳对有机碳的贡献显著上升(50%)。相关性分析和随机森林模型预测发现,有效磷、微生物量碳、碱解氮、全氮、pH、有机碳是调控土壤微生物残体碳动态的关键驱动因子。偏最小二乘结构方程模型表明,旱地改造水田主要通过影响土壤理化性质,影响有机碳和微生物量碳含量,从而改变真菌残体碳和细菌残体碳的比例,最终调控微生物残体碳的积累。短期观测结果表明,旱地改造水田后土壤总有机碳、微生物量碳、微生物残体碳和部分理化性质显著下降。因此,在工程实施后的管理阶段,应着重关注并适当增加土壤养分,以促进稳定有机碳的积累。同时需进一步开展长期定位观测研究,为绿色土地整治工程实施和农业可持续管理提供科学依据。

关键词: 旱地改造水田, 土壤有机碳, 微生物残体碳, 影响机制

Abstract:

Microbial necromass carbon (MNC) is a crucial component of soil organic carbon (SOC). The conversion of large-scale dryland to paddy fields has been recently implemented to improve farmland quality and security. However, the accumulation patterns and underlying mechanisms of MNC following such conversions are still unclear. In this study, the paddy field reconstruction project in Pingtang County, Guizhou Province was taken as the research object. The changes of soil physicochemical properties, organic carbon content, microbial biomass carbon and microbial necromass carbon before and after the convertion were systematically analyzed, and the effect of paddy field reconstruction on the accumulation of microbial necromass carbon was discussed. Through analysis of soil physicochemical properties, SOC, total nitrogen (TN), total phosphorus (TP), available phosphorus (AP), alkali-hydrolyzable nitrogen (AN), available potassium (AK), microbial biomass carbon (MBC) and MNC, we elucidated conversion-induced impacts on MNC sequestration. The results showed dryland-to-paddy conversion significantly reduced the contents of TN, TP, AP, AN and AK by 33.1%, 28.3%, 70.4%, 41.0% and 65.1%, respectively. After dryland to paddy fields conversion, SOC, MBC and MNC significantly decreased, with reductions of 39.3%, 29.8%, and 25.6%, respectively. However, the relative contribution of bacterial necromass carbon (BNC) to SOC increased significantly by 50%. Correlation analysis and random forest modeling identified AP, MBC, AN, TN, pH and SOC as key drivers regulating MNC dynamics. Partial least squares structural equation modeling (PLS-SEM) revealed that dryland-to-paddy conversion primarily affected fungal and bacterial necromass carbon content through modifications in soil physicochemical properties, SOC, and MBC, thereby controlling MNC accumulation. Short-term observations indicated that dryland-to-paddy conversion significantly reduced SOC, MBC, MNC and several soil physicochemical properties. In the post-conversion management phase, it is necessary to increase soil nutrient inputs to promote the accumulation of stable organic carbon. Long-term monitoring is essential to generate robust scientific data for guiding sustainable land consolidation and improving agricultural management practices.

Key words: dryland-to-paddy conversion, soil organic carbon, microbial necromass carbon, influence mechanism