This study is an attempt for an automated irrigation system which enable the users to regularly supervise relative humidity of the soil at different sites through the entire agricultural field for more accurate setting up of irrigation cycles. The sensing unit is modeled on a feedback mechanism with centralized control system which measures relative humidity (RH) of the soil and controls supply of water to the field in a real time process. A wireless communication is established between the sensor as well as controlling unit and the sprinkler. In practice, the pump on which control action is to be taken is at a distance from the land. A data acquisition system with a PC interface using UART-USB is also built up to record instantaneous values of soil temperature.