College of Resources and Environment, Northeast Agricultural University, Harbin, 150030, Heilongjiang, PR China.
College of Resources and Environment, Northeast Agricultural University, Harbin, 150030, Heilongjiang, PR China.
Environ Res. 2023 Jul 1;228:115895. doi: 10.1016/j.envres.2023.115895. Epub 2023 Apr 12.
Soil microbial communities are responsive to biochar application. However, few studies have investigated the synergistic effects of biochar application in the restoration of degraded black soil, especially soil aggregate-mediated microbial community changes that improve soil quality. From the perspective of soil aggregates, this study explored the potential microbial driving mechanism of biochar (derived from soybean straw) addition in black soil restoration in Northeast China. The results showed that biochar significantly improved the soil organic carbon, cation exchange capacity and water content, which play crucial roles in aggregate stability. The addition of biochar also significantly increased the concentration of the bacterial community in mega-aggregates (ME; 0.25-2 mm) compared with micro-aggregates (MI; <0.25 mm). Microbial co-occurrence networks analysis showed that biochar enhanced microbial interactions in terms of the number of links and modularity, particularly in ME. 16 S rRNA sequencing predicted that the expression of genes related to carbon (rbcL, acsA, gltS, aclB, and mcrA) and nitrogen (nifH and amoA) transformation increased after the addition of biochar. Furthermore, the functional microbes involved in carbon fixation (Firmicutes and Bacteroidetes) and nitrification (Proteobacteria) were significantly enriched and are the key regulators of carbon and nitrogen kinetics. Structural equation model (SEM) analysis further showed that the application of biochar promoted soil aggregates to positively regulate the abundance of soil nutrient conversion-related microorganisms, thereby increasing soil nutrient content and enzyme activities. These results provide new insights into the mechanisms of soil restoration through biochar addition.
土壤微生物群落对生物炭的应用有响应。然而，很少有研究调查生物炭在退化黑土恢复中的协同作用，特别是改善土壤质量的土壤团聚体介导的微生物群落变化。从土壤团聚体的角度出发，本研究探讨了生物炭（来源于大豆秸秆）添加在东北黑土恢复中的潜在微生物驱动机制。结果表明，生物炭显著提高了土壤有机碳、阳离子交换容量和含水量，这些因素对团聚体稳定性至关重要。与微团聚体（MI；<0.25mm）相比，生物炭的添加还显著增加了大团聚体（ME；0.25-2mm）中细菌群落的浓度。微生物共现网络分析表明，生物炭增强了微生物之间的相互作用，表现在连接数量和模块性方面，特别是在 ME 中。16S rRNA 测序预测，添加生物炭后与碳（rbcL、acsA、gltS、aclB 和 mcrA）和氮（nifH 和 amoA）转化相关的基因表达增加。此外，参与固碳（Firmicutes 和 Bacteroidetes）和硝化（Proteobacteria）的功能微生物明显富集，是碳氮动力学的关键调节剂。结构方程模型（SEM）分析进一步表明，生物炭的应用促进了土壤团聚体正向调节与土壤养分转化相关的微生物丰度，从而增加了土壤养分含量和酶活性。这些结果为通过生物炭添加促进土壤恢复的机制提供了新的见解。
