The present invention relates to a liquid supply apparatus for supplying a liquid, A first body connected to the liquid supply unit and having a first space therein in which liquid supplied from the liquid supply unit is introduced A protrusion formed inside the first body and protruding into the first space to form a blocking hole A second body disposed in the soil and connected to the first body and having a second space formed therein, the second space being selectively connected to the first space through the blocking hole A polymer disposed in the second space and expanding by absorbing moisture of the soil Wherein the polymer is fixed on the upper side of the polymer, the outer circumference of the second body is in contact with the outer surface of the second body to prevent the liquid passing through the blocking hole from being directly absorbed by the polymer, A cover that blocks the blocking hole when the polymer is expanded And a guide stick fixed on the cover and guiding the movement of the cover inserted in the blocking hole, wherein liquid passing through the blocking hole is discharged to the soil from the first body or the second body And the second body is formed with micropores through which the moisture of the soil can move, and when water in the soil is reduced and moisture in the polymer moves to the soil through the micropores, Wherein the polymer is expanded when the moisture of the soil is transferred to the polymer through the micropores as the polymer is shrunk and the moisture of the soil is increased so that the polymer is expanded.본 발명은, 액체를 제공하는 액체제공부 상기 액체제공부와 연결되고, 상기 액체제공부로부터 제공받은 액체가 유입되는 제1공간이 내부에 형성된 제1바디 상기 제1바디의 내부에 형성되며, 상기 제1공간으로 돌출되어 차단홀을 형성하는 돌출부 토양에 배치되고, 상기 제1바디와 연결되며, 내부에는 상기 차단홀을 통해 상기 제1공간과 선택으로 연결되는 제2공간이 형성되는 제2바디 상기 제2공간에 배치되어 상기 토양의 수분을 흡수하여 팽창하는 폴리머 상기 폴리머의 상측에 고정되고, 상기 제2바디의 내면과 외주가 접촉되어 상기 차단홀을 통과하는 액체가 상기 폴리머로 직접 흡수되는 것을 방지하며, 상기 폴리머가 수축될 때 상기 차단홀을 개방하고, 상기 폴리머가 팽창될 때 상기 차단홀을 차단하는 커버 상기 커버의 상측에 고정되고, 상기 차단홀에 삽입
