| 引用本文: | 杨 武,王炳亮,陈淑娟,等.银北灌区冻融条件下农田土壤水盐运移特征[J].灌溉排水学报,2025,44(8):136-147. |
| YANG Wu,WANG Bingliang,CHEN Shujuan,et al.银北灌区冻融条件下农田土壤水盐运移特征[J].灌溉排水学报,2025,44(8):136-147. |
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| 摘要: |
| 【目的】研究冻融和冬灌条件下土壤水盐再分布规律及不同冬灌水量保墒洗盐效果，为提高盐碱地农业生产力和节约冬灌水量提供科学依据。【方法】以宁夏石嘴山市惠农区中度盐渍土为对象，对不同条件下的盐渍土开展冻融试验。未冬灌条件下，设置不同冷端温度（-13、-18、-23 ℃）和不同初始含水率试验（16%、19.5%、23%）；冬灌条件下，设置不同灌水量（室内冬灌水量：900、1 600、3 120 m3/（hm2·次），农田冬灌水量：3 120、3 510、3 900 m3/（hm2·次））。基于以上条件进行室内和农田冻融模拟试验，结合实测气象及土壤理化指标数据，采用统计分析及可视化方法对比分析不同条件下的土壤水盐运移规律。【结果】①冻结前期，土壤水分受表面温度的影响大，冻结锋面迁移速率较快，水分迁移量较小；冻结后期，土壤水分受表面温度的影响小，冻结锋面迁移速率较慢，水分迁移量较大。②水分的迁移对盐分的影响较为显著，但二者并非完全同步，盐分变化存在一定的滞后性，不同条件下的盐分在冻结锋面附近均存在数值陡增。③室内冬灌水量为900、1 600、3 120 m3/（hm2·次）条件下，盐分最大累积深度分别为35、55 cm和95 cm；相同冬灌水量的农田相同区域不存在盐分累积现象，且3 120、3 510、3 900 m3/（hm2·次）3种冬灌水量下的农田土壤翌年返潮期表现为相似的地力特征。【结论】未冬灌和冬灌状态具有明显的水盐运移差距，冬灌状态返盐明显，同时农田试验区冬灌具有一定的节水空间。 |
| 关键词: 银北灌区；冬灌；季节性冻融；水盐运移 |
| DOI：10.13522/j.cnki.ggps.2024358 |
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| Effects of freeze-thaw cycles and winter irrigation on soil water and salt transport in irrigation districts in Northern Yinchuan |
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YANG Wu, WANG Bingliang, CHEN Shujuan, LI Wangcheng, LIN Xing
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1. School of Civil and Hydraulic Engineering, Ningxia University, Yinchuan 750000, China; 2. Engineering Research Center for Efficient Utilization of Modern Agricultural Water Resources in Arid Areas, Ministry of Education, Yinchuan 750000, China;
3. Ningxia Key Laboratory of Digital Water Control of Yellow River Water Networking, Yinchuan 750000, China;
4. Service Center of Shizuishan Agricultural Technology Extension Center, Shizuishan 753000, China
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| Abstract: |
| 【Objective】In saline-alkali regions of Northern Yinchuan, freeze-thaw cycles and winter irrigation play a key role in soil water and salt dynamics. This paper experimentally studies how different winter irrigation amounts affect soil water and salt redistribution during freeze-thaw periods, aiming to improve water use efficiency and soil salt management.【Method】Freeze-thaw experiments were conducted in both laboratory and field using moderately saline-alkali soil, with soil in the former taken from Huinong District, Shizuishan City, Ningxia Province. The experiments investigated water and salt migration in soils under ① different freezing temperatures ranging from -13?℃ to -23?℃, ② different initial soil moisture contents ranging from 16% to 23%, and ③ different winter irrigation amounts ranging from 900 to 3 120?m3/hm2 in the laboratory, and from 3 120 ?to 3 900?m3/hm2 in the field. 【Result】① In the early freezing period, soil water was greatly affected by the surface temperature, and the migration rate of the freezing front was fast while liquid water migration was slow. In the late freezing period, soil water was not significantly affected by the surface temperature, and the migration rate of the freezing front was slow while liquid water migration was fast. ② Water migration significantly affected soil salinity, but the two did not occur simultaneously. There was a delay in salinity change following soil water change; soil salt content peaked in the vicinity of the freezing front. ③ In the laboratory experiments, the maximum salt concentration occurred at the depth of 35?, 55 and 95?cm, when irrigation amount was 900, 1 600 and 3 120??m3/hm2, respectively. In the field experiment, there was no salt accumulation under different irrigation amounts, and soil fertility in the following year was similar under different irrigation treatments.【Conclusion】Winter irrigation alters soil water and salt migration significantly, compared to treatment without irrigation. Winter irrigation results in salt leaching; our results suggest that optimizing winter irrigation amount is important to achieve water saving without compromising soil fertility. |
| Key words: Yinbei irrigation district; farmland winter irrigation; seasonal freeze-thaw; water and salt migration |
