Experimental Research on Capillary Depth to Soil Water Transport under Line Source Permeation of SDI

Based on a primary experiment in the laboratory, the soil-water distribution of subsurface drip irrigation is observed and analyzed. The results show that the wetting front move speed and migration distance reduce in the vertical direction and horizontal direction along with the increment of the capillary depth under the same flow rate and water volume. Under the same capillary depth, the level of water content under the emitter soil is higher than in the other direction. The water content in the horizontal direction presents symmetry distribution. Under the same emitter distance, the moisture content is higher when capillary depth become greater. With the increment of the capillary depth, the moisture content decreases, increasing the ball saturated humid region, particularly in the vertical direction.