新疆哈密深层坑渗灌葡萄根系分布特征及吸水模型研究

发布时间：2018-08-02 12:27

【摘要】：新疆地区是我国缺水最严重的地区之一,该地区基本不受夏季季风气候影响,“荒漠绿洲,灌溉农业”是其显著特点,属于无水利即无农业的地区。新疆地区的主要用水方面就是农业用水,约占总用水量的94%,在如此缺水的地区,如何改良节水的灌溉技术进而提高水分利用效率是该地区农业发展的重中之重。在诸多的节水灌溉技术均未能普遍运用在极端干旱区的情况下,深层坑渗灌是以蓄水坑灌、小管出流灌、渗灌为基础提出的一种新型灌水技术。本文结合大田试验以及室内机理试验对葡萄的根系分布特征以及根系吸水模型展开研究,为深层坑渗灌技术的推广提供理论依据。主要研究成果有:(1)全生育期内深层坑渗灌与传统沟灌灌溉条件下的葡萄根区土壤水分分布规律。结果表明深层坑渗灌条件下,在葡萄的果实膨大期和浆果成熟期含水量最高;传统沟灌条件下,各时期的含水率都处在非常高的水平上,在不需要过量水分的物候期依然投入了很多灌水,可以看出传统的灌溉方式对水资源的利用不合理造成了较高的浪费,除此之外,由垂向与径向方向上的含水率动态变化规律来看,含水率的分布与灌水器埋设位置具有较强的相关性。(2)深层坑渗灌灌溉与传统沟灌方式下的葡萄耗水规律。在深层坑渗灌的灌溉方式下,不同生育期中,表现为果实膨大期耗水量最大,作物耗水量随灌溉定额的变化而变化。而沟灌条件下棵间蒸发量每个时期都是深层坑渗灌的两倍,表明深层坑渗灌用于极端干旱且蒸发强度较高的吐哈地区可以有效解决土壤表层由于剧烈的蒸发强度而导致灌溉水浪费的问题。(3)分别用挖掘法与微根管法对成龄葡萄根系进行研究并得到葡萄根系的分布规律。微根管法与挖掘法相比,在垂直方向上,分布规律较为相似。在水平方向上,两种方法差别较大,由此可见葡萄根系在水平方向上的空间分布规律更为复杂。最后结合试验数据建立深层坑渗灌条件下葡萄的一维、二维、三维根系分布函数。(4)通过计算葡萄潜在根系吸水速率与土壤水分胁迫函数分别建立了基于挖掘法与微根管法的三维根系吸水模型。然后采用hydrus-3D模型对所建立的三维吸水模型进行求解,利用模拟期为15天内的根区土壤水分分布状态来验证模型的准确性,结果显示在
[Abstract]:Xinjiang is one of the regions with the most serious water shortage in China. It is basically independent of the summer monsoon climate. "Desert oasis, irrigated agriculture" is its remarkable feature and belongs to the region without water conservancy or agriculture. The main water use in Xinjiang is agricultural water, which accounts for 94% of the total water consumption. How to improve water-saving irrigation technology and improve water use efficiency is the most important part of agricultural development in this region. In the case that many water-saving irrigation techniques are not widely used in extreme arid areas, the deep pit seepage irrigation is a new irrigation technology based on water storage pit irrigation, small pipe drainage irrigation and seepage irrigation. In this paper, the characteristics of root system distribution and the model of root water absorption of grape were studied in combination with field test and mechanism test in laboratory, which provided the theoretical basis for the popularization of deep pit infiltration irrigation technology. The main results are as follows: (1) the distribution of soil moisture in the grape root region under the condition of deep pit infiltration irrigation and traditional furrow irrigation during the whole growth period. The results showed that under the condition of deep pit infiltration irrigation, the water content of grape was the highest at the stage of fruit expansion and berry ripening, and the moisture content of each stage was very high under the condition of traditional furrow irrigation. There is still a lot of irrigation in the phenological period where there is no need for excess water. It can be seen that the traditional irrigation methods have resulted in a high waste of water resources, in addition to the unreasonable use of water resources. According to the dynamic variation of water content in vertical and radial direction, the distribution of water content has a strong correlation with the location of emitter. (2) the water consumption of grape under deep pit infiltration irrigation and traditional furrow irrigation. Under the irrigation mode of deep pit infiltration irrigation, the water consumption in different growth periods was the largest in the period of fruit expansion, and the water consumption of crops changed with the change of irrigation quota. And under the condition of furrow irrigation, the evaporation rate between trees is twice as much as that of deep pit infiltration irrigation in every period. The results show that the deep pit infiltration irrigation can effectively solve the problem of irrigation water waste caused by the intense evaporation intensity of soil surface in Tuha area with extreme drought and high evaporation intensity. (3) the method of digging and micro-root canal are used to solve the problem of irrigation water wasting. Grape root system was studied and the distribution of grape root system was obtained. The distribution pattern of microroot canal method is similar to that of mining method in vertical direction. In horizontal direction, the difference between the two methods is great, so the spatial distribution law of grape root system in horizontal direction is more complex. Finally, based on the experimental data, one and two dimensions of grape under the condition of deep pit infiltration irrigation were established. Three-dimensional root distribution function. (4) by calculating the potential root water absorption rate and soil water stress function, a three-dimensional root water absorption model based on mining method and micro-root canal method was established. Then the hydrus-3D model is used to solve the three-dimensional water absorption model. The accuracy of the model is verified by using the soil moisture distribution in the root zone within 15 days.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S663.1;S275

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