PROBLEM TO BE SOLVED: To provide an opening and closing apparatus for irrigation, which does not require a power supply, is inexpensive, is readily miniaturized, is usable for irrigation on a large scale, can automatically supply water for a long period of time and is automatically operated, further, in irrigation of a wide agricultural land, a park, etc., adjustment in water supply responding to difference in drainage depending upon places, kinds of plants can be carried out by a simple piping, greening on places such as wall surface of concrete, etc., conventionally having difficulty in greening can be performed, through the above- mentioned purposes, an evil influence in soil, crop and plant by excessive irrigation is lightened and food shortages can be avoided while preventing the environmental deterioration progressing on a global scale as the ultimate purpose. SOLUTION: This opening and closing apparatus is characterized in that a water supply pipe is automatically opened and closed by using the pressure of a volume expansion by a water absorption body housed in a container with which water can be permeated through at least a part of the container.
