【摘要】：微潤灌溉是一種新型的地下灌溉,它是將半透膜技術(shù)引進灌溉領(lǐng)域,以半透膜內(nèi)外水勢差為驅(qū)動力,以緩慢濕潤土壤的方式,在作物根系形成土壤濕潤體,達到灌溉目的。微潤灌溉的地埋式灌溉方式避免或大幅度降低了農(nóng)田水分的徑流損失、蒸發(fā)損失和滲漏損失,減少了水分不必要的浪費,在運行過程中大大降低了運行成本。本文采用室內(nèi)模擬試驗和溫室種植試驗相結(jié)合的方法,研究了壓力水頭及管帶埋深對灌溉土壤水分運移和青椒生長的影響;采用空氣出流試驗對田間使用一年的微潤管的堵塞情況進行了研究。得出以下主要結(jié)論:(1)微潤灌溉在粘壤土中的濕潤體形狀近似圓形;濕潤體均呈現(xiàn)為微潤管上部較小,下部較大的形狀;在本試驗條件下,微潤灌溉土壤濕潤體橫截面面積與入滲時間的關(guān)系可以用指數(shù)函數(shù)進行擬合,擬合效果良好;壓力水頭越大,微潤灌溉濕潤體橫截面積越大,且濕潤體內(nèi)的平均含水率越高;管帶埋深的增加對微潤灌溉濕潤體的形狀大小影響不顯著;濕潤體隨微潤管埋深的增加向下移動。(2)微潤灌溉濕潤鋒在水平、垂直向上、垂直向下三個方向的運移距離隨入滲時間的變化均符合冪函數(shù)關(guān)系。壓力水頭越大濕潤體在三個方向上的運移距離越大。管帶埋深較淺時,微潤灌溉濕潤體向上運移至地表,不利于較小水分蒸發(fā)損失;管帶埋深為20cm時濕潤體垂直向下運移距離沒有顯著變化。微潤灌溉條件下入滲率隨時間變化由入滲開始時段急速下降,隨著入滲時間的延長,曲線逐漸趨于平緩。壓力水頭越大,累積入滲量越大,入滲率越大。隨著管帶埋深增加,累積入滲量有減小趨勢。(3)微潤灌溉濕潤體內(nèi)土壤水分含量隨著距微潤管距離的增加而減小,呈中間高邊緣低的分布。在濕潤體內(nèi)部微潤管附近含水量最高,含水量接近于田間持水量,濕潤體內(nèi)不存在飽和含水率區(qū);距微潤管相同距離時,垂直向上方向的土壤含水率小于垂直向下方向的土壤含水率。壓力水頭越高濕潤體內(nèi)平均含水率越高;管帶埋深對微潤灌溉濕潤體內(nèi)平均含水率影響不顯著。(4)微潤灌溉壓力水頭與濕潤體范圍及濕潤體內(nèi)平均含水量呈正比關(guān)系。壓力水頭對青椒株高、莖粗增長的影響曲線符合Logistic模型;微潤灌壓力水頭對青椒生育前期作物株高生長速率影響更為顯著;微潤灌溉條件下,青椒的生長發(fā)育適宜工作壓力水頭為150cm,壓力水頭為100cm時,青椒的灌溉水利用率最高。(5)管帶埋深對微潤灌溉濕潤體含水量的影響不顯著,土壤濕潤體隨著管帶埋深的增加而向下移動;管帶埋深對青椒株高、莖粗增長隨時間的變化符合Logistic模型;微潤灌溉條件下,青椒生長發(fā)育適宜的管帶埋深為20cm,在此埋深處理下,青椒株高、莖粗、產(chǎn)量均為最大,青椒灌溉水生產(chǎn)率最高。(6)壓力水頭越大,微潤管在空氣中的出流量越大;微潤管在空氣中的出流量與供水時間呈正線性關(guān)系;本實驗條件下,使用一年的微潤管出現(xiàn)堵塞現(xiàn)象,空氣中出流量僅為新管的15.9%;微潤管內(nèi)可見雜質(zhì)對微潤管的堵塞影響不大;經(jīng)高壓充水的舊微潤管在空氣中的出流量有明顯提高。高壓充水時間為4小時較為適宜,較未處理的舊微潤管累積出流量提升了295%,達新微潤管空氣出流量的62.8%。
[Abstract]:The micro-wetting irrigation is a new type of underground irrigation, which introduces the semi-permeable membrane technology into the field of irrigation, and uses the water potential difference between the inside and outside of the semi-permeable membrane as the driving force to form the soil wetting body in the root system of the crops so as to achieve the purpose of irrigation. The submerged irrigation method of the micro-run irrigation avoids or greatly reduces the runoff loss, the evaporation loss and the leakage loss of the water in the farmland, reduces the unnecessary waste of the water, and greatly reduces the running cost in the running process. In this paper, the effects of the pressure head and the buried depth of the pipe on the soil moisture transport and the growth of the green pepper are studied by the combination of the indoor simulation test and the greenhouse planting test. The air outflow test is used to study the plugging of the micro-wetting pipe in the field. The following main conclusions are drawn: (1) the shape of the wet body of the micro-wetting irrigation in the clay loam is approximately circular; the wetting body is shown as a small and a larger shape in the upper part of the micro-wetting pipe; under the test condition, The relationship between the cross-sectional area of the wet body and the infiltration time of the micro-run irrigation soil can be fitted with an exponential function, and the fitting effect is good; the larger the pressure head, the larger the cross-sectional area of the micro-run irrigation wet body, and the higher the average water content in the wet body; The effect of the increase of the buried depth of the tube on the shape and the size of the micro-wetting irrigation wet body is not significant; the wetting body moves downwards with the increase of the depth of the micro-wetting tube. (2) The moving distance of the wet front of the micro-run irrigation in the horizontal, vertical and vertical direction is in accordance with the power function relation with the change of the infiltration time. The greater the pressure head, the greater the moving distance in the three directions. When the buried depth of the pipe belt is shallow, the micro-wetting irrigation wet body moves up to the surface, which is not conducive to the evaporation loss of small water, and the vertical downward movement distance of the wet body does not change significantly when the buried depth of the pipe belt is 20 cm. Under the condition of micro-run irrigation, the infiltration rate decreased rapidly from the start of infiltration, and the curve gradually decreased with the time of infiltration. The greater the pressure head, the greater the amount of accumulated infiltration and the greater the infiltration rate. As the buried depth of the pipe belt is increased, the cumulative infiltration amount has a tendency to decrease. (3) The content of the soil moisture in the wet-running wet-water is reduced with the increase of the distance from the micro-wetting tube, and the water content in the wet-running wet-wet body is lower than that of the middle high-edge. The water content in the vicinity of the micro-wetting pipe in the wet body is the highest, the water content is close to the field water holding capacity, and the saturated water content area is not present in the wet body; and when the water content is the same distance from the micro-wetting pipe, the water content of the soil in the vertical upward direction is less than the water content of the soil in the vertical downward direction. The higher the pressure head, the higher the average water content in the wet body, and the effect of the buried depth of the pipe on the average water content in the wet-wet irrigation wet body is not significant. (4) The water head of the micro-run irrigation is directly proportional to the range of the wet body and the average water content in the wet body. The effect of the pressure head on the high and coarse growth of the green pepper is in line with the Logistic model, and the effect of the micro-wetting irrigation pressure head on the high growth rate of the early-stage crops in the green pepper is more obvious; under the condition of micro-moist irrigation, the growth and development of the green pepper is suitable for the working pressure head of 150 cm and the pressure head is 100 cm, The irrigation water utilization rate of green pepper is the highest. (5) The depth of the buried depth of the pipe is not obvious to the water content of the micro-wetting irrigation wet body, and the soil wetting body moves downwards along with the increase of the depth of the buried depth of the pipe belt, the depth of the pipe belt is higher than that of the green pepper plant, the change of the coarse growth of the stem and the time is in accordance with the Logistic model, and under the condition of the micro-wetting irrigation, The best growth and development of green pepper is 20 cm, and under the deep treatment, the green pepper plant is high, the stem is thick, the yield is the largest, and the water production rate of the green pepper is the highest. (6) The larger the pressure head, the greater the outlet flow of the micro-wetting tube in the air; the discharge flow of the micro-wetting tube in the air is in a positive linear relation with the water supply time; under the experimental condition, the micro-wetting tube of one year is used to cause the blockage phenomenon, and the flow rate in the air is only 15.9% of the new tube; The visible impurities in the micro-run tube have little influence on the blockage of the micro-wetting tube, and the flow rate of the old micro-wetting tube with high-pressure water filling in the air is obviously improved. The high-pressure water-filling time is more suitable for 4 hours, the accumulated flow rate of the less-treated old micro-wetting pipe is increased by 295%, and the air outlet flow of the new micro-wetting pipe is 62.8%.
【學位授予單位】：太原理工大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：S152.7;S641.3

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