李玉萍, 祝腾霄, 梅秀文, 张 鑫, 唐 婷, 李双异, 安婷婷, 汪景宽. 连续外源碳添加对土壤有机碳组分的影响[J]. 土壤通报, 2024, 55(4): 974 − 981. DOI: 10.19336/j.cnki.trtb.2024020202
引用本文: 李玉萍, 祝腾霄, 梅秀文, 张 鑫, 唐 婷, 李双异, 安婷婷, 汪景宽. 连续外源碳添加对土壤有机碳组分的影响[J]. 土壤通报, 2024, 55(4): 974 − 981. DOI: 10.19336/j.cnki.trtb.2024020202
LI Yu-ping, ZHU Teng-xiao, MEI Xiu-wen, ZHANG Xin, TANG Ting, LI Shuang-yi, AN Ting-ting, WANG Jing-kuan. Effects of Repeated Adding Exogenous Carbon on Soil Organic Carbon Fractions[J]. Chinese Journal of Soil Science, 2024, 55(4): 974 − 981. DOI: 10.19336/j.cnki.trtb.2024020202
Citation: LI Yu-ping, ZHU Teng-xiao, MEI Xiu-wen, ZHANG Xin, TANG Ting, LI Shuang-yi, AN Ting-ting, WANG Jing-kuan. Effects of Repeated Adding Exogenous Carbon on Soil Organic Carbon Fractions[J]. Chinese Journal of Soil Science, 2024, 55(4): 974 − 981. DOI: 10.19336/j.cnki.trtb.2024020202

连续外源碳添加对土壤有机碳组分的影响

Effects of Repeated Adding Exogenous Carbon on Soil Organic Carbon Fractions

  • 摘要:
    目的 农田生态系统中外源碳(根系分泌物、根残体等)会连续不断输入到土壤中,明确连续外源碳输入方式下土壤有机碳的形成和固定特征,为农田土壤固碳提供依据。
    方法 本研究以沈阳农业大学长期定位试验站不施肥处理表层(0 ~ 20 cm)土壤为研究对象,将13C标记葡萄糖以单次或连续多次(每隔15 d添加一次)的方式添加到土壤中,然后进行室内培养。分别在培养第14、29、57、100和365 d采样,通过分析土壤颗粒有机碳(POC)和矿物结合态有机碳(MAOC)组分中外源碳含量和贡献率,对比单次和连续添加方式对外源碳在土壤有机碳组分中分配的差异,探讨外源碳添加方式对土壤有机碳组分的影响。
    结果 单次和连续添加处理土壤MAOC中葡萄糖源碳含量分别在第100 d和第57 d达到最大值,然后随时间增加均呈降低趋势。第365 d,单次添加处理土壤POC和MAOC组分中葡萄糖源碳含量均为连续添加处理的1.50倍;连续添加处理土壤POC和MAOC中葡萄糖碳的贡献率分别为0.10%和0.57%,与单次添加处理相比分别降低了36.20%和31.75%(P < 0.05);单次和连续添加处理葡萄糖碳分配到MAOC的比例分别为14.69%和9.78%(P < 0.05)。
    结论 连续添加方式降低了稳定土壤有机碳的形成,单次添加方式的土壤有机碳固存潜力可能被高估。

     

    Abstract:
    Objective Exogenous carbon (C), such as root exudates and residues, is continuously input into soils under the farmland ecosystem. Research on the formation and fixation characteristics of soil organic C (SOC) after the repeated input of exogenous C into soil would provide a basis for soil C sequestration in farmland.
    Method In this study, the topsoil (0-20 cm) samples were collected from the plots of no fertilization at the long-term experimental station of Shenyang Agricultural University. The 13C-labeled glucose was added to the soil samples as a single or repeated (once every 15 days) way, and then they were incubated in the laboratory. The sub-samples were collected at the 14th, 29th, 57th, 100th and 365th days of incubation. The contents of particulate organic C (POC) derived from glucose C and that of mineral- associated organic C (MAOC) derived from glucose C were determined and their contribution percentages in these fractions were calculated, in order to differentiate the distribution of exogenous C in SOC fractions between single and repeated additions.
    Result The content of MAOC derived from glucose C reached the maximum value at the 57th day and the 100th day under the single and repeated ways, respectively, and then it decreased with incubation time. At the 365th day, the contents of glucose C derived-POC and glucose C derived- MAOC under the single addition way were 1.50 times those under the repeated addition way; The contribution percentage of glucose C derived-POC in POC and that of glucose C derived-MAOC in MAOC under the repeated addition way were 0.10% and 0.57%, respectively. And they were decreased by 36.20% and 31.75% (P < 0.05) compared with single addition way, respectively. About 14.69% and 9.78% of glucose C was allocated to MAOC under the single and repeated ways (P < 0.05), respectively.
    Conclusion Repeated addition reduces the formation of exogenous C in SOC fractions, while single addition may overestimates the SOC sequestration potential.

     

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