Evaluation of soil aggregate microstructure and stability under wetting and drying cycles in two Ultisols using synchrotron-based X-ray micro-computed tomography
文献类型：期刊论文
| 作者 | Ma, RM; Cai, CF; Li, ZX; Wang, JG; Xiao, TQ; Peng, GY; Yang, W |
| 刊名 | SOIL & TILLAGE RESEARCH
 |
| 出版日期 | 2015 |
| 卷号 | 149页码:1—11 |
| 关键词 | LEAST-SQUARES REGRESSION ORGANIC-MATTER PORE CHARACTERISTICS SIZE DISTRIBUTION TENSILE-STRENGTH SEDIMENT YIELD DYNAMICS SHRINKAGE EROSION METHODOLOGY |
| 英文摘要 | Soil structure and the soil pore system are important for many soil environmental processes. However, little is known about the influence of intra-aggregate microstructure on aggregate stability. The objective of this study was to evaluate the effect of soil pore characteristics on wet aggregate stability and aggregate tensile strength (TS) using synchrotron-based X-ray micro-computed tomography (SR-mu CT) under wetting and drying cycles. Undisturbed topsoils (200 cm(3)) derived from shale (S) and Quaternary red clay (Q) were submitted to three wetting and drying treatments under controlled laboratory conditions. 3-5 mm aggregates were collected from different treatments and scanned at 3.7 mu m voxel-resolution for the reconstruction of 3D micro tomography images. The wet aggregate stability and TS were measured after each treatment. The relationships among pore characteristics, wet aggregate stability, and TS were analyzed using partial least squares regression (PLSR). The results indicated that porosity (P), percentage of pores >100 mu m (Pd->100), and fraction of elongated pores (PEP) all significantly increased with an increasing number of wetting and drying cycles, while the opposite trends were observed for the total number of pores (TNP), the percentage of pores with a diameter of 75-100, 30-75, and <30 mu m. Decrease in wet aggregate stability and TS of both soils was mainly due to higher P, a more extensive and complex pore network, which caused increased air pressure, increased rate of water entry, and high probability of crack propagation and interaction. The TNP, Pd75-100, P, and Pd->100, were identified as the primary factors controlling the wet aggregate stability and TS according to PLSR. The pore characteristics and soil clay content accounted for as much as 99% of the variation in wet aggregate stability and TS. This study provides insights for improved understanding of the change in topsoil microstructure; however, the effect of pore characteristics on the aggregate breakdown mechanism requires further investigation. (C) 2015 Elsevier B.V. All rights reserved. |
| 收录类别 | SCI |
| 语种 | 英语 |
| 公开日期 | 2015-12-24 |
| 源URL | [http://ir.sinap.ac.cn/handle/331007/24455]  |
| 专题 | 上海应用物理研究所_中科院上海应用物理研究所2011-2017年 |
| 推荐引用方式 GB/T 7714 | Ma, RM,Cai, CF,Li, ZX,et al. Evaluation of soil aggregate microstructure and stability under wetting and drying cycles in two Ultisols using synchrotron-based X-ray micro-computed tomography[J]. SOIL & TILLAGE RESEARCH,2015,149:1—11. |
| APA | Ma, RM.,Cai, CF.,Li, ZX.,Wang, JG.,Xiao, TQ.,...&Yang, W.(2015).Evaluation of soil aggregate microstructure and stability under wetting and drying cycles in two Ultisols using synchrotron-based X-ray micro-computed tomography.SOIL & TILLAGE RESEARCH,149,1—11. |
| MLA | Ma, RM,et al."Evaluation of soil aggregate microstructure and stability under wetting and drying cycles in two Ultisols using synchrotron-based X-ray micro-computed tomography".SOIL & TILLAGE RESEARCH 149(2015):1—11. |
入库方式： OAI收割
来源：上海应用物理研究所
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