Compensation for nutrient deficit in NFT hydroponic systems

Abstract

The analysis of nutrient deficiencies in an NFT hydroponic system is essential for proper crop development. Since nutrient availability is crucial to ensuring that plants receive the necessary nutrients for their growth, it is important to implement strategies that allow efficient management and real-time control of nitrogen (N), phosphorus (P), and potassium (K) concentrations, as well as water supply, to compensate for nutrient deficiencies. To dose the deficit, an ON-OFF control system was implemented, which is activated based on the maximum deficit level set by the user. Sensors continuously monitor the pH levels of the circulating solution and the reservoir level to ensure that the system activates upon detecting the minimum threshold, compensating for the missing amounts of nutrients and water through flow sensors and solenoid valves that regulate the passage of solutions and water. The system includes a monitoring mechanism that allows users to check the crop’s status and take corrective actions in case of any system failure. Additionally, the data stored on a microSD card enabled a statistical analysis, which determined that the dosed amounts differed by 5% due to the limitations of the sensors used. However, compared to a system without automatic regulation, it was found that N, P, and K concentrations remained more stable, which favored lettuce growth and reduced resource waste.