School of Life Sciences, Arizona State University, Tempe, Arizona, USA.
Center for Fundamental and Applied Microbiomics, The Biodesign Institute, Arizona State University, Tempe, Arizona, USA.
Appl Environ Microbiol. 2019 May 16;85(11). doi: 10.1128/AEM.02957-18. Print 2019 Jun 1.
The complex structural and functional responses of agricultural soil microbial communities to the addition of carbonaceous compounds such as biochar remain poorly understood. This severely limits the predictive ability for both the potential enhancement of soil fertility and greenhouse gas mitigation. In this study, we utilized shotgun metagenomics in order to decipher changes in the microbial community in soil microcosms after 14 days of incubation at 23°C, which contained soils from biochar-amended and control plots cultivated with Napier grass. Our analyses revealed that biochar-amended soil microbiomes exhibited significant shifts in both community composition and predicted metabolism. Key metabolic pathways related to carbon turnover, such as the utilization of plant-derived carbohydrates as well as denitrification, were enriched under biochar amendment. These community shifts were in part associated with increased soil carbon, such as labile and aromatic carbon compounds, which was likely stimulated by the increased available nutrients associated with biochar amendment. These findings indicate that the soil microbiome response to the combination of biochar addition and to incubation conditions confers enhanced nutrient cycling and a small decrease in CO emissions and potentially mitigates nitrous oxide emissions. The incorporation of biochar into soil is a promising management strategy for sustainable agriculture owing to its potential to sequester carbon and improve soil fertility. Expanding the addition of biochar to large-scale agriculture hinges on its lasting beneficial effects on the microbial community. However, there exists a significant knowledge gap regarding the specific role that biochar plays in altering the key biological soil processes that influence plant growth and carbon storage in soil. Previous studies that examined the soil microbiome under biochar amendment principally characterized only how the composition alters in response to biochar amendment. In the present study, we shed light on the functional alterations of the microbial community response 2 years after biochar amendment. Our results show that biochar increased the abundance of genes involved in denitrification and carbon turnover and that biochar-amended soil microcosms had a reduction in cumulative CO production.
农业土壤微生物群落对碳素化合物（如生物炭）添加的复杂结构和功能响应仍知之甚少。这严重限制了对土壤肥力的潜在增强和温室气体减排的预测能力。在这项研究中，我们利用高通量宏基因组学来破译在 23°C 下培养 14 天后土壤微生物群落的变化，这些土壤来自生物炭添加和对照小区种植的象草的土壤。我们的分析表明，生物炭添加的土壤微生物组在群落组成和预测代谢方面都发生了显著变化。与碳转化相关的关键代谢途径，如植物衍生碳水化合物的利用和反硝化作用，在生物炭添加下得到了富集。这些群落变化部分与土壤碳的增加有关，例如可利用的和芳香族碳化合物，这可能是由于生物炭添加带来的可用养分增加而刺激的。这些发现表明，土壤微生物组对生物炭添加和培养条件的组合的反应赋予了增强的养分循环和 CO 排放的小幅度减少，并且可能减少了氧化亚氮的排放。由于生物炭具有固碳和提高土壤肥力的潜力，因此将生物炭纳入土壤是可持续农业的一种有前途的管理策略。将生物炭的添加扩大到大规模农业取决于其对微生物群落的持久有益影响。然而，关于生物炭在改变影响植物生长和土壤碳储存的关键生物土壤过程方面所起的具体作用，仍存在显著的知识差距。以前研究生物炭添加对土壤微生物组的研究主要只描述了生物炭添加如何改变微生物组的组成。在本研究中，我们揭示了生物炭添加 2 年后微生物群落功能的变化。我们的结果表明，生物炭增加了参与反硝化和碳转化的基因的丰度，并且生物炭添加的土壤微宇宙的累积 CO 产量减少。
