New-style Irrigation And Drainage Pipe Application Technology

In this paper, new-style irrigation and drainage pipe as the main object, its irrigation technical parameters in different application areas were explored by soil box discharge simulation irrigation test, field irrigation test, green roof irrigation test and horticulture frame irrigation test, with a view to provide references for new-style irrigation and drainage pipe in different areas of application; its drainage technical parameters and drainage and salt discharge effect were explored by the field simulation drainage and salt discharge test, in order to provide a theoretical basis for its application in subsurface drainage project. The main conclusions are as follows:(1) Seepage rate with the irrigation period was gradually reduced after the first stable trend when 0.5-0.6m head used in soil box simulation irrigation. Horizontal migration distance of 0-80 cm soil wetting front is about 70 cm. Accordingly pipe pitch only about 1.5 meters, smaller, not the economy, test with different water pressure needs to be continued to determine the appropriate pressure and appropriate irrigation pipe spacing. The horizontal distance from the infiltration pipe 0-20 cm area, all soil moisture content is greater than 18%; infiltration pipe horizontal distance from 25-30 cm area, soil moisture content is substantially reached 16.5%. The horizontal distance from the infiltration of pipe 30-35 cm area, soil moisture basically reached 15%. Soil moisture uniformity becomes 79.3% after the wait soil water redistribution, in line with the requirements of water-saving irrigation.(2) Water lateral migration distance of 0.5 m and 1.0 m head treatment are about 0.5 maters which lasted five hours after irrigation in field irrigation test. Water lateral migration distance of 1.0 m head treatment is about 1.0 meters and water lateral migration distance of 1.0 m head treatment is about 0.75 meters which lasted ten hours after irrigation. One day after irrigation, lateral migration distance did not change significantly. On the whole soil moisture of 1.0 m head treatment is greater than 1.0 m head treatment. Different irrigation duration, soil moisture vertical uniformity of 0.5 m and 1.0 m head treatment were greater than 90%, transverse uniformity were greater than 85%, they are in line with water-saving irrigation uniformity requirements, indicating little impact on irrigation and drainage pressure head pipe irrigation uniformity. Seepage rate with increasing distance from the inlet becomes smaller, with increasing irrigation head gradually increases. For 0.5 m headtreatments, seepage rate of 0-30 meters of pipe sections smaller differences, were significantly higher than 30-40 meters of pipe; for 1.0 m head handle, the smaller each pipe seepage rate differences. When the pipe is used for field irrigation, 1.0 m irrigation head is suitable, about 10 hours once irrigation time is appropriate, laying spacing 1.5-2.0 meters is appropriate, maximum buried pipe about 40 meters, according to the specific situation on the ground reasonable arrangements. Long-term field new-style irrigation and drainage pipe buried irrigation, failure to take any anti-clogging measures clogging situation is more serious. Laying dark pipe buried outsourcing filter can effectively prevent soil particles and other contaminants into the subsurface irrigation pipe with the water, in order to reduce pipe blockage.(3) When new-style irrigation and drainage pipe is used for green roof irrigation, 0.5-0.6 m irrigation head is suitable, laying spacing 3.0 meters is appropriate, practical applications, according to the roof slope, irrigated area and other reasonable choice. About 2 hours once irrigation time is appropriate, practical irrigation, according to factors vegetation type, base layer thickness and the local climatic conditions, the rational development of irrigation system.(4) When new-style irrigation and drainage pipe is used for horticulture frame irrigation, 5 hours continuous irrigation, gardening frame planting groove filling 130 cm thick honest dried matrix layer can be completely saturated. Matrix evaporation rate was positively correlated with low, almost no correlation matrix initial moisture content. 4-5 day interval irrigation cycle can be used as an initial reference. Developing practical irrigation cycle cannot wait for the matrix after drying, then irrigation should be further tested to find more suitable matrix lowest water content is the key. Step test results show that, in order to reduce evaporation, irrigation can begin after the fall dry skin matrix, irrigation time control at 1.5-2.0 hours to complete irrigation.(5) In field simulation drainage and discharge salt test, with the tube depth increases, the drainage rate and drainage period were gradually increased, and thus the total displacement increases. Total displacement and drainage lasted there is a good correlation can predict total displacement curve fitting. Draw a higher degree of curve fitting to note the range of Experimental conditions allow, try to collect more cumulative displacement measured values and Experimental design uniformity of data collection time pay attention to the node. Depth 1.0 m under conditions of maximum transverse drainage pipe and drainage sphere of influence among 13-15 meters, 10 meters range effect is more significant. Thus, depth 1.0 m under the conditions recommended laying pipe 20 m spacing is appropriate. Initialverification and drainage pipe row salt works well, salt drainage rate and drainage rate was significantly positively correlated with the rate of discharge of salt drainage rate increases. The presence of pipe drain phenomenon during the NO3-N and NH4-N loss, NO3-N loss rate and drain rate was a significant positive correlation, NH4-N loss rate and drain rate basically irrelevant.