|
| 论文编号: |
|
| 论文题目: |
Molecular characterization of soil organic carbon in water-stable aggregate fractions during the early pedogenesis from parent material of Mollisols |
| 英文论文题目: |
Molecular characterization of soil organic carbon in water-stable aggregate fractions during the early pedogenesis from parent material of Mollisols |
| 第一作者: |
李娜 |
| 英文第一作者: |
N. Li |
| 联系作者: |
李娜，韩晓增 |
| 英文联系作者: |
N. Li，X. Z. Han |
| 外单位作者单位: |
|
| 英文外单位作者单位: |
|
| 发表年度: |
2020 |
| 卷: |
|
| 期: |
|
| 页码: |
|
| 摘要: |
Purpose The aims of this study were to investigate how short-term agricultural practices varying in vegetation cover, tillage, and organic amendments affected the chemistry of aggregate-associated C and particulate organic matter (POM) after 8-year soil restoration from parent material (PM) of a Mollisol. The research allowed indicating the effects of perennialization and organic amendments on the chemical compositions of soil organic carbon (SOC) in both aggregates and POM in short-term and thereof helped to unveil the mechanisms of C sequestration and stabilization. Material and methods The field surface soils (0-20 cm) under 8-year natural perennials and an arable soil with organic amendments were collected. Soil aggregate fractionation method was applied to obtain three aggregate-sized fractions: macroaggregate (> 250 mu m), microaggregate (53-250 mu m), and silt-clay unit (< 53 mu m). The coarse POM (cPOM, > 250 mu m), microaggregate (53-250 mu m), and silt-clay units within macroaggregate, the fine POM (fPOM, 53-250 mu m), and silt-clay units within microaggregate were further separated. In all, 10 subgroups of aggregates were obtained to determine organic carbon content and chemical structure using C-13-NMR spectroscopy technique. The PM for the establishment of the experiment was also used. Results and discussion The chemical composition of SOC differed among aggregate sizes, representing different organic compositions with different decomposition stages. Compared with PM, soil restoration under natural perennial and organic amendments increased SOC in both POM and aggregate fractions; higher proportion of POM with larger proportion of plant-derived O-alkyl C was observed in arable soil than in perennials. Meanwhile, the silt-clay units, sequestrating the most of the organic C, contained larger proportions of alkyl C, aromatic C, and carbonyl C, probably due to the microbial-derived by-products. The data partially supported our hypothesis that continuous organic amendments to PM likely promoted aggregate formation and subsequently affected the chemical composition of C therein. Conclusions Perennialization and organic amendments increased not only the total SOC stocks in bulk soils and aggregate fractions but also changed the SOM chemistry by varying quantity and quality of plant residues. The silt-clay units contributed largely to the stock and stability of SOC during the soil development stage from PM of a Mollisol. The main mechanisms of plant-derived C sequestrated and SOC accrued were controlled probably not only by the physiochemical protection of soil aggregates but also by the microbial C sequestration capacity in silt-clay fraction at the initial stage of soil formation. |
| 英文摘要: |
Purpose The aims of this study were to investigate how short-term agricultural practices varying in vegetation cover, tillage, and organic amendments affected the chemistry of aggregate-associated C and particulate organic matter (POM) after 8-year soil restoration from parent material (PM) of a Mollisol. The research allowed indicating the effects of perennialization and organic amendments on the chemical compositions of soil organic carbon (SOC) in both aggregates and POM in short-term and thereof helped to unveil the mechanisms of C sequestration and stabilization. Material and methods The field surface soils (0-20 cm) under 8-year natural perennials and an arable soil with organic amendments were collected. Soil aggregate fractionation method was applied to obtain three aggregate-sized fractions: macroaggregate (> 250 mu m), microaggregate (53-250 mu m), and silt-clay unit (< 53 mu m). The coarse POM (cPOM, > 250 mu m), microaggregate (53-250 mu m), and silt-clay units within macroaggregate, the fine POM (fPOM, 53-250 mu m), and silt-clay units within microaggregate were further separated. In all, 10 subgroups of aggregates were obtained to determine organic carbon content and chemical structure using C-13-NMR spectroscopy technique. The PM for the establishment of the experiment was also used. Results and discussion The chemical composition of SOC differed among aggregate sizes, representing different organic compositions with different decomposition stages. Compared with PM, soil restoration under natural perennial and organic amendments increased SOC in both POM and aggregate fractions; higher proportion of POM with larger proportion of plant-derived O-alkyl C was observed in arable soil than in perennials. Meanwhile, the silt-clay units, sequestrating the most of the organic C, contained larger proportions of alkyl C, aromatic C, and carbonyl C, probably due to the microbial-derived by-products. The data partially supported our hypothesis that continuous organic amendments to PM likely promoted aggregate formation and subsequently affected the chemical composition of C therein. Conclusions Perennialization and organic amendments increased not only the total SOC stocks in bulk soils and aggregate fractions but also changed the SOM chemistry by varying quantity and quality of plant residues. The silt-clay units contributed largely to the stock and stability of SOC during the soil development stage from PM of a Mollisol. The main mechanisms of plant-derived C sequestrated and SOC accrued were controlled probably not only by the physiochemical protection of soil aggregates but also by the microbial C sequestration capacity in silt-clay fraction at the initial stage of soil formation. |
| 刊物名称: |
Journal of Soils and Sediments |
| 英文刊物名称: |
Journal of Soils and Sediments |
| 论文全文: |
|
| 英文论文全文: |
|
| 全文链接: |
|
| 其它备注: |
|
| 英文其它备注: |
|
| 学科: |
|
| 英文学科: |
|
| 影响因子: |
|
| 第一作者所在部门: |
|
| 英文第一作者所在部门: |
|
| 论文出处: |
|
| 英文论文出处: |
|
| 论文类别: |
|
| 英文论文类别: |
|
| 参与作者: |
N. Li, J. H. Long, X. Z. Han, Y. R. Yuan and M. Sheng |
| 英文参与作者: |
N. Li, J. H. Long, X. Z. Han, Y. R. Yuan and M. Sheng |
|
 |
