Development of a LoRaWAN IoT Node with Ion-Selective Electrode Soil Nitrate Sensors for Precision Agriculture

Abstract

Crop productivity is highly dependent on the availability of soluble nitrogen (N), e.g. nitrate, in soil. When N levels are low, fertilisers are applied to replenish the soil’s reserves. Typically the timing of these applications is based on paper-based guidance and sensor-based measurements of canopy greenness, which provides an indirect measure of soil N status. However this approach often means that N fertiliser is applied inappropriately or too late, resulting in excess N being lost to the environment, or too little N to meet crop demand. To promote greater N use efficiency and improve agricultural sustainability, we developed an Internet of Things (IoT) approach for the real-time measurement of soil nitrate levels using ion-selective membrane sensors in combination with digital soil moisture probes. The node incorporates state-of-the-art IoT connectivity using a LoRaWAN transceiver. The sensing platform can transfer real-time data via a cloud-connected gateway for processing and storage. In summary, we present a validated soil sensor system for real-time monitoring of soil nitrate concentrations, which can support fertiliser management decisions, improve N use efficiency and reduce N losses to the environment.

Review—Perspectives on the Roles of Real time Nitrogen Sensing and IoT Integration in Smart Agriculture

“…It not only facilitates sensor actuation if required but also processes data from the sensor circuit, prepares data for the IoT network, and establishes communication with a wireless modem to create the IoT network. 87,112,113,115,[157][158][159][160][161][162][163][164][165][166][167][168][169][170][171] In the following subsections, the specifics of the electronic circuit for both optical and electrochemical sensors will be explored, followed by a detailed examination of the computing system. This comprehensive approach aims to provide a complete understanding of the electronic system's functionalities for integrating N sensors into the IoT network.…”

Smart Sensors and Smart Data for Precision Agriculture: A Review

“…In [ 155 ], an innovative IoT approach to improving crop productivity through real-time monitoring of soil nitrate levels is presented. Traditionally, fertilization decisions are guided by paper-based methods and canopy greenness measurements, leading to suboptimal applications and environmental issues.…”

Ion-Selective Electrodes in the Food Industry: Development Trends in the Potentiometric Determination of Ionic Pollutants

“…Nitrate-selective sensors have extensively been reported in agriculture applications, given the increasing use of fertilisers, and the key role of nitrate in plant growth. Some examples of ion-selective electrodes applied to this field include soil contamination monitoring [188], and the monitoring of nutrient solutions in hydroponic cultures [189]. However, there is a shortage of ionophores for nitrate sensing.…”