Laboratory Experimental Study On Soil-water Movement Of Surface Drip Irrigation And Subsurface Drip Irrigation

The paper analysied and summaried home and abroad soil-water migration about the surface and subsurface drip irrigation research, using laboratory experiments, studied the the basic law of surface and subsurface point source drip irrigation of soil-water movement.The paper do the reserch of Point sources of surface drip irrigation in the same soil texture, bulk density of different soil, different irrigation flow rate and different initial soil water content of different drip irrigation under the humid time of peak migration law, and also research the end of surface drip irrigation and 24 hours after the end of the irrigation about soil-water changes. The results showed that during the drip irrigation, wetting the soil was similar to elliptical (in part) or parabolic (part); for different soil bulk density, bulk density, the greater the wetting speed of the smaller vertical migration, but the level of speed is greater; for different flow drip irrigation, drip irrigation, the greater the flow, wetting the horizontal and vertical migration of the greater speed; for different initial soil water content, initial soil-water content the greater the wetting The horizontal and vertical movement the greater the speed. The end of the drip irrigation in the humid interior of the sampling points from the emitter closer, the greater the soil-water content, the farther from the emitter, soil-water also smaller, wetting the edge of the lowest soil-water. At the end of the drip irrigation in the humid interior of the sampling points from the emitter closer, the greater the soil-water content, the farther from the emitter, soil-water also smaller, wetting the edge of the lowest soil-water. After the end of the drip irrigation, soil-water water in the body in gravity and other effects will continue migration.24 hours after the end of the drip irrigation, soil-water at the end of the body volume than drip irrigation significantly increased; moisture content in the vertical direction, the variation is:With the increase of the vertical depth of moisture content gradually become larger, the soil-water content of soil bottom of the tank rate was the highest; in the horizontal direction, with the right soil-water content decreased with increasing distance, wetting the edge of the lowest soil-water.The paper reserched of Point sources of subsurface drip irrigation in the same soil texture, different irrigation flow rate and different initial soil water content of different drip irrigation under the humid time of peak migration law, and also research the end of surface drip irrigation and 24 hours after the end of the irrigation about soil-water changes. The results show that the surface drip irrigation and subsurface drip irrigation of the Soil-water movement were Similar, but there were many different places. Wetting the soil subsurface drip irrigation early in the approximate oval, wetting, after reaching the ground, as time goes on, the shape of the wetting surface point source with the shape similar to the drip. For different initial soil water content, the greater the initial soil water content, soil-water peaks greater horizontal and vertical velocity. The end of the drip irrigation in the humid interior of, emitter soil-water at the maximum, with increasing distance from the emitter, soil-water decreases, wetting the soil-water at the edge of the minimum; emitter for the same distance sampling points straight up straight down the moisture content than the moisture content of the small sampling points.24 hours after the end of the drip irrigation, soil-water than the volume also increased significantly at the end of drip irrigation; in the distribution of moisture, in the vertical direction, with the increase of the vertical depth of soil-water increases, soil box the maximum moisture content of the bottom; in the horizontal direction, soil-water increased with distance to the right decreases, wetting the edge of the lowest soil-water.The results of this paper will helped us to understand Soil-water movement law about the surface point source drip irrigation and subsurface drip irrigation deeply, and provided the necessary depth of test data of drip irrigation to promote water-saving projects in our province, and also has some significance to building efficient and saving water for agriculture in our province.