Pedosphere (3): 569--579, 2025
ISSN 1002-0160/CN 32-1315/P
©2025 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Effects of deficit winter irrigation with overwintering freezing on oasis soil salinization and alkalization |
Xicai PAN1, Jiabao ZHANG1 , Yanfang ZHOU2, Chengwei WAN1 |
1 State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China);
2 Key Laboratory of the Special Medicine Source Plant for Germplasm Innovation and Safety Utilization, Gansu Academy of Agri-Engineering Technology, Wuwei 733006 (China) |
| ABSTRACT |
| Winter irrigation is a crucial measure for preventing farmland salinity in arid inland regions. However, given the relatively complex process of salt leaching under the influence of freezing and thawing, present salinity management has led to soil quality deterioration in the irrigation areas in Northwest China. To better understand this process, a field experiment was conducted in Huangyang Town, Wuwei City, Gansu Province, China to simulate the evolution of soil profile salinity and alkalinity in a typical oasis farmland under 3-year regular barley planting, using a local prevailing water-salt management mode of drip irrigation for the growing period and winter irrigation for the fallow period. This study investigated the impact of freezing on salt leaching by comparing the soil profile water, heat, and salt movements under different winter irrigation quotas. Compared to no winter irrigation, a reduction in the winter irrigation quota from the standard one to a halved one led to a transition from a sink of 11.05% by salt leaching to a source of 13.75% by salt addition. This means that overwintering soil freezing, especially in oases with deep groundwater tables, can worsen root zone salinization caused by a deficit winter irrigation, through freezing-induced root zone soil water and salt return. Furthermore, dry saline soil dominated by sulfate is at the risk of soil alkalization when freezing-induced oversaturation of solute concentration leads to significant salt precipitation. These findings are crucial for understanding the mechanisms behind the increasing secondary salinization caused by unsustainable winter irrigation in oasis irrigation areas. |
| Key Words: groundwater table|salt leaching|salt precipitation|secondary salinization|sodium adsorption ratio|total dissolved solid |
| Citation: Pan X C, Zhang J B, Zhou Y F, Wan C W. 2025. Effects of deficit winter irrigation with overwintering freezing on oasis soil salinization and alkalization. Pedosphere. 35(3): 569-579. |
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