| 摘要: |
| 【目的】为探究微咸水滴灌及改良材料配施对节水灌溉农田土壤盐分的影响规律，【方法】以内蒙古河套灌区典型重度盐碱地为对象，分别开展了常规灌溉、微咸水滴灌、微咸水滴灌配施生物炭和微咸水滴灌配施石膏四个处理的田间小区试验，对比分析了不同处理对于土壤盐分及其离子组成的调控效应。【结果】结果表明：微咸水滴灌的平均脱盐率（13.46%）大于常规黄灌（7.14%），不会造成显著的盐分积累，但土壤盐分中Na+、Cl-含量分别增加了91.13%和47.21%，全盐占比也随之增加，从而引起土壤钠质化后果，并导致土壤盐分在20~40cm土层积累；微咸水滴灌配施生物炭或石膏可提高土壤脱盐率并消减土壤钠质化危害，且以微咸水滴灌配施石膏处理脱盐率最高，可达到46.30%；相比于其他处理，微咸水滴灌配施生物炭表现出更为强烈的生育期土壤返盐现象，且土壤K+、Mg2+?SO42-的全盐占比有所提高，而微咸水滴灌配施石膏处理则会降低Na+、Cl-、Mg2+的全盐占比，提高Ca2+和SO42-的全盐占比?【结论】微咸水滴灌配施生物炭或石膏具有调控盐分运动与离子组成的双重效应，这为河套灌区盐碱地节水改良利用提供了一定理论基础? |
| 关键词: 微咸水滴灌、河套灌区、土壤盐分、离子组成、生物炭、石膏 |
| DOI： |
| 分类号:S156.4+1 |
| 基金项目:国家重点研发计划项目（2016YFC0501300，2016YFD0200303）；国家自然科学基金项目（U1806215，U1906221）；中国科学院科技服务网络计划（STS计划）课题（KFJ-STS-ZDTP-049，KFJ-STS-ZDTP-053） |
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| Effect of Amendment Materials on Soil Salt Distribution and Ion Composition in Brackish Water Drip Irrigation |
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zhengfule, yaorongjiang
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Institute of Soil Science, Chinese Academy of Sciences
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| Abstract: |
| 【Background】Due to the long-term unreasonable irrigation and drainage management practices, soil salinization and water shortage problem increasingly become the key factors which restrict the agriculture development and efficient utilization of water resources in the Hetao Irrigation District. Brackish water irrigation using underground brackish water resources is a prospective irrigation method for the prevention and control of soil salinization in Hetao Irrigation District. Adding a variety of amendment materials to the soil, as a convenient and inexpensive method, has found wide applications in soil salinization management. A lot of work has been devoted to the research on the change of soil salt under the condition of brackish water irrigation. However, most of the existing researches focus on the change of the total soil salt and crop yields, the change of soil salt ion composition have been rarely studied. Moreover, little research has been done on the combination of brackish drip irrigation and amendment materials. 【Objective】In order to explore the influence discipline of brackish irrigation and amendment materials application on soil salts transport in water-saving irrigation farmland. 【Method】A case study was performed on typical moderate and heavy saline soil in Hetao Irrigation District of Inner Mongolia, and a field plot experiment with four treatments were designed on the sunflower planting: (1) conventional flood irrigation; (2) brackish water drip irrigation; (3) brackish water drip irrigation＋biochar; (4) brackish water drip irrigation＋gypsum. Effects of different measures on soil salt content, ion composition were analyzed, respectively.【Result】The results pointed out that the average proportion rate of desalination under brackish water drip irrigation is 13.46%, which is higher than conventional irritation (7.14%). Salt accumulation was not observed under brackish water drip irrigation. However, in comparison with conventional irritation, the content of Na+ and Cl- under brackish water drip irrigation increased by 91.13% and 47.21%, resulting in the increase of proportion of NaCl (sodium chloride) in total soil salts. This also led to soil sodication and the accumulation of soil salinity in 20~40cm soil layer. Both brackish water drip irrigation with biochar and brackish water drip irrigation with gypsum enhanced the soil desalination rate, and reduced the hazard of soil sodication. Brackish water drip irrigation with gypsum got a higher soil desalination rate of 46.30%. Compared with other practices, the brackish water drip irrigation with biochar had stronger top enrichment of soil salinity during the sunflower growth period, and the proportion of K+, Mg2+, SO42- in total soil salts also increased. On the contrary, brackish water drip irrigation with gypsum decreased the proportion of Na+, Cl- and Mg2+, and increased the proportion of Ca2+ and SO42- in total soil salts. 【Conclusion】Brackish water irrigation coupled with amendment materials can not only regulate soil salinity dynamics, but also manage the ionic composition and even soil salinization types. In the application of brackish water drip irrigation, the combination of amendment materials such as biochar and gypsum can improve soil desalination rate, and eliminate the enrichment of soil sodium ions caused by brackish water drip irrigation. As a result, brackish water drip irrigation with biochar or with gypsum has the contributions to regulating the transport of soil salinity and the ionic composition of soil salinity. This study provided an important theoretical basis to improvement and utilization of saline-alkali soil and water-saving irritation in arid irrigated area. |
| Key words: brackish water drip irrigation, Hetao Irrigation District, soil salinity, ionic composition, biochar, gypsum |
