ISSN 1000-3665 CN 11-2202/P

    接菌对煤矸石重构土层结构的水盐分布及苜蓿生长的影响

    Effect of inoculation on water and salt distribution and alfalfa growth of coal gangue reconstructed layer

    • 摘要: 西部露天煤矿区排土场生态修复面临水资源严重匮乏的制约,三层(生态层-涵水层-隔水层)海绵结构能够起到涵蓄水分促进植物生长的作用,同时也存在持续浇灌咸水导致土壤盐碱化的风险。煤矸石作为煤炭开采产生的主要伴生固废,可资源化利用作为充填材料来改变复合材料的结构与性能,但将煤矸石作为三层海绵结构材料并联合微生物复垦盐碱化土壤的潜力尚不清楚。研究旨在探究三层海绵结构中不同涵水层材料(沙土、煤矸石)与接种丛枝菌根真菌(Arbuscular mycorrhizal fungi,AMF)对土壤水盐分布及苜蓿生长的影响,采用室内模拟土柱试验方法,试验设置4组处理,分别为沙土涵水层未接菌(S-CK)、煤矸石涵水层未接菌(C-CK)、沙土涵水层接种AMF(S-AM)与煤矸石涵水层接种AMF(C-AM)。研究结果表明:(1)相较于S-CK处理,C-CK处理使表层土盐度降低了31.5%,使苜蓿地上部生物量增加了49.6%、地下部生物量增加了38.3%;(2)相较于C-CK处理,C-AM处理使苜蓿地上部生物量增加了3.8倍、地下部生物量增加2.5倍,使表层土盐度提高了24.7%,AMF促进了20~40 cm土层粗根系的发育;(3)煤矸石涵水层与接种AMF的协同作用,使生态层土壤含水率增加了16.5%,表层土盐度降低了14.5%,地上部生物量增加了4.1倍,地下部生物量增加了4.7倍。综合研究表明,煤矸石涵水层与接种AMF相结合可以营造适生的土壤水盐环境,有效降低土壤盐碱化风险。研究结果可为西部地区露天矿排土场生态修复与重建提供科学依据与技术支撑。

       

      Abstract: In the arid and semi-arid regions of western China, water scarcity and soil salinization pose significant constraints. These areas are also the primary sites for coal mining, where large amounts of coal gangue are generated during extraction occupying vast land resources, further exacerbating ecological degradation. Soil layer reconstruction and microbial remediation technologies are critical approaches for ecological restoration in mining dumps. However, the potential of coal gangue as a reconstructed soil layer material and its combined effects with microbial remediation remain unclear. This study investigated the impacts of different culvert layer materials (sandy soil and coal gangue) and Arbuscular mycorrhizal fungi (AMF) inoculation on soil water-salt distribution and alfalfa growth within a three-layer sponge structure (ecological layer-culvert layer - waterproof layer). Indoor soil column experiments were conducted with four treatments: sandy culvert layer without inoculation (S-CK), coal gangue culvert layer without inoculation (C-CK), sandy culvert layer with AMF inoculation (S-AM), and coal gangue culvert layer with AMF inoculation (C-AM), each with three replicates. Compared to the S-CK treatment, the C-CK treatment reduces surface soil salinity by 31.5%, while increasing alfalfa aboveground and belowground biomass by 49.6% and 38.3%, respectively. (2) Compared to the C-CK treatment, the C-AM treatment enhances aboveground and belowground biomass by 3.8-fold and 2.5-fold, respectively, but increased surface soil salt accumulation by 24.7%. AMF inoculation also promotes the development of coarse roots in the 20−40 cm soil layer. (3) The synergistic combination of coal gangue culvert layer and AMF inoculation increased soil moisture content in the ecological layer by 16.5%, reduces surface soil salinity by 14.5%, and elevates aboveground and belowground biomass by 4.1-fold and 4.7-fold, respectively. These findings demonstrate that the integration of coal gangue as a culvert layer with AMF inoculation creates a favorable soil water-salt environment, offering an effective strategy for mitigating salinization and promoting ecological restoration of open-pit mining dumps in western China.

       

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