India being developing country, agriculture is still the primary occupation of majority of people. Currently the supply and demand of agricultural products has not been controlled properly because of manually measuring the environmental parameters by the farmers. Hence, adaption of technology based farming is necessary to increase the revenue. Even the climatic changes and rainfall has been erratic over the past few decades. Lack of rainfall and excessive rainfall both are dangerous to the cultivation. The correlation analysis between the crop statistical information and agricultural environment information enhances the ability of the farmers to analyze the current condition and predict the future harvest. In this paper, the sensor technology and wireless network in integration with IoT has been studied and reviewed based on the actual agricultural system. Here a distributed wireless network of sensors is used to collect the real time data of the various environmental parameters. The microcontroller handles this data and triggers the actuators based on the threshold defined for a particular crop to control the water quantity. The data from the irrigation field is view via thing speak cloud.