Quantitative relationship between organic carbon and geochemical properties in tropical surface and subsurface soils
Quantitative relationship between organic carbon and geochemical properties in tropical surface and subsurface soils
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DOI：
10.1007/s10533-021-00813-8
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发表时间：
2021-06-12
期刊：
影响因子：
4
通讯作者：
Funakawa, S.
中科院分区：
文献类型：
--
作者：
Ashida, K.;Watanabe, T.;Funakawa, S.
我们调查了热带表层和亚表层土壤的有机碳（SOC）储量和SOC与地球化学性质之间的定量关系，其中各种土壤地球化学性质的信息仍然有限。我们使用了来自印度尼西亚、泰国、喀麦隆和坦桑尼亚的178个地点的土壤样品作为热带土壤，并在日本的34个地点进行了比较。热带土壤是酸性的，在高降水量下形成。我们根据风化程度将土壤样品分为三组。采用相关分析和一元回归分析方法，对土壤有机碳与草酸盐提取态Al和Fe（Al-o + Fe-o）、焦磷酸盐提取态Al和Fe（Al-p + Fe-p）、粘粒+粉粒等地球化学性质进行了相关分析和回归分析。在亚表层土壤中，Al-o + Fe-o和Al-p + Fe-p与土壤有机碳呈显著正相关（r分别为0.79-0.85和0.58-0.85），且在风化程度为4-5级和5-8级的土壤中，土壤有机碳与这两种性质的定量关系基本相似。另一方面，没有很强的相关性与SOC或类似的风化组之间的定量关系，发现粘土+粉砂。在表层土壤中，Al-o + Fe-o和Al-p + Fe-p与土壤有机碳呈显著正相关（r分别为0.48-0.56和0.55-0.76），但由于大量的C输入，C与活性Al和Fe的比值较高。我们的研究结果突出了Al-o + Fe-o和Al-p + Fe-p在SOC储存中的重要性，无论风化程度如何，表层和亚表层土壤中的SOC比例都是相似的。
We investigated soil organic carbon (SOC) storage and the quantitative relationship between SOC and geochemical properties in tropical surface and subsurface soils, where information on various soil geochemical properties remains limited. We used soil samples from 178 sites in Indonesia, Thailand, Cameroon, and Tanzania as tropical soils and 34 sites in Japan as a comparison. The tropical soils were acidic, formed under high precipitation. We separated the soil samples into three groups based on the degree of weathering. We applied correlation and single regression analyses between SOC and geochemical properties including oxalate extractable Al and Fe (Al-o + Fe-o), pyrophosphate extractable Al and Fe (Al-p + Fe-p), and clay + silt. In the subsurface soils, Al-o + Fe-o and Al-p + Fe-p were strongly correlated with SOC (r = 0.79-0.85 and 0.58-0.85, respectively), and the quantitative relationships of SOC with these properties were similar in all the weathering groups (4-5 and 5-8, respectively). On the other hand, no strong correlation with SOC or similar quantitative relationships among the weathering groups were found for clay + silt. In the surface soils, Al-o + Fe-o and Al-p + Fe-p were correlated with SOC (r = 0.48-0.56 and 0.55-0.76, respectively), but the ratio of C to active Al and Fe was higher probably because of the large C input. Our results highlight the importance of Al-o + Fe-o and Al-p + Fe-p in SOC storage, of which the ratios to SOC are similar in each of the surface and subsurface soils regardless of the weathering degree.