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中国农学通报 ›› 2026, Vol. 42 ›› Issue (17): 76-88.doi: 10.11924/j.issn.1000-6850.casb2026-0228

• 资源环境生态土壤气象 • 上一篇    下一篇

麦秆与棉秆生物炭对根际土壤硅形态转化及盐分离子动态的调控机制

胡天巧(), 王耀锋()   

  1. 新疆农业大学资源与环境学院/新疆土壤与植物生态过程重点实验室, 乌鲁木齐 830052
  • 收稿日期:2026-03-24 修回日期:2026-05-10 出版日期:2026-09-09 发布日期:2026-09-09
  • 通讯作者:
    王耀锋,男,1987年出生,陕西扶风人,副教授,博士,主要从事生物炭中元素的生物地球化学循环研究。通信地址:830052 新疆乌鲁木齐市沙依巴克区农大东路311号 新疆农业大学资源与环境学院新疆土壤与植物生态过程重点实验室,Tel:0991-8763041,E-mail:
  • 作者简介:

    胡天巧,女,2000年出生,河南开封人,在读硕士,研究方向:废弃物资源化利用。通信地址:830052 新疆乌鲁木齐市沙依巴克区农大东路311号 新疆农业大学资源与环境学院新疆土壤与植物生态过程重点实验室,Tel:0991-8763041,E-mail:

  • 基金资助:
    国家自然科学基金地区科学基金项目“生物炭对干旱区土壤-小麦系统硅营养和培肥抑盐的协同作用机制”(42367037)

Regulatory Mechanism of Wheat Straw and Cotton Stalk Biochar on Silicon Morphological Transformation and Salt Ion Dynamics in Rhizosphere Soil

HU Tianqiao(), WANG Yaofeng()   

  1. College of Resources and Environment, Xinjiang Agricultural University/ Key Laboratory of Soil and Plant Ecological Process, Urumqi 830052
  • Received:2026-03-24 Revised:2026-05-10 Published:2026-09-09 Online:2026-09-09

摘要:

为了探究不同硅含量的生物炭对根际盐渍化土壤的改良路径与机制,本研究通过盆栽试验,以小麦、棉花秸秆为原料,于300℃和500℃条件下制备了4种生物炭,分别标记为WS300、WS500、CS300、CS500,并以未添加生物炭的处理为对照(标记为CK),系统分析了生物炭对根际微环境、硅形态转化及离子吸收的影响。结果表明,麦秆生物炭(WS系列)在活性硅形态(如水溶态硅和无定形硅)的含量和离子释放能力上,显著优于棉秆生物炭(CS系列)。其中,300℃的低温热解更利于保留这些活性组分。WS300生物炭在小麦分蘖期快速释放盐分离子,显著提高了根际EC值,大幅增加了Na+、Cl-、K+、Ca2+含量,塑造了一个高盐启动微环境;至收获期,其有效态硅含量约为CS300的1.15倍、CS500的2.35倍。WS300生物炭多孔结构在培养后,表面Si含量富集而Cl、Ca含量下降,表明快速释盐与同步固硅的表面作用过程。相比之下,CS500生物炭结构致密,硅的有效性较低且释盐缓慢。WS500生物炭则通过降低分蘖期的Na/Cl比值、提升K/Na比值,并在扬花期维持Ca/Mg稳定,收获期保持最高的K/Na比,持续优化根际离子平衡。上述过程进一步表明,盐分释放与硅活化之间存在耦合关系。研究将不同生物炭的功能归纳为2个主导维度:WS300以其突出的高活性硅与高K/Na选择性为特征;CS500偏向于高盐分负载。综上,本研究明确了麦秆与棉秆生物炭在调控根际环境方面的差异化路径,为干旱盐渍区硅含量不同的生物炭进行定向设计和应用提供了理论依据。

关键词: 麦秆生物炭, 根际土壤, 硅形态转化, 盐分离子, K/Na比

Abstract:

This study was designed to investigate the pathways and mechanisms by which biochars with contrasting silicon contents ameliorate rhizosphere salinized soils. A pot experiment was established using wheat-straw (WS) and cotton-straw (CS) biochars pyrolyzed at 300℃ and 500℃, designated as WS300, WS500, CS300, and CS500, with a no-biochar treatment as the control (CK). The effects of these biochars on rhizosphere microenvironments, silicon speciation transformation, and ionic uptake were systematically assessed. The results revealed that WS-derived biochars consistently outperformed CS-derived counterparts in terms of labile silicon fractions (i.e., water-soluble and amorphous silicon) and ion-releasing capacity, with low-temperature (300℃) pyrolysis being more favorable for retaining these active constituents. Specifically, WS300 triggered a rapid efflux of salt ions at the tillering stage, substantially elevating rhizosphere electrical conductivity (EC) and concurrently increasing the concentrations of Na+, Cl-, K+, and Ca2+, thereby establishing a high-salt priming microenvironment. By the harvest stage, the available silicon content under WS300 treatment was approximately 1.15-fold and 2.35-fold higher than that under CS300 and CS500, respectively. Post-incubation characterization of WS300 biochar showed surface Si enrichment accompanied by decreased Cl and Ca levels, indicating a surface-mediated process wherein rapid salt release was coupled with concurrent silicon immobilization. In contrast, CS500 biochar, possessing a denser microstructure, exhibited lower silicon availability and slower salt release. WS500 biochar, however, continuously optimized rhizospheric ionic balance by reducing the Na/Cl ratio and elevating the K/Na ratio at tillering, maintaining Ca/Mg stability at flowering, and sustaining the highest K/Na ratio at harvest. These findings further suggest a synergistic coupling between salt liberation and silicon activation. The functional traits of the tested biochars were distilled into two dominant axes: WS300 was distinguished by its superior labile silicon content and high K/Na selectivity, whereas CS500 was characterized by high salt loading. Collectively, this work clarifies the divergent regulatory pathways of wheat-straw versus cotton-straw biochars in modifying rhizosphere environments, providing a theoretical basis for the targeted design and application of silicon-variable biochars in arid saline agricultural regions.

Key words: wheat straw biochar, rhizosphere soil, silicon morphological transformation, salt ions, K/Na ratio

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