Phosphoric Acid and Magnesium Chloride Composite-Modified Biochar Improved Pakchoi Growth by Reducing Pb and Cd Accumulation and Altering Soil Properties and Microbial Communities
Soil heavy-metal pollution is one of the most serious environmental issues in the world. There is an urgent need to develop feasible strategies for the remediation of polluted soil. Biochar has great potential to reduce heavy metal phytotoxicity and promote plant growth, but its mechanisms are still...
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| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-06-01
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| Series: | Horticulturae |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2311-7524/11/6/632 |
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| Summary: | Soil heavy-metal pollution is one of the most serious environmental issues in the world. There is an urgent need to develop feasible strategies for the remediation of polluted soil. Biochar has great potential to reduce heavy metal phytotoxicity and promote plant growth, but its mechanisms are still unclear. In this study, phosphoric acid and magnesium composite-modified tea branch biochar (PMB) was prepared and characterized. The effects of PMB at 5% addition on pakchoi growth, Cd/Pb accumulation and subcellular distribution in pakchoi, soil physicochemical characteristics and enzyme activities, Cd/Pb bioavailability, bacterial community structure, and diversity in Cd/Pb co-contaminated soils was investigated by a pot experiment. The results showed that PMB significantly alleviated the phytotoxicity of Cd and Pb. The application of PMB effectively increased the plant height and biomass and Cd and Pb proportion in the cell wall, while reducing Cd and Pb accumulation and their distribution in cytoplasm and organelles in pakchoi plants. PMB significantly improved the activities of urease, invertase, and catalase and reduced the available Cd and Pb contents in soil. Moreover, PMB changed the structure and diversity of the soil bacterial community. The relative abundance of several beneficial microbial phyla, including <i>Acidobacteriota</i>, <i>Bacteroidota, Actinobacteriota</i>, and <i>Gemmatimonadota,</i> increased by 13.81%, 19.02%, 68.09%, and 34.79%, respectively. The Shannon and Chao1 index also increased significantly. This study provides an effective strategy for simultaneous Cd and Pb immobilization in soil, promoting plant growth and inhibiting heavy metal accumulation in vegetables, which highlights the application of PMB in sustainable agro-ecosystems. |
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| ISSN: | 2311-7524 |