Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing 210095, China.
Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095, China; Zhejiang Provincial Key Laboratory of Carbon Cycling in Forest Ecosystems and Carbon Sequestration, School of Environmental and Resource Sciences, Zhejiang A & F University, Lin'an, Hangzhou 311300, China.
Sci Total Environ. 2016 Nov 15;571:206-17. doi: 10.1016/j.scitotenv.2016.07.135. Epub 2016 Jul 27.
While numerous studies both in laboratory and field have showed short term impacts of biochar on soil microbial community, there have been comparatively few reports addressing its long term impacts particular in field condition. This study investigated the changes of microbial community activity and composition in a rice paddy four years after a single incorporation of biochar at 20 and 40t/ha. The results indicated that biochar amendment after four years increased soil pH, soil organic C (SOC), total N and C/N ratio and decreased bulk density, particularly for the 40t/ha treatment compared to the control (0t/ha). Though no significant difference was observed in soil basal respiration, biochar amendment increased soil microbial biomass C and resulted in a significantly lower metabolic quotient. Besides, dehydrogenase and β-glucosidase activities were significantly decreased under biochar amendment relative to the control. The results of Illumina Miseq sequencing showed that biochar increased α-diversity of bacteria but decreased that of fungi and changed both bacterial and fungal community structures significantly. Biochar did not change the relative abundances of majority of bacteria at phylum level with the exception of a significant reduction of Actinobacteria, but significantly changed most of bacterial groups at genus level, particularly at 40t/ha. In contrast, biochar significantly decreased the relative abundances of Ascomycota and Basidiomycota by 11% and 66% and increased the relative abundances of Zygomycota by 147% at 40t/ha compared to the non-amended soil. Redundancy analysis (RDA) indicated that biochar induced changes in soil chemical properties, such as pH, SOC and C/N, were important factors driving community composition shifts. This study suggested that biochar amendment may increase microbial C use efficiency and reduce some microorganisms that are capable of decomposing more recalcitrant soil C, which may help stabilization of soil organic matter in paddy soil in long term.
尽管许多实验室和野外研究都表明生物炭对土壤微生物群落有短期影响，但长期影响特别是在野外条件下的报道相对较少。本研究调查了在单施生物炭 20 和 40t/ha 四年后，水稻田土壤微生物群落活性和组成的变化。结果表明，与对照（0t/ha）相比，四年来生物炭的添加增加了土壤 pH、土壤有机碳（SOC）、总氮和 C/N 比，降低了容重，特别是在 40t/ha 处理下。尽管土壤基础呼吸没有显著差异，但生物炭的添加增加了土壤微生物生物量 C，导致代谢商显著降低。此外，与对照相比，生物炭的添加降低了脱氢酶和β-葡萄糖苷酶的活性。Illumina Miseq 测序结果表明，生物炭增加了细菌的α多样性，但降低了真菌的多样性，并显著改变了细菌和真菌的群落结构。生物炭没有改变大多数细菌门的相对丰度，除了放线菌的丰度显著降低，但显著改变了大多数细菌属的相对丰度，特别是在 40t/ha。相比之下，生物炭显著降低了有丝真菌门和担子菌门的相对丰度，分别为 11%和 66%，并将接合菌门的相对丰度增加了 147%，而在未添加土壤中，接合菌门的相对丰度增加了 147%。冗余分析（RDA）表明，生物炭引起的土壤化学性质变化，如 pH、SOC 和 C/N，是驱动群落组成变化的重要因素。本研究表明，生物炭的添加可能会提高微生物对 C 的利用效率，减少一些能够分解更难分解的土壤 C 的微生物，这可能有助于长期稳定稻田土壤中的有机物质。
