| 摘要: |
| 【目的】研究滨海缺水地区在盐碱地上利用微咸水灌溉进行绿色农业生产的可行性和安全性。【方法】以番茄为研究对象，采用“滴灌水盐调控+垄作”模式，以深层地下淡水（0.7 dS/m）为对照，田间布置了4种不同电导率（3.2、4.7、6.2、7.8 dS/m）的微咸水，研究微咸水灌溉对土壤剖面盐分分布和番茄生长、产量及品质性状等代表性指标的影响。【结果】利用3.2~7.8 dS/m的微咸水灌溉番茄，试验结束时整个土体的盐分并没有显著增加，在整个土体中进行了重新分布，在距离滴头0~10 cm远的0~60 cm深度范围存在一个明显的盐分淋洗区，盐分主要是被淋洗到70 cm深度以下和距离滴头20~40 cm远的垄坡和垄沟的表层（0~20 cm）。随着灌溉水电导率（ECi）的增加，LAI、地上部和地下部生物量先增加后减少，株高和茎粗有逐渐降低的趋势，且当ECi＞4.7 dS/m时，各生长指标较淡水处理显著降低。不同处理番茄叶片中叶绿素总量、类胡萝卜素、丙二醛和脯氨酸量差异不显著，但微咸水灌溉显著降低了番茄叶片中可溶性糖量。随着ECi的增加，番茄果实中可溶性固形物、还原糖、有机酸量逐渐增多，而果实糖酸比逐渐降低；番茄的产量随着ECi的增加而降低，通过公式拟合发现，当ECi＞1.4 dS/m时，ECi每增加1 dS/m，番茄的产量降低9.7%。【结论】总体而言，在淡水紧缺的滨海半湿润地区，盐碱地上种植番茄可以利用电导率≤4.7 dS/m的微咸水进行灌溉，尽管相对于淡水灌溉，番茄的产量有所降低，但可以节省300 mm以上的淡水量，番茄的品质提高，并且整个土壤剖面盐分可以维持平衡。 |
| 关键词: 微咸水；滴灌；生长指标；生理指标；果实品质；番茄 |
| DOI：10.13522/j.cnki.ggps.2019408 |
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| Effects of Water-salt Regulation on Tomato Growth and Quality under Drip Irrigation with Brackish Water in Coastal Saline-alkali Soil |
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LI Dan, WAN Shuqin, KANG Yuehu, LI Xiaobin
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1.Key Laboratory of Water Cycle and Related Land Surface Processes,Institute of Geographical Sciences and Natural Resources Research, CAS, Beijing 100101, China;2. College of Resources and Environment, University of Chinese Academy of Sciences, UCAS, Beijing 100049, China
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| Abstract: |
| 【Background】 With the growing demand for agricultural products and the increasing shortage of agricultural freshwater resources in coastal areas, the development of drip irrigation with brackish water can play a crucial role in relieving the pressure of agricultural water supply. Because most of the soil in coastal areas have a heavy texture and high salinity, and therefore crop growth is challenging. Previous studies have shown that brackish water irrigation can significantly change soil moisture, salinity distribution, and crop quality. However, few studies have conducted systematic experiments to analyze the effects of drip irrigation with brackish water on the crop qualities under water-salt regulation methods. Thus, we introduced drip irrigation and a water-salt regulation method into tomato planting to bridge this gap. This study has potential contributions to urban eco-environment construction, green agricultural development, and exploitation of brackish water, especially in coastal areas with a large amount of brackish water available in shallow groundwater. 【Objective】 This study aims to investigate the feasibility and safety of green agricultural production under drip irrigation with brackish water in coastal saline-alkali soil. 【Method】 To research the effect of brackish water irrigation on tomato growth, yield, quality characteristics, and salinity distribution of the soil profile, we used the conductivity of deep underground water( 0.7 dS/m) as a control check and conducted four tomato treatments with brackish water of different conductivity (3.2 dS/m, 4.7 dS/m, 6.2 dS/m, 7.8 dS/m). The tomatoes were subjected to saline drip irrigation and ridge cultivation using a water-salt regulation method. 【Result】The salinity of the entire soil did not increase significantly, whereas the salinity of the soil profile was redistributed when tomatoes were irrigated with brackish water of 3.2 to 7.8 dS/m. There was an apparent salt leaching zone in the area 10 cm wide and 0~60 cm deep from the dripper. The salinity was mainly washed down to a depth of 70 cm and the surface of ridges and ditches (0~20 cm) that were 20~40 cm away from the dripper. With the increase of irrigation water electrical conductivity (ECi), LAI, fresh weight, and dry weight increase and then decreased, while the plant height and stem thickness gradually decreased. Moreover, all indicators reduced significantly compared with fresh water treatment(0.7 dS/m) when the conductivity exceeded 4.7 dS/m. No significant difference in chlorophyll, malondialdehyde (MDA), carotenoid, and proline content under different treatments, while brackish water irrigation significantly reduced the content of soluble sugar in the leaves. With the increase of ECi, the contents of soluble solids, reducing sugar, and organic acid in tomato fruits gradually increased, whereas the sugar-acid ratio and yield gradually decreased. Besides, when ECi exceeded 1.4 dS/m, for every 1 dS/m increase of ECi, the yield decreased by approximately 9.7% employing formula fitting. 【Conclusion】 In summary, the brackish water irrigation with a conductivity of 4.7 dS/m or less can be used to irrigation in coastal saline-alkali soil where freshwater scarce. Although the yield was reduced, over 300 mm of the water can be saved compared to freshwater irrigation and the quality of tomatoes was also improved, and the salinity balance across the soil profile can be maintained. |
| Key words: brackish water; drip irrigation; growth indicator; physiological indicator; fruit quality; tomato |
