微咸水膜孔灌田间试验土壤水盐运移规律研究

发布时间：2018-06-17 01:18

本文选题：微咸水 + 膜孔灌　；参考：《河北工程大学》2017年硕士论文

【摘要】：利用微咸水与膜孔灌相结合的方式进行农田灌溉,能够充分发挥二者的优势,在一定程度上起到节水的效果。因此研究大田试验条件下微咸水膜孔灌土壤水盐运移规律是很有必要的。本文在查阅和分析国内外微咸水和膜孔灌理论与技术等相关文献资料的基础上,采用室外试验和理论分析相结合的技术路线,主要研究了微咸水膜孔灌田间试验条件下土壤水盐运移规律及再分布过程中土壤水盐的运移分布规律,主要研究成果如下:1.研究了灌水技术要素对微咸水膜孔灌田间试验土壤水盐运移规律的影响,其中灌水技术要素包括灌水量和膜孔直径,研究结果表明灌水技术要素对土壤水盐运移规律有较大影响。灌水量增大,土壤垂直湿润锋运移距离增大,湿润体内相同位置处土壤含水率增大,湿润体内表层土壤电导率值逐渐减小,深层土壤电导率值逐渐增加。膜孔直径增大,湿润体内表层土壤含水率增大,深层土壤含水率逐渐降低;膜孔直径增大,膜孔附近土壤电导率逐渐减小,深层土壤电导率逐渐增大。再分布过程并不影响灌水技术要素对土壤水盐运移影响。2.研究了微咸水水质对微咸水膜孔灌田间试验土壤水盐运移规律的影响,微咸水水质包含矿化度和钠吸附比两个因素,研究结果表明微咸水水质对土壤水盐运移规律有较大影响。灌溉水矿化度为3g/L,土壤的导水能力最大,矿化度增加,土壤的导水能力逐渐降低;灌溉水矿化度小于3g/L,土壤剖面存在脱盐区,灌溉水矿化度高于3g/L,土壤剖面全部积盐。钠吸附比增加,垂直湿润锋运移距离逐渐减小,湿润体内相同位置处土壤含水率逐渐增大。钠吸附比增加,对土壤相同位置土壤电导率值、土壤脱盐区、积盐区无较大影响。再分布过程并不影响微咸水水质对土壤水盐运移影响。3.研究了分次灌溉对微咸水膜孔灌土壤水盐运移规律的影响,分次灌溉包含灌溉次序和淡水续灌时间两个因素,研究结果表明分次灌溉对土壤水盐运移规律有较大影响。第一次灌溉水水质对土壤湿润锋运移距离、土壤含水率起主导作用,首次灌水为咸水的土壤湿润锋运移距离高于土壤首次灌水为淡水的处理,灌水次序咸-淡,中层土壤积盐效果明显;灌水次序为淡-咸,土壤表层和底层积盐。续灌时间由0h延长到12h,湿润体内相同位置处土壤含水率逐渐增大;表层土壤电导率逐渐减小,深层土壤电导率逐渐增大;续灌时间由12h延长到72h,土壤含水率与电导率分布规律与之相反。再分布过程并不影响分次灌溉对土壤水盐运移影响。综上所述,本文揭示了微咸水膜孔灌田间试验条件下,灌水量、膜孔直径、矿化度、钠吸附比、灌溉次序和淡水续灌时间对土壤水盐运移规律的影响,以上研究成果可以研究微咸水膜孔灌技术提供理论指导。
[Abstract]:Irrigation with the combination of brackish water and membrane pore irrigation can give full play to the advantages of the two and save water to a certain extent. Therefore, it is necessary to study the law of water and salt movement of soil water and salt irrigation under the condition of field test. On the basis of related literature and other related literature, the rule of soil water salt migration and the distribution of soil water and salt in the process of redistribution under the condition of field experiment of micro brackish water film hole irrigation were mainly studied with the combination of outdoor test and theoretical analysis. The main research results were as follows: 1. research on the irrigation technology elements to the brackish water film The effects of soil water and salt migration on soil irrigation field test, in which irrigation technology elements include the amount of irrigation and the diameter of the membrane pore, the results of the study show that the irrigation technology elements have a great influence on the soil water and salt migration law. The irrigation amount increases, the migration distance of the soil vertical wetting front increases, the soil moisture content increases at the same location in the wet body, and the moisture content increases. The electrical conductivity of the surface soil gradually decreased, the conductivity of deep soil increased gradually. The diameter of the membrane pore increased, the moisture content of the surface soil increased, the water content in the deep soil decreased gradually, the diameter of the membrane hole increased, the conductivity of soil near the membrane hole gradually decreased, and the conductivity of deep soil soil increased gradually. The redistribution process did not affect irrigation. The influence of technical factors on soil water and salt migration.2. studies the effect of brackish water quality on soil water and salt migration in the field experiment of micro brackish water film hole irrigation. The water quality of brackish water contains two factors: salinity and sodium adsorption ratio. The results show that the water quality of brackish water has a great influence on the movement of soil water and salt. The salinity of irrigation water is 3g/L, soil The water conductivity of the soil is the largest, the salinity is increased, the water conductivity of the soil decreases gradually, the salinity of the irrigation water is less than 3g/L, the soil profile is desalted, the salinity of the irrigation water is higher than that of the 3g/L, the soil profile is all salt, the sodium adsorption ratio increases, the migration distance of the vertical wetting front gradually decreases, and the soil moisture content increases gradually at the same position in the humid body. The increase of sodium adsorption ratio has no significant influence on soil conductivity, soil desalination and salt accumulation in the same soil position. Redistribution process does not affect the effect of salt water quality on soil water and salt migration..3. studies the effect of sub irrigation on the movement of water and salt in saline water membrane pore irrigation, and sub irrigation includes irrigation sequence and fresh water irrigation time. The results of the two factors show that sub irrigation has a great influence on soil water and salt migration. The first irrigation water quality plays a leading role in soil wetting front migration distance and soil moisture content. The migration distance of soil wetting front for the first irrigation is higher than the first irrigation of soil for fresh water, and the order of irrigation is salty and middle soil. The effect of salt accumulation is obvious; the order of irrigation is light salt, soil surface and bottom salt. The time of continuous irrigation is extended from 0h to 12h, the soil moisture content of the soil at the same position in the humid body gradually increases; the conductivity of the soil layer gradually decreases, the conductivity of the deep soil gradually increases; the continuous irrigation time extends from 12h to 72h, and the distribution law of soil water content and electrical conductivity On the contrary, the redistribution process does not affect the effect of sub irrigation on soil water and salt migration. In summary, this paper reveals the effects of irrigation, pore diameter, salinity, sodium adsorption ratio, irrigation order and fresh water on soil water and salt migration under the condition of field irrigation with brackish water membrane irrigation. The above research results can be used to study brackish water. The membrane hole irrigation technique provides theoretical guidance.
【学位授予单位】：河北工程大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S152.7

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