| Wetted percentage is one of the most important parameters of drip irrigation system designing. According to layered bulk density soil in greenhouse of Jinzhong Area, experiments were conducted to test effects of wetted percentage on plant growth under drip irrigation on the base of investigation of water infiltration into layered soil. The results showed that: (1) Layered bulk density soil had great effects on water infiltration into soil. The distance and depth of wetted volume in original layered soil were lower than in homogeneous soil and the average soil moisture in wetted volume was larger in original layered soil than in homogeneous soil. (2) Four combinations of dripper discharge and spacing (2.71·h~-1V30cm, 2.71· h~-1V50cm, 1.41·h~-1V30cm and 1.41·h~-1V50cm, the designed wetted percentage was 81%, 73%, 65% and 42%, respectively) had no significant effects on the growth of cucumber under the same irrigation amount and frequency in greenhouse. The evapotranspiration, crop coefficients and water requirement coefficients of cucumber under drip irrigation were also estimated. In view of water use efficiency and investment of drip irrigation system, the smaller wetted percentage was recommended to the irrigation system for cucumber with ridges grown in greenhouse. (3) Four designed wetted percentage (78%, 56%, 39% and 26%) had no significant effects on the leaf water potential, stomatal resistance and other physiological index of almond in greenhouse under the same irrigation amount and frequency.
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