微润灌溉下不同质地土壤水分运移及设施蔬菜生长动态研究

发布时间：2018-08-31 09:28

【摘要】：微润灌溉作为一种新型的节水灌溉技术,与传统的灌溉技术相比,能够有效地改善土壤环境、减少土壤蒸发、提高水分利用效率。与滴灌、微喷灌及喷灌等节水灌溉技术相比,微润灌溉可调节水头,控制供水压力,从而可以满足作物在不同生长阶段土壤水分需求,具有更节水、更节能、更增产等优点。本论文开展了室内模拟试验和3种设施蔬菜种植试验,探究不同质地的土壤在不同的压力水头下,微润管出流、湿润锋运移与土壤水分分布规律情况,以及微润灌溉技术在节水效果与经济效益方面是否优于普通灌溉,从而可以为微润灌溉技术的应用与推广提供相应参考依据。本研究主要得到以下结论:1、在室内模拟试验中,不同土质下,供水压力对微润管在土壤中累计入渗量和入渗率的影响较大。湿润锋在各个方向上的运移距离随试验时间不断地向离微润管更远处推移,呈现出先快后逐渐变慢的趋势,运移速率逐渐减小。在水平向左、向右两个方向上的湿润锋距离相近。幂函数可以高度拟合湿润锋运移距离与试验时间之间的关系。分析湿润体某一剖面,黏壤土土样含水量以微润管处为中心向周围扩散,然后慢慢降低。2、在黏壤土土样和混合土样试验中,湿润锋在垂直向下方向上运移距离大于其他三个方向上的运移距离。从湿润体横断面来分析,湿润锋为近似规则的圆形,湿润体近似为圆柱体。在砂土试验中,湿润锋水平两个方向上的运移距离均大于垂直方向上的运移距离,且垂直向下的运移距离大于垂直向上。湿润锋近似为长轴远大于短轴的椭圆形,湿润体近似为椭圆柱体。在黏壤土土样和混合土样试验中,离微润管相同距离位置上,供水压力对土壤水分含量影响较大;在砂土试验中,供水压力对土壤水分含量的影响很小。在黏壤土土样和混合土样试验中,沿微润管埋设方向上,供水压力对湿润体水分分布有影响,土壤含水率随压力水头的增大而增大;而在砂土试验中,供水压力对砂土湿润体水分含量的影响较小。3、在设施蔬菜种植试验中,蔬菜日均灌水量变呈现先增大后减小趋势。微润灌溉处理下各种植箱土壤水分随着四季小葱生育期的进行,大体呈现先增大后趋于平稳状态。蔬菜株高随生育期的进行变化规律一致,幼苗期长势迅猛,之后株高增长变化逐渐缓慢,株高曲线为“S”型。压力水头为2.0m,微润管埋深为4cm处理最有利于四季小葱生长,产量最大,灌溉水分生产率最大;压力水头为2.0m,微润管埋深为5cm的处理最有利于紫油麦菜生长,产量最大,灌溉水分生产率最大;压力水头为2.0m,微润管埋设深度为8cm的处理最有利于白菜生长,产量最大,灌溉水分生产率最大。4、除在紫油麦菜试验中,微润管埋设深度为8cm,供水压力为2.0m的处理外,本设施蔬菜试验中,微润灌溉技术处理下蔬菜的灌水量均小于普通浇灌处理下的灌水量。且微润灌溉条件下,各处理的蔬菜产量均大于普通浇灌的蔬菜产量。说明与普通浇灌相比,不管是连续式还是间歇式,微润灌溉技术能得到节水增产的效果,同时可以提高灌溉水分生产率。
[Abstract]:As a new type of water-saving irrigation technology, micro-wetting irrigation can effectively improve soil environment, reduce soil evaporation and improve water use efficiency compared with traditional irrigation technology. Compared with drip irrigation, micro-sprinkler irrigation and sprinkler irrigation, micro-wetting irrigation can adjust water head and control water supply pressure to meet different crops. In this paper, indoor simulation experiments and three kinds of greenhouse vegetable planting experiments were carried out to explore the soil texture under different pressure water head, micro-wetting pipe outflow, wetting front migration and soil moisture distribution, and micro-wetting irrigation technology in water saving. The main conclusions of this study are as follows: 1. In the laboratory simulation test, the influence of water supply pressure on the cumulative infiltration and infiltration rate of micro-wetting pipe in soil is greater than that of ordinary irrigation. With the test time, the migration distance in the two directions is faster and then slower, and the migration rate decreases gradually. In one section of the wetting body, the moisture content of clay loam soil sample diffuses around the center of the micro-wetting pipe, and then decreases slowly. 2. In clay loam soil sample and mixed soil sample test, the moving distance of the wetting front in the vertical downward direction is larger than that in the other three directions. In sand tests, the horizontal and vertical migration distances of the wetting front are greater than those of the vertical direction, and the vertical downward migration distances are greater than those of the vertical direction. At the same distance from the micro-wetting pipe, the water supply pressure has a great influence on the soil moisture content; in the sand test, the water supply pressure has a little influence on the soil moisture content. In the sand experiment, the influence of water supply pressure on the moisture content of sandy soil is small. 3. In the greenhouse vegetable planting experiment, the daily average irrigation amount of vegetables increases first and then decreases. The vegetable plant height changed with the growth period, the seedling growth was rapid, then the plant height increased slowly, the plant height curve was "S" type. The treatment with 5 cm depth of embedding pipe was the most favorable for the growth of purple rape, with the highest yield and irrigation water productivity; the treatment with 2.0 m pressure water head and 8 cm depth of embedding pipe was the most favorable for the growth of Chinese cabbage, with the highest yield and the highest irrigation water productivity. 4. Except for the experiment with purple rape, the embedding depth of micro-embedding pipe was 8 cm and the water supply pressure was 2.0 M. In addition, in the vegetable experiment of this facility, the irrigation amount of vegetable under micro-wetting irrigation was less than that under ordinary irrigation, and the yield of vegetable under micro-wetting irrigation was higher than that under ordinary irrigation. The effect of saving water and increasing production can also increase the productivity of irrigation water.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S626;S275

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