The explosion in human population has left researchers scrambling for solutions on how to feed the world. Furthermore, rural-urban immigration has on the one hand left the farms in the rural areas devoid of farmers and on the other hand has left the urban areas over-populated. Hydroponics is a form of agriculture where crops are grown without soil. This technique allows the farms to follow the farmers to the urban area. In addition, the fact that no soil is needed, allows hydroponic system to be stacked vertically (also known as vertical farming) to save space. The final frontier in hydroponics is automation. It will allow one farmer to work more than one job and cultivate more than one farm simultaneously. This paper provides a comprehensive survey on smart hydroponic system developed to date.

Researchers have associated agriculture and food processing with adverse environmental impacts like; falls in the underground freshwater table, energy consumption, and high carbon emission. These factors have the worst effect on developing countries. Therefore, there is a need for on-demand food production techniques that require minimum resource utilization. For these reasons, scientists are now focusing their attention on hydroponics. Hydroponics is the process of growing crops without the use of soil. However, different components of the system need to be closely monitored and controlled. In this paper, we compared the performance of an automated hydroponic system using cluster-based wireless sensor networks against a multihop-based one. We used Simponics for the simulation. It is a simulator based on the OMNET++ framework. Simulation results show that both latency and energy overhead of the multihop network increases with the number of nodes. However, they stay constant on a cluster-based network.