Controller for farmland humidity alarming and automatic irragation

The utility model discloses a controller used for farmland humidity alarming and automatic irrigation. In the utility model, the lower end of a rod body is connected and sealed with a multiporous pottery clay head, the upper part of the rod body is provided with a transparent air collecting chamber, the top end of the air collecting chamber is sealed by a rubber plug, one side of the air collecting chamber is connected with a vacuum meter with a switch structure, the vacuum meter is provided with two pointers, one of the pointers is a reading pointer, the other pointer is a presetting pointer, the same positions of the reading pointer and the presetting pointer are respectively fixed with a silvering contact, and the top of the presetting pointer is connected with a knob.