| 摘要: |
| 【目的】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，分别开展了常规黄溉、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4个处理的田间小区试验，对比分析不同处理对于土壤盐分及其离子组成的效应?【结果】微咸水滴灌的平均脱盐率（13.46%）大于常规黄河水灌溉（7.14%），不会造成显著的盐分积累，但土壤盐分中Na+、Cl-量分别增加了91.12%和47.21%，全盐占比也随之增加，从而引起土壤钠质化，并导致土壤盐分在20~40 cm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：10.13522/j.cnki.ggps.2019200 |
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| The Effects of Soil Amendment with Different Materials on Soil Salt Distribution and Its Ion Composition under Brackish-water Drip Irrigation |
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ZHENG Fule, YAO Rongjiang, YANG Jingsong, WANG Xiangping, CHENG Qiang, LI Hongqiang
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1.State Key Laboratory of Soil and Sustainable Agriculture/Institute of Soil Science, Chinese Academy of Sciences,Nanjing 210008, China；2. University of Chinese Academy of Sciences, Beijing 100049, China; 3. Dongtai Institute of Tidal Flat Research, Nanjing Branch of Chinese Academy of Sciences, Dongtai 224200, China; 4. Centre of Agricultural and AnimalHusbandry Technology Extension of Hanggin Rear Banner of Inner Mongolia, Shaanba 015400, China
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| Abstract: |
| 【Background】Inferior irrigation and drainage management has resulted in soil salinization undermining agricultural production and water resources use efficiency in Hetao Irrigation District. Combing soil amendment and brackish groundwater irrigation could control soil salinity and has been widely studied. However, most existing research has focused on its impact on total soil salt and crop yield, while the associated change in ion composition has been overlooked.【Objective】The purpose of this paper is to study the influence of drip irrigation with brackish groundwater, along with different soil amendments, on salt dynamics and its ion composition in soil.【Method】The experiment was conducted in a moderate-heavy saline field in Hetao Irrigation District with sunflower as the model plant. It consisted of four treatments: ①Conventional flooding irrigation without soil amendment. ②Brackish water drip irrigation without soil amendment. ③Brackish water drip irrigation with soil amended by biochar. ④Brackish water drip irrigation with soil amended by gypsum. In each treatment, we measured salt content and its ion composition.【Result】The average soil desalination under brackish water drip irrigation was 13.46%, up 7.14% against the conventional irrigation. Drip irrigation did not lead to a noticeable salt accumulation, but compared with conventional irritation, it increased Na+ and Cl- content by 91.13% and 47.21% respectively, giving rise to sodication and salt accumulation in the 20~40 cm soil. Brackish water drip irrigation coupled with soil amendment by biochar or gypsum enhanced soil desalination and reduced soil sodication, especially the gypsum amendment which increased soil desalination by 46.30%. Compared with other treatments, brackish water drip irrigation coupled with biochar amendment increased salt content and proportion of K+, Mg2+ and SO42- in the topsoil during the growth season of the sunflower. On the contrary, brackish water drip irrigation with gypsum amendment reduced the proportion of Na+, Cl- and Mg2+ at the expense of Ca2+ and SO42- in the topsoil.【Conclusion】Brackish water irrigation coupled with soil amendment not only affected soil salinity but also alerted its ion composition. Combining brackish water drip irrigation with soil amendment with biochar and gypsum improved soil desalination and ameliorate sodium accumulation – a typical phenomenon accompanied with brackish water irrigation. Our results have important implications for improving saline-alkali soil management and water use efficiency in irrigated cropping systems in arid areas like Hetao Irrigation District. |
| Key words: brackish water drip irrigation; Hetao Irrigation District; soil salinity; ionic composition; biochar; gypsum |
