Experimental Study on Soil-water Movement under Subsurface Drip Irrigation

[Objective] The purpose was to study the movement law of soil-water under subsurface drip irrigation. [Method] The soil water content was determined by TDR. The movement dynamic of wetting front in the irrigation course of subsurface drip irrigation was observed continuously and the distribution status of soil water content when the irrigation ended and after 24 h were observed. [Result] As time extended, the development speed of wetting front reduced gradually. The overall distribution of isolines of water contents was approximate ellipse when the irrigation ended, which accorded with the common character of water distribution in loam soil. Due to evaporation factor, the soil water content was 9.2% in the part close to ground surface, smaller than the initial soil water content. After 24 h since stopping irrigation, besides that the water content in soil interior was distributed newly, the shape and scope of wetted soil body had bigger change and the water reached the underground depth of 70 cm, but the movement of wetted body in horizontal direction was not significant. [Conclusion] The infiltration characters of soil water under subsurface drip irrigation were learnt about preliminarily in the research.