土壤微生物对秸秆碳转化及碳积累特征的Meta分析

Meta-Analysis of Carbon Conversion and Carbon Accumulation Characteristics of Soil Microorganisms on Straw

土壤有机碳是土壤的主要组成成分,其微小变化能够对陆地碳库和全球气候变化产生重大影响。利用Meta整合分析法分析微生物介导的秸秆碳转化和稳定机制,并阐明各类因素对土壤有机碳的影响。Meta分析结果显示,秸秆还田后土壤有机碳(SOC)、可溶性有机碳(DOC)和微生物量碳(MBC)含量分别增加了23.84%、10.94%和20.13%。土壤微生物能够显著影响秸秆还田下有机碳含量,真菌残体碳贡献率和细菌残体碳贡献率分别达到33.12%和14.80%。当还田秸秆类型为玉米秸秆,土壤类型为碱性土壤,气温高于25℃时,土壤有机碳累积效果最佳。土壤中的化学生物保护机制也可增加土壤有机碳含量,从而利于有机碳的固存,使土壤产生激发效应,刺激微生物生长代谢,从而形成微生物碳泵,令有机碳在土壤中处于动态平衡。对于农业生产来说,最重要的土壤功能是维持作物生产力、养分转化以及微生物丰度和活性的维持,应优先考虑这些功能,以维持土壤有机碳含量。

Soil organic carbon(SOC)is a major component of soil,and its small changes will have a significant impact on terrestrial carbon pools and global climate change.Meta-integration analysis was used to analyze the mechanism of microbial-mediated carbon transformation and stabilization in straw and to elucidate the effects of various factors on soil organic carbon.Meta-analysis results showed that soil organic carbon(SOC),soluble organic carbon(DOC)and microbial carbon(MBC)content increased by 23.84%,10.94%and 20.13%,respectively,after straw was returned to the field,and the soil microorganisms significantly affected the organic carbon content of straw.Content of organic carbon under field return,and the difference between the carbon contribution of fungal and bacterial residues reached 33.12%and 14.80%.The best effect of soil organic carbon accumulation was achieved when the type of returned stover was maize stover,the soil type was alkaline soil,and the temperature was higher than 25℃.The chemical-biological protection mechanism in the soil can also increase the soil organic carbon content,which is conducive to the sequestration of organic carbon,so that the soil produces an excitation effect to stimulate the growth and metabolism of microorganisms,thus forming a microbial carbon pump,so that the organic carbon is in a dynamic equilibrium in the soil.For agricultural production,the most important soil functions are the maintenance of crop productivity,nutrient transformation,and the maintenance of microbial abundance and activity,which should be prioritized in order to maintain soil organic carbon content.