Due the industrial development many countries facing a shortage of farming land. Finding enough manpower to carry out the necessary agricultural activities is also a major concern. With the limited farming land and workforce, the agriculture sector is expected to produce more to meet the requirements of a large population. Technology can support the agriculture industry in various ways to improve productivity. The use of advanced technologies such as the Internet of Things, machine learning, robotics, blockchain, etc. in the agriculture industry to improve productivity more efficiently is known as smart agriculture. This paper gives an overview of various methods in practice for smart agriculture and the current challenges in this area to which researchers can contribute. A detailed analysis of the existing methods is done in this study.