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Wijesinghe, J. N.*; 小嵐 淳; 安藤 麻里子; 國分 陽子; 山口 紀子*; 佐瀬 隆*; 細野 衛*; 井上 弦*; 森 裕樹*; 平舘 俊太郎*
Geoderma, 374, p.114417_1 - 114417_10, 2020/09
被引用回数:10 パーセンタイル:50.63(Soil Science)Volcanic ash soils store a large amount of carbon as soil organic carbon (SOC) for a long term. However, the mechanisms of SOC accumulation in such soils remain unexplained. In the present study, we focused on SOC in a buried humic horizon of a volcanic ash soil, which formed between 5400 and 6800 yr BP. SOC was fractionated using a chemical fractionation method and the separated SOC fractions were characterized by C age, stable isotopic ratios of carbon and nitrogen, and chemical structure. Results showed that the SOC fractions differ in the degrees of biological transformation and mobility. However, generally the low mobility of all of the SOC fractions suggests that successive up-building accumulation of SOC contributes to the formation of thick humic horizon in the soil.
Wijesinghe, J.*; 小嵐 淳; 安藤 麻里子; 國分 陽子; 山口 紀子*; 佐瀬 隆*; 細野 衛*; 井上 弦*; 森 裕樹*; 平舘 俊太郎*
no journal, ,
Soil organic carbon (SOC) is generated from organic components by receiving biological and chemical transformations in soils. Volcanic ash soils store a large amount of carbon for a long term and therefore the mechanisms of SOC storage in such soils are of interest for the development of techniques for carbon sequestration in soils. In the present study, we focused on SOC in a buried volcanic ash soil layer formed between 6200 and 9400 yr BP. SOC was fractionated using a chemical fractionation method and analyzed for chemical structure and carbon and nitrogen isotopic compositions. Results showed that the separated SOC fractions differ largely in the chemical structure, extent of microbial transformation, C age, and stabilization processes.
Wijesinghe, J.*; 小嵐 淳; 安藤 麻里子; 國分 陽子; 山口 紀子*; 佐瀬 隆*; 細野 衛*; 井上 弦*; 森 裕樹*; 平舘 俊太郎*
no journal, ,
The movement of soil organic carbon is important for understanding the formation and distribution of carbon in deeper soil layers. In the present study, we estimate the rate of vertical translocation of humin, humic acid, and four fulvic acid fractions and their relationship with chemical structure determined by CPMAS C NMR analysis. The average rates of vertical translocation of humin and humic acid were 4 and 5 mm per century, while those of fulvic acid were generally around 10 mm per century. C age of humic asid and humin in all layers was similar to the soil formation age, indicating that they have poorly translocated downwards. The young C age of some fulvic acid fractions in some layers indicates the translocation of young carbon from upper layers.
平舘 俊太郎*; Wijesinghe, J. N.*; 小嵐 淳; 安藤 麻里子; 佐瀬 隆*; 細野 衛*; 井上 弦*; 森 裕樹*
no journal, ,
青森県三戸郡三戸町古屋敷の黒ボク土は、約1.1千年前に降下した十和田a、約2.7千年前に降下した十和田b、約6.1千年前に降下した十和田中掫軽石、約9.2千年前に降下した十和田南部軽石などが累積的に堆積しており、かつその保存状態も良好であることから、精度よく土壌C貯留速度を推定するための好材料である。本研究では、この土壌断面で報告されているC年代による較正暦年代値などに基づき、本土壌におけるC貯留速度を推定した。その結果、正味の土壌C貯留速度は、火山放出物堆積後約11007600年間はほぼ一定であり平均で約28kg C/ha/年であったが、最初の約1100年間のC貯留速度はこれより速かったと推定された。