Pedosphere 34(3): 620--630, 2024
ISSN 1002-0160/CN 32-1315/P
©2024 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Pore shrinkage capacity of Shajiang black soils (Vertisols) on the North China Plain and its influencing factors |
Yueming CHEN1,2, Zhongbin ZHANG1, Lei GAO1, Zichun GUO1, Peng XIONG1,3, Fahui JIANG3, Xinhua PENG1,2 |
1 State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China)
2 University of Chinese Academy of Sciences, Beijing 100049 (China)
3 Jiangxi Agricultural University, Nanchang 330045 (China) |
| ABSTRACT |
| Different pore sizes present different pore shrinkage capacities in a nonrigid soil. However, the shrinkage capacities of different pore sizes and their influencing factors are not clear. We aimed to quantify the shrinkage capacities of different pore sizes (large pores, > 50 μm; medium pores, 0.2–50 μm; fine pores, < 0.2 μm) and determine how soil properties impact soil shrinkage capacity at the regional scale. Two sampling transects from west to east (360 km long, 35 samples) and from north to south (190 km long, 29 samples) were selected to investigate soil shrinkage capacity and physicochemical properties of at 0–20 cm depth in the Vertisol (locally known as Shajiang black soil) region of the North China Plain. The results showed that soil total shrinkage capacity, indicated by the coefficient of linear extensibility (COLE), had a mean value of 0.041–0.051 in the west-east and north-south transects. Large pores had higher pore shrinkage index (PSI) values (0.103–0.109) than medium (0.077–0.096) and fine (0.087–0.091) pores. The PSI of fine pores showed a fluctuating increasing trend from northwest to southeast, and the fine pore shrinkage capacity determined the COLE (r2 = 0.789, P < 0.001). The PSI of large pores had a significant relationship with soil bulk density (r = 0.281, P < 0.05) and organic carbon (r = -0.311, P < 0.05), whereas those of medium and fine pores were correlated with soil clay content (r = 0.381 and 0.687, respectively, P < 0.001). In addition, the PSI of fine pores was also correlated with montmorillonite content (r = 0.387, P < 0.01). It can be concluded that the PSI of large pores is related to anthropogenically influenced soil properties with low stability, whereas those of medium and fine pores are related to pedogenic properties. The high variability in anthropogenic and pedogenic factors explains the spatial pattern of Vertisol shrinkage capacity on the North China Plain. |
| Key Words: clay content,coefficient of linear extensibility,pore shrinkage index,soil structure,spatial distribution,swelling |
| Citation: Chen Y M, Zhang Z B, Gao L, Guo Z C, Xiong P, Jiang F H, Peng X H. 2024. Pore shrinkage capacity of Shajiang black soils (Vertisols) on the North China Plain and its influencing factors. Pedosphere. 34(3): 620–630. |
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