State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
Sci Total Environ. 2022 Sep 15;839:156333. doi: 10.1016/j.scitotenv.2022.156333. Epub 2022 May 29.
Biochar has been regarded as an effective amendment for soil carbon sequestration and soil quality improvement. However, it remains unclear how pyrolysis temperature and biochar aging impact the responses of soil properties and CO emissions to biochar addition. Here, we investigated the effect of biochar on soil properties and CO emissions in a laboratory incubation using soils amended with/without fresh biochar produced at 300 (BC300), 450 (BC450), and 600 °C (BC600) and their corresponding naturally aged samples (aged in soil for 360 days). The results showed that biochar significantly increased soil total nitrogen (by 8-36%), available phosphorus (by 19-69%) and available potassium (by 1.5-4.2-fold) throughout the incubation. Both fresh and aged biochar promoted the formation of soil macroaggregate at the end of the incubation. Moreover, fresh and aged BC300 increased the soil dissolved organic matter (DOM) content, whereas for BC450 and BC600, at the beginning, the content of soil DOM was reduced, but the effects finally became insignificant. Generally, fresh biochar had no significant effect on soil enzyme activities and soil bacterial richness and diversity, but an inhibitory effect occurred in the aged samples. Both fresh and aged BC300 increased soil CO emissions, which was due to the biochar-induced increase in soil DOM content and enrichment of copiotrophic bacteria (Proteobacteria) as well as the decline of oligotrophic bacteria (Acidobacteriota). A significant decrease in soil CO emissions was observed after fresh BC450 and BC600 addition, owing to the biochar-induced decline in soil DOM content, while an opposite trend was found in aged samples, which could be attributed to the shift of the dominant soil phylum from Acidobacteriota to Proteobacteria. These findings enhance our understanding of biochar's potential to improve soil quality and sequester soil carbon.
生物炭被认为是一种有效的土壤固碳和土壤质量改良剂。然而，热解温度和生物炭老化如何影响土壤性质和 CO 排放对生物炭添加的响应仍不清楚。在这里，我们使用在 300°C（BC300）、450°C（BC450）和 600°C（BC600）下产生的新鲜生物炭和未添加新鲜生物炭的土壤进行了实验室培养，研究了生物炭对土壤性质和 CO 排放的影响，并用相应的自然老化样本（在土壤中老化 360 天）进行了补充。结果表明，在整个培养过程中，生物炭显著增加了土壤全氮（增加 8-36%）、有效磷（增加 19-69%）和有效钾（增加 1.5-4.2 倍）。新鲜和老化的生物炭都促进了土壤大团聚体的形成。此外，新鲜和老化的 BC300 增加了土壤溶解有机物质（DOM）的含量，而对于 BC450 和 BC600，在开始时，土壤 DOM 的含量减少，但最终影响变得不显著。一般来说，新鲜生物炭对土壤酶活性和土壤细菌丰富度和多样性没有显著影响，但在老化样本中则存在抑制作用。新鲜和老化的 BC300 均增加了土壤 CO 排放，这是由于生物炭诱导的土壤 DOM 含量增加和富营养细菌（变形菌门）的富集以及贫营养细菌（酸杆菌门）的减少所致。新鲜 BC450 和 BC600 添加后，土壤 CO 排放显著减少，这是由于生物炭诱导的土壤 DOM 含量下降所致，而在老化样本中则发现了相反的趋势，这可能是由于土壤优势门从酸杆菌门转变为变形菌门所致。这些发现增强了我们对生物炭改善土壤质量和固碳潜力的理解。
