Development of a wireless sensor network based on electrochemical sensing nodes for smart hydroponic culture

The global population is expected to surpass 9 billion by 2050, forcing food production to double, especially in developing countries. Challenges such as limited arable land, climate change, water scarcity, and fossil fuel depletion threaten agricultural output. Hydroponic culture, a soil-free method of growing plants with nutrient-enriched water, offers a sustainable solution. It conserves water, reduces the need for pesticides, and enables higher productivity in smaller spaces. This paper explores the development of a wireless sensor network based on electrochemical sensing nodes focusing on monitoring nutrients concentration into the irrigation water: each sensing node employs a custom-designed gold-plated PCB electrode and a custom electronic interface. The system was tested using three commercially available nutrient solutions across various concentrations. Data analysis, including Principal Component Analysis (PCA) and Partial Least Squares Discriminant Analysis (PLS-DA), demonstrated the ability to discriminate between nutrient types and concentrations with maximum error, in the worst case, of 0.0443 mL/L. The results indicate that electrochemical sensing, combined with wireless connectivity, can significantly enhance the efficiency and precision of hydroponic systems, facilitating optimized nutrient management. Future research will focus on testing additional nutrient mixtures and evaluating the long-term stability of the sensing technology.