Effects of initial water content and irrigation frequency on soil-water dynamics under subsurface drip irrigation

A study was performed on the effects of irrigation parameters on soil-water dynamics under subsurface drip irrigation (SDI), which has theoretical and practical values in guiding the design and operation of irrigation system. In this study, soil wetting patterns were investigated in laboratory experiments which were operated at three different initial water content in soil (0.108, 0.115 and 0.156 cm 3 cm -3 ) and three different time intervals (6, 12 and 24 h). The results showed that for a given water application, (1) the size of wetted zone increases with the increase of initial water content, (2) more irrigation frequency would lead to larger water distribution area and higher initial water content in soil near the emitter, (3) for a given emitter discharge rate, water contents around the emitter at continuous irrigation is greater than that at interval time of 6, 12 and 24 h.