微润灌溉压力及埋深对土壤水分运移及青椒生长的影响
发布时间：2019-05-15 17:51
【摘要】：微润灌溉是一种新型的地下灌溉,它是将半透膜技术引进灌溉领域,以半透膜内外水势差为驱动力,以缓慢湿润土壤的方式,在作物根系形成土壤湿润体,达到灌溉目的。微润灌溉的地埋式灌溉方式避免或大幅度降低了农田水分的径流损失、蒸发损失和渗漏损失,减少了水分不必要的浪费,在运行过程中大大降低了运行成本。本文采用室内模拟试验和温室种植试验相结合的方法,研究了压力水头及管带埋深对灌溉土壤水分运移和青椒生长的影响;采用空气出流试验对田间使用一年的微润管的堵塞情况进行了研究。得出以下主要结论:(1)微润灌溉在粘壤土中的湿润体形状近似圆形;湿润体均呈现为微润管上部较小,下部较大的形状;在本试验条件下,微润灌溉土壤湿润体横截面面积与入渗时间的关系可以用指数函数进行拟合,拟合效果良好;压力水头越大,微润灌溉湿润体横截面积越大,且湿润体内的平均含水率越高;管带埋深的增加对微润灌溉湿润体的形状大小影响不显著;湿润体随微润管埋深的增加向下移动。(2)微润灌溉湿润锋在水平、垂直向上、垂直向下三个方向的运移距离随入渗时间的变化均符合幂函数关系。压力水头越大湿润体在三个方向上的运移距离越大。管带埋深较浅时,微润灌溉湿润体向上运移至地表,不利于较小水分蒸发损失;管带埋深为20cm时湿润体垂直向下运移距离没有显著变化。微润灌溉条件下入渗率随时间变化由入渗开始时段急速下降,随着入渗时间的延长,曲线逐渐趋于平缓。压力水头越大,累积入渗量越大,入渗率越大。随着管带埋深增加,累积入渗量有减小趋势。(3)微润灌溉湿润体内土壤水分含量随着距微润管距离的增加而减小,呈中间高边缘低的分布。在湿润体内部微润管附近含水量最高,含水量接近于田间持水量,湿润体内不存在饱和含水率区;距微润管相同距离时,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。压力水头越高湿润体内平均含水率越高;管带埋深对微润灌溉湿润体内平均含水率影响不显著。(4)微润灌溉压力水头与湿润体范围及湿润体内平均含水量呈正比关系。压力水头对青椒株高、茎粗增长的影响曲线符合Logistic模型;微润灌压力水头对青椒生育前期作物株高生长速率影响更为显著;微润灌溉条件下,青椒的生长发育适宜工作压力水头为150cm,压力水头为100cm时,青椒的灌溉水利用率最高。(5)管带埋深对微润灌溉湿润体含水量的影响不显著,土壤湿润体随着管带埋深的增加而向下移动;管带埋深对青椒株高、茎粗增长随时间的变化符合Logistic模型;微润灌溉条件下,青椒生长发育适宜的管带埋深为20cm,在此埋深处理下,青椒株高、茎粗、产量均为最大,青椒灌溉水生产率最高。(6)压力水头越大,微润管在空气中的出流量越大;微润管在空气中的出流量与供水时间呈正线性关系;本实验条件下,使用一年的微润管出现堵塞现象,空气中出流量仅为新管的15.9%;微润管内可见杂质对微润管的堵塞影响不大;经高压充水的旧微润管在空气中的出流量有明显提高。高压充水时间为4小时较为适宜,较未处理的旧微润管累积出流量提升了295%,达新微润管空气出流量的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%.
【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】：S152.7;S641.3
本文编号：2477682
[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%.
【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】：S152.7;S641.3
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