| 引用本文: | 李子昂,金 鑫,金彦香.灌溉及雨养草地土壤水盐运移规律研究[J].灌溉排水学报,2026,45(1):105-113. |
| LI Ziang,JIN Xin,JIN Yanxiang.灌溉及雨养草地土壤水盐运移规律研究[J].灌溉排水学报,2026,45(1):105-113. |
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| 摘要: |
| 【目的】研究高寒干旱区雨养草地与灌溉草地土壤水盐运移差异化机制。【方法】基于柴达木盆地东北部典型雨养与灌溉草地2024年生长季的连续监测数据，采用多传感器协同观测获取逐层土壤水盐信息，并结合突变检验与相关分析方法，系统研究土壤水盐的时空演变特征及其对降水事件的响应差异。【结果】①雨养草地的平均土壤饱和度（Saturation, Sr）为50.87%，主要受降水量调控，而灌溉草地土壤饱和度长期保持较高水平，平均为91.89%；②生长季灌溉草地10~50 cm平均土壤含盐量为77.18 mg/kg，显著低于雨养草地土壤含盐量91.03 mg/kg，土壤盐分动态可划分为4个阶段（淋溶、趋稳、返盐、二次淋溶）；③灌溉削弱了降水对土壤水盐的调控作用；④降水对雨养草地的盐分淋洗效率（Salt Leaching Efficiency，SLE，平均为0.9 mg/（kg·mm））显著高于灌溉草地（平均SLE为0.5 mg/（kg·mm）），但淋溶效应具有短暂性。【结论】灌溉改变了土壤水盐运移的基本模式，降低了土壤盐分积累量，但也减弱了自然降水对盐分的调节能力。 |
| 关键词: 土壤水盐；降水；灌溉；柴达木盆地；草地生态系统 |
| DOI：10.13522/j.cnki.ggps.2025182 |
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| Difference in soil water and salt dynamics between irrigated and rainfed grasslands |
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LI Ziang, JIN Xin, JIN Yanxiang
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1. Qinghai Province Key Laboratory of Physical Geography and Environmental Process, College of Geographical Science,
Qinghai Normal University, Xining 810016, China; 2. Key Laboratory of Tibetan Plateau Land Surface Processes and Ecological Conservation (Ministry of Education), Qinghai Normal University, Xining 810016, China; 3. Academy of Plateau Science and Sustainability, People’s Government of Qinghai Province and Beijing Normal University, Xining 810016, China
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| Abstract: |
| 【Objective】Alpine arid regions are characterized by scarce precipitation and fragile ecosystems, where soil water-salt dynamics directly affect grassland productivity and ecological stability. While irrigation is critical to maintaining grassland sustainability in these regions, it also alters the natural pattern of soil water-salt transport. Understanding changes in soil water-salt transport due to irrigation is important for improving water resource management and grassland ecological protection. This paper presents the results of an experimental study on differences in soil water-salt transport between rain-fed and irrigated grasslands.【Method】The study was based on spatiotemporal change in soil water and salt measured continuously during the 2024 growing season in a typical rain-fed and an irrigated grassland in the northeastern Qaidam Basin. Combined with mutation tests and correlation analysis, the differences in spatiotemporal dynamics of soil water and salt and their responses to precipitation events in the two grasslands were analysed.【Result】①The average soil saturation in the rain-fed grassland was 50.87%, which was mainly regulated by precipitation, and that of the irrigated grassland was 91.89%. ②The average soil salinity in the 10-50 cm soil layer was 77.18 mg/kg in the irrigated grassland and 91.03 mg/kg in the rain-fed grassland. The temporal dynamics of soil salinity during the experimental period in both grasslands could be divided into four stages: leaching, stabilization, salt accumulation, and secondary leaching. ③Irrigation attenuated the effect of precipitation on soil water content and salinity. ④Salt leaching was transient. On average over the experimental period, salt leaching efficiency of the precipitation in the rain-fed grassland was 0.9 mg/(kg·mm), significantly higher than that of 0.5 mg/(kg·mm) in the irrigated grassland. 【Conclusion】Irrigation alters soil water-salt transport pattern in the alpine arid grasslands, which not only reduces salt accumulation but also dampens the regulatory effect of precipitation in soil salinity. These results can help develop ecological protection and improve water management of the grasslands in alpine arid regions. |
| Key words: soil water-salt; precipitation; irrigation; Qaidam Basin; grassland ecosystem |
