As we know that Agriculture serves as the heart of Indian economy and half of the population in India survives because of agriculture is the main earning crops in India for this we want to make a smart agriculture system for easily farming and other processes. In this paper, advantages of IoT in Smart Farming and its applications are presented. Architecture of a fully automated agriculture system and a smart weather and Soil condition sensor are presented. Challenges in implementing an IoT based agricultural systems are highlighted. Durability of sensors and cost are mentioned.