Regulatory mechanism of bamboo biochar dosage on cadmium accumulation in Salix psammophila: insights from rhizosphere microbial communities, assembly processes, and interactions

作者：Xu Gai, Wenli Xing, Wanqing Cheng, Jiāng Xiǎo, Guangcai Chen · 发表于：Carbon Research · 年份：2024 · DOI：10.1007/s44246-024-00163-8 · 被引用次数：7 · 研究领域：Constructed Wetlands for Wastewater Treatment、Geochemistry and Elemental Analysis、Heavy metals in environment

Abstract Soil amendments play a pivotal role in regulating rhizosphere microbial communities, which is essential for maintaining robust plant growth under adverse environmental conditions. However, the microbial mechanisms that underlie the impact of biochar on phytoremediation performance remain incompletely understood in the context of different application rates. Here, we compared the phytoremediation performance, rhizosphere microbial community characteristics, and microbial interactions in Salix psammophila across different biochar application rates (1%, 3%, 5%, and 7%) in Cd-contaminated soil. Applying 5% biochar increased plant biomass by 10.02%, root activity by 183.82%, and Cd accumulation by 13.65%. Lower biochar rates (1% and 3%) decreased Cd accumulation in plants by 21.89% and 42.05%, respectively, compared to the control. Rhizosphere soil properties and Cd content, except for nitrogen, showed a gradient change with increasing biochar application rates. This was accompanied by an elevation in the Chao1 index for the bacterial community, although the fungal community remained unaffected in terms of diversity and structure. Null-model analyses indicated that fungal community assembly was mainly driven by ecological drift, explaining its unresponsiveness to biochar application. Applying 1% biochar enhanced microbial network stability while reducing bacterial network complexity. Conversely, 3% biochar application resulted in the lowest microbial network stability. Bi...