The introduction of technological solutions in agriculture allows reducing the use of resources and increasing the production of the crops. Furthermore, the quality of the water for irrigation can be monitored to ensure the safety of the produce for human consumption. However, the remote location of most fields presents a problem for providing wireless coverage to the sensing nodes and actuators deployed on the fields and the irrigation water canals. The work presented in this thesis addresses the problem of enabling wireless communication among the electronic devices deployed for water quality and field monitoring through a heterogeneous communication protocol and architecture. The first part of the dissertation introduces Precision Agriculture (PA) systems and the importance of water quality and field monitoring. In addition, the technologies that enable wireless communication in PA systems and the use of alternative solutions such as Internet of Underground Things (IoUT) and Unmanned Aerial Vehicles (UAV) are introduced as well. Then, an in-depth analysis on the state of the art regarding the sensors for water, field and meteorology monitoring and the most utilized wireless technologies in PA is performed. Furthermore, the current trends and challenges for Internet of Things (IoT) irrigation systems, including the alternate solutions previously introduced, have been discussed in detail. Then, the architecture for the proposed system is presented, which includes the areas of interest for the monitoring activities comprised of the canal and field areas. Moreover, the description and operation algorithms of the sensor nodes contemplated for each area is provided. The next chapter details the proposed heterogeneous communication protocol including the messages and alerts of the system. Additionally, a new tree topology for hybrid LoRa/WiFi multi-hop networks is presented. The specific additional functionalities intended for the proposed architecture are described in the following chapter. It includes data aggregation algorithms for the proposed topology, an overview on the security threats of PA systems, energy-saving and fault-tolerance algorithms, underground El proceso de realizar esta tesis ha comprendido estos últimos años, en los que he crecido tanto personal como profesionalmente. Primeramente, la realización de este trabajo habría sido imposible sin el apoyo de mi familia, quienes me han ayudado a avanzar en los momentos más difíciles. Todo lo que he conseguido ha sido gracias a ellos y a su certeza de que era capaz de lograr todos los retos que se me presentasen. También les quiero agradecer a mis amigos su compañía y apoyo a lo largo de este periodo. No puedo más que agradecer inconmensurablemente la ayuda de mi director de tesis PH. D. Jaime Lloret Mauri, quien me ha guiado en mi trayecto por el mundo académico y me ha aconsejado en los momentos más difíciles. A su vez, le doy todo mi agradecimiento a mi director de tesis Pascal Lorenz por todo su apoyo.Asimismo, no puedo olvidarme de mis compañeros, co...