| 引用本文: | 张通港,胡行路,罗 敏,等.微咸水离子组成对膜下滴灌土壤水盐分布和作物生长的影响[J].灌溉排水学报,2023,42(8):16-25. |
| ZHANG Tonggang,HU Xinglu,LUO Min,et al.微咸水离子组成对膜下滴灌土壤水盐分布和作物生长的影响[J].灌溉排水学报,2023,42(8):16-25. |
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| 摘要: |
| 微咸水灌溉是缓解旱区农业用水危机的主要途径之一，而微咸水中的离子组成特征影响着土壤性质进而影响作物生长。【目的】探讨不同阳离子组成微咸水对土壤理化性质和作物生长的影响。【方法】于2021年4—9月，在内蒙古河套灌区，以膜下滴灌的模式种植春玉米，开展微咸水灌溉田间定位试验。以当地地下水为对照（CK），向地下水中分别添加相同物质的量浓度（20 mmol/L）、不同类型氯化盐（NaCl、KCl、CaCl2、MgCl2），形成相近的电导率（EC）、而不同阳离子组成微咸水处理（分别标记为T1、T2、T3、T4），研究土壤结构特性变化、水盐运移过程和作物生长响应。【结果】①与CK相比，添加Na+（T1处理）后0~20 cm土层小孔隙数量和储水量显著增加，尤其在灌水较多的拔节期；而T3处理和T4处理小孔隙度比T1处理分别降低147.73%和132.01%，有利于土壤孔隙结构的发育和水分的运移，降低了表层土壤储水量。②与CK相比，T1、T2、T3处理和T4处理分别提升了作物根区0~60 cm土壤中Na+、K+、Ca2+、Mg2+物质的量浓度，除T1处理外，T2、T3处理和T4处理对应的K+、Ca2+、Mg2+物质的量浓度均显著高于CK。T1处理在作物根区表层土壤有明显积盐现象，其他处理无明显变化，相反T3处理和T4处理土壤盐分整体向膜外运移，T4处理更为明显。受灌溉水EC影响，根区土壤饱和浸提液电导率（ECe）均在3~4 dS/m内。③作物地上部器官离子量中K+量最高，Na+量最低且显著低于K+、Ca2+、Mg2+、Cl-量。Na+、K+、Cl-量均表现为叶<茎，Ca2+和Mg2+离子量表现为叶>茎。T1—T4处理作物产量均有所增加，其中T4处理产量最大，较CK提升17.33%。【结论】含有较多Na+的微咸水灌溉提高了土壤表层小孔隙度，影响了土壤水分下渗，造成表层土壤盐分积累，而较多的K+、Ca2+、Mg2+则减少了土壤表层小孔隙度，有利于表层盐分淋洗。微咸水灌溉下，相对于较多的Na+带来显著负面效应，灌溉水中适当物质的量浓度的K+、Ca2+、Mg2+均有助于提高作物产量。研究结果可为河套灌区地下微咸水的安全利用提供理论依据。 |
| 关键词: 孔隙度；水盐分布；阳离子；作物生长 |
| DOI：10.13522/j.cnki.ggps.2022576 |
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| The Impact of Ion Composition in Saline Water on Soil Salinity, Salt Distribution, and Crop Growth under Mulched Drip Irrigation |
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ZHANG Tonggang, HU Xinglu, LUO Min, WANG Chun,
YAN Sihui, CHENG Yu, LIANG Qing, FENG Hao, ZHANG Tibin
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1. College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling 712100, China;
2. Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, China;
3. Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, China
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| Abstract: |
| 【Objective】 Saline water has been used as a supplementary irrigation resource in most countries to sustain agricultural production. The purpose of this paper is to study the influence of ionic composition in saline water on soil properties and growth of corn under mulched drip irrigation.【Method】 The field experiment was conducted from April to September 2021 in the Hetao Irrigation District (HID) in Inner Mongolia. The saline water was created by adding different chloride salts: NaCl (T1), KCl (T2), CaCl2 (T3) and MgCl2 (T4) to fresh water. Irrigation with fresh underground water served as the control (CK). During each treatment, change in soil structure, transport of water and salt in soil, and crop growth were measured.【Result】① Compared to CK, T1 significantly increased the number of small pores in the top 0~20 cm soil layer. This had a detrimental impact on soil structure but increased its water storage, particularly during the jointing stage. Compared to CK, T3 and T4 reduced the small porosity by 147.73% and 132.01%, respectively, but increased permeability of the soil. ② Compared to CK, all treatments increased the concentrations of Na+, K+, Ca2+ and Mg2+ in the 0~60 cm soil layer. Except T1, other treatments increased the concentrations of K+, Ca2+, and Mg2+, compared to CK. T1 resulted in salt accumulation in the soil surface, while other treatments did not show noticeable impact on ion composition. It was found that T3 and T4 moved the salt out the zone controlled by the mulch in the lateral direction, particularly T4. The electrical conductivity (EC) of the saturated extract from the root zone soil was influenced by the EC of irrigation water and varied in the range of 3~4 dS/m. ③ Na+ and K+ contents were the lowest and highest in the aboveground part, respectively. Na+, K+, and Cl- contents were higher in leaves than in stems, while Ca2+ and Mg2+ contents were higher in stem than in leaves. Increasing irrigation amount enhanced crop yield only in some treatments. Among all treatments, T4 gave the highest corn seed yield, 17.33% more than CK.【Conclusion】Irrigation with saline water containing high Na+ increased the small porosity of the topsoil, affecting soil water infiltration. In contrast, increasing K+, Ca2+, and Mg2+ contents reduced small porosity, promoting salt leaching due to the increased soil permeability. Keeping concentration of K+, Ca2+ and Mg2+ at appropriate levels under saline water irrigation is beneficial to increasing dry matter accumulation and the final yield, as it offsets the negative effects of excessive Na+. These findings provide guidance for safe utilization of saline water for irrigation in HID. |
| Key words: porosity; water and salt distribution; cation; corn growth |
