This paper is designed to develop an automatic water supply system in agriculture which automatically switches the pump motor ON/OFF by sensing the humidity content of the soil. In the farming field, use of a suitable method of irrigation is important. The advantage of using this method is to reduce human intervention and still ensure proper irrigation to increase the productivity and quality of the soil.it results in decreasing the use of pesticides in the agriculture field. In this, we are using an 8051 series microcontroller which is set to receive the input signal of changing moisture condition of the soil through the sensing procedure. Once the microcontroller receives this signal, it generates an output that drives a relay circuit for operating the water pump. If the moisture content is very low, then the motor is automatically driven to on state. A Wi-Fi modem is interfaced to the microcontroller to send the current status of the soil and water pump. These circuit connections are all connected to relay circuit to drive the motor. This concept is more improving by integrating IoT(internet of things) technology, such that whenever we want the water pump switches ON/OFF, the concerned person or the farmer using this system get to know the status about it through the web page by using IoT regarding the status of the pump.