PROBLEM TO BE SOLVED: To provide a new member for subirrigation and an underground subirrigation system using it and provide a member for subirrigation and an underground subirrigation system using it, capable of preventing winding of a root.SOLUTION: A member 10 for subirrigation including an impervious part 12 and a water permeable part 14 is laid under the ground in use. The impervious part 12 is formed like a groove with the upside opened by material quality having water permeability. The water permeable part 14 is formed of a material having water permeability, and both side edges thereof are integrated with the impervious part 12 to form a water permeable space 26 extending in the longitudinal direction on the inner inside surface of the impervious part 12. According to the invention, a root can be prevented from winding around the water permeable part forming the water permeable space, so that in cultivation or harvesting plants, the member for subirrigation can be prevented from being pulled out together with the winding root to break an underground subirrigation system.
