In this CAREER project, the development of wireless underground sensor networks, which carries information through soil, is investigated. More specifically, the application of underground networking in agriculture is considered, where underground sensor networks promise significant reduction in water usage for irrigation. The objectives of this project are to establish the foundations of underground networking for the realization of underground sensor networks, develop hands-on educational tools, and provide experiences to facilitate the dissemination of these techniques to a larger audience including students and farmers. Communication performance in underground settings is significantly affected by the variations in soil conditions. Hence, the research activities are focused on revisiting the concepts of connectivity and interference under the influence of environmental factors such as soil composition, soil moisture, and depth. Moreover, a theoretical framework is developed to capture the spatial and temporal correlations in soil moisture for underground sensor networks, enabling the development of environment-aware communication protocols. The insights from these analyses are exploited to develop event-based cross-layer communication platforms that adapt to the environment in an energy efficient manner. Finally, an agricultural underground sensor network testbed is developed to evaluate and highlight the outcomes of this research. The educational components include bringing wireless sensor networking to the class, developing an interactive cyber-physical networking lab, and providing hands-on experiences for "little farmers". The realization of the underground networking techniques has the potential to transform the agriculture industry, as well as a broad range of applications including border patrol, perimeter surveillance, and toxic material monitoring.