SMART CLOSED-LOOP HYDROPONIC FARMING: AN IoT-BASED EDGE-INTELLIGENT FRAMEWORK FOR NUTRIENT MANAGEMENT AND WATER CONSERVATION

Hydroponic farming allows the growth of crop plants without any soil and provides them with nutrients through water. The technology is useful in situations where space is lim-ited or the growing conditions are easily controllable. However, its success is subject to strict control over water and nutrition supply. Control is complicated when the pH or EC changes, due to sensor drift, or firstly introduced nutrients are not yet mixed in the tank. A controller based merely on preset thresholds will react too quickly, while a cloud-based system would be less efficient in the case the internet connection is lost. This work integrates pH and electrical conductivity sensing, local processing of the data, and fuzzy-logic-enabled decision-making for nutrient application. The controller keeps track of the solution variables and implements the corrective measures within the specified boundaries, as well as controls the pumps for nutrient application while providing several very important functions locally even when the internet is absent. Flow measurements are included to have information about the inflow of the water, the recirculation process, and losses. The proposed system takes into account calibration, mixing time, limitations of the dosage, and maintenance of the sensors. The project’s summary in-dicates that the target of 95% water retention is a goal to be achieved experimentally, not an accomplished result. The paper discusses the architecture proposed, workflow of control, eval-uation indicators, and the points to be considered for the implementation of resource-efficient hydroponic systems.