How to build full circuit of automatic soil moisture sensing and automatic switching of motor and automatic watering the crops. ...
We want to do our final year project on this topic
Please help to build the circuit

Develop an automatic irrigation system that turns the pump motor on / off by detecting soil moisture content. In the field of agriculture, the use of an appropriate method of irrigation is important. The advantage of using this method is to reduce human intervention and still ensure adequate irrigation. The project uses an 8051 series microcontroller that is programmed to receive the input signal from the variable soil moisture condition through the detection array. This is achieved by using an operational amplifier as a comparator which acts as an interface between the detection arrangement and the microcontroller. 

Once the controller receives this signal, it generates an output that drives a relay for the operation of the water pump. An LCD display is also connected to the microcontroller to display the status of the ground and water pump. The detection arrangement is made using two rigid metal bars inserted in the field at a distance. The connections of the metal rods are connected to the control unit. The concept in the future can be improved by integrating GSM technology, so that each time the water pump is turned on / off, an SMS is sent to the person concerned regarding the state of the pump. We can also control the pump via SMS.