红壤涌泉灌水分入渗特性研究

发布时间：2018-01-04 19:09

本文关键词：红壤涌泉灌水分入渗特性研究　出处：《南昌工程学院》2017年硕士论文　论文类型：学位论文

【摘要】：涌泉灌技术是针对中国滴灌系统使用过程中传统灌水器容易堵塞的弊端,以及农业生产管理水平低的状况而形成的一种适用于果树和植树造林的微灌技术。近年来的大部分涌泉灌溉研究大多针对山西、河北、新疆等干旱盆地的大田宽行作物的果园试验区进行研究,但针对江西等水资源相对充足地区进行试验极少。在历年来的涌泉灌系统设计中,出水口间距主要根据植物的种植间距来确定,本文主要考虑土壤容重、灌水流量和土壤初始重量含水率等因素,通过正交设计软件对试验进行简化,通过室内试验对红壤涌泉灌溉条件下的湿润体内入渗水分的运移规律进行研究,最后还通过正交设计软件和SPSS软件对三种不同的考察因素进行分析,得出每种考察因素对应的最优灌水技术参数。具体研究结果如下:(1)出水口下方的水平和垂直方向上的湿润体最大湿润半径均随入渗时间的推移呈增大的趋势,入渗初期水平和垂直方向上的湿润体湿润半径的增长速度远远大于入渗后期,且垂直湿润锋在相同时间段内的运移距离小于水平湿润锋,但随着入渗时间的推移垂直湿润锋逐渐和水平湿润锋逐渐接近;(2)随着入渗时间的延长,湿润体的形状亦发生着变化,由起初的横轴长纵轴短的1/4的横卧椭球体,逐渐变成接近于1/4全圆球体,椭球型的剖面形状可用长轴和短轴随时间变化的椭圆方程表示;红壤涌泉灌土壤内的入渗水分再分布过程主要发生在灌水结束后的24h内,再分布过程中,出水口下方的水平和垂直方向湿润锋的运移速度以及湿润锋的变化值均为垂直方向大于水平方向,湿润体的形状也由1/4全圆球体变为1/4垂直椭球体;(3)灌水刚结束时的湿润体内的土壤含水率在24.72%~34.15%范围之间,而入渗水分再分布24h后,湿润体土壤含水率降为16.81%~24.04%范围之内;距出水口同一距离下,土体含水率随着土体深度的增加而减小;同一土层深度下,土体含水率随着距出水口距离的增大而减小,但减小的幅度均较小;(4)通过正交设计软件和SPSS软件分析得到,最优灌水技术参数应设定为容重1.34g/cm3、灌水流量3.0L/H、初始重量含水率7.0%,在相同入渗时间内灌溉的水平根系范围越大,横向根系发达植物生长得越好;最优灌水技术参数应设定为容重1.20g/cm3、灌水流量3.0L/H、初始重量含水率7.0%,在相同入渗时间内灌溉的纵向根系深度越深,纵向根系发达植物生长得越好,但同时应酌情控制灌溉时间,以避免灌溉水的深层渗漏、混合水肥的流失浪费以及水体污染;最优灌水技术参数应设定为容重1.20g/cm3、灌水流量3.0L/H、初始重量含水率5.0%,在相同时间内土壤含水率越高,植物根系吸收水分越充分;(5)综合水平湿润锋运移距离、垂直湿润锋运移距离和再分布24h后土壤含水率三种因变量的优势考虑,将控制因素设定为容重1.20g/cm3、灌水流量3.0L/H、初始重量含水率7.0%,在相同入渗时间内在湿润体覆盖更多的植物根系的同时又能使植物根系充分吸收水分。
[Abstract]:Bubble irrigation technique is based on the disadvantages of the traditional emitter clogging of drip irrigation system using Chinese process, suitable for fruit trees and afforestation irrigation technology and management level of agricultural production is low and the formation of research in recent years. Most of the spring irrigation mostly in Shanxi, Hebei, on orchard test area wide field crops Xinjiang basin drought, but the test for Jiangxi and other relatively abundant water resource area rarely. In the years of bubble irrigation system design, the main outlet spacing according to the plant planting spacing is determined, this paper considers the factors of water flow and soil bulk density, initial soil weight moisture content, through the orthogonal test the software design is simplified, through indoor test research on soil springs under condition of irrigation infiltration of water into the moist body movement, and finally through the On three different factors were analyzed by orthogonal design and SPSS software, the optimal technique parameters for each factors. The main results are as follows: (1) the maximum wetting radius of wetting body under the water outlet of the horizontal and vertical directions with the infiltration time was increased, the the initial infiltration wetting radius of horizontal and vertical direction of the growth rate is far greater than infiltration stage, and the vertical wetting front movement in the same period of time is less than the distance between the horizontal wetting front, but with the passage of the vertical wetting front infiltration time and the horizontal wetting front gradually approaching; (2) with the infiltration time prolonged, moist body shape also changed, from the lying ellipsoid initial transverse longitudinal axis of short 1/4, gradually become closer to the 1/4 sphere, ellipsoid type profile available long axis and short axis at any time Said the elliptic equation changes between red soil; Bubble Irrigation in soil infiltration redistribution after irrigation mainly occurred in 24h, in the process of re distribution, migration velocity of outlet below the horizontal and vertical wetting front and the wetting front change values are greater than the vertical horizontal direction, the wetting the shape by 1/4 sphere to 1/4 vertical ellipsoid; (3) at the end of the irrigation wetting of the soil moisture content in the range of 24.72%~34.15%, and the infiltration water redistribution 24h after wetting the soil moisture content reduced to the range of 16.81%~24.04%; the outlet from the same distance, soil water content decreased with the increase of soil depth; the same depth, soil water content decreased with increasing distance from the outlet, but the rate of decrease was smaller; (4) obtained by orthogonal design software and SPSS software analysis, the most Optimal irrigation technical parameters should be set for the bulk density of 1.34g/cm3, water flow rate 3.0L/H, 7% of the initial moisture content, at the same time infiltration range of horizontal root irrigation is bigger, the lateral root developed better plant growth; optimal irrigation technical parameters should be set for the bulk density of 1.20g/cm3, water flow rate 3.0L/H, 7% of the initial moisture content, the more deep at the same time the longitudinal root depth of infiltration irrigation, vertical root developed plants grow better, but at the same time as appropriate controlling irrigation time, to avoid the deep seepage of irrigation water, mixed fertilizer loss waste and water pollution; optimal irrigation technical parameters should be set for the bulk density of 1.20g/cm3, water flow rate 3.0L/H, 5% of the initial weight of water rate, soil water content was higher at the same time, plant roots absorb water more fully; (5) the comprehensive level of wetting front distance, vertical wetting front distance and then 24h after the soil moisture content of three kinds of dependent variable advantages to consider, the control factors are set as bulk density 1.20g/cm3, water flow rate 3.0L/H, 7% of the initial moisture content, at the same time the intrinsic infiltration wetting cover the roots more at the same time can make the plant roots absorb water.

【学位授予单位】：南昌工程学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S152.7;S275

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