REFINEMENT AND EVALUATION OF AUTOMATED NUTRIENT MONITORING AND CONTROL SYSTEM FOR SPINACH IN HYDROPONICS

Abstract

A study was conducted to refine and evaluate an automated nutrient monitoring and control system for hydroponics. The research took place in a naturally ventilated polyhouse situated near the Precision Farming Development Centre, KCAET, Tavanur. The main objective of the study was to assess the effectiveness of the automated system. Within the polyhouse, a vertical hydroponic structure was installed, and various microclimatic parameters such as relative humidity, light intensity, and temperature were monitored both inside and outside the polyhouse throughout the study. Spinach was chosen as the crop and cultivated for a period of 14 days (2 weeks) using a nutrient solution as the growth medium. The nutrient solution parameters, including pH and Total Dissolved Solids (TDS), were closely monitored and maintained within the desired range. To regulate these parameters, solenoid valves were connected to four water bottles (containing pH up, pH down, Nutrient solution A, and B) as well as a water tank, ensuring precise control of the nutrient solution within the specified range. In order to streamline the hydroponic system, various sensors including pH, TDS, ultrasonic, and water flow were integrated with a microcontroller. This microcontroller played a crucial role in real-time monitoring and control of the system, enabling the activation of the pump and solenoid valves via a relay whenever necessary. To ensure proper mixing of the nutrient solution, an agitator was installed within the tank. The sensor readings were transmitted to a web server using a Wi-Fi module, which was connected to the microcontroller. This allowed the microcontroller to gather data from the sensors and transmit it to ThingSpeak, an IoT platform. Daily observations were made on relative humidity, light intensity, and temperature levels inside the polyhouse, revealing that they fell within the necessary range for a hydroponic system. The pH and TDS (Total Dissolved Solids) of the nutrient solution were continuously monitored and adjusted within the prescribed range using pH up, pH down, Nutrient A, Nutrient B, and water. Thanks to its IoT-based automation, this system offers smart monitoring capabilities, allowing users to conveniently access real-time information about its current state through an Android application. Consequently, cultivating plants at home has become more convenient. While the automated system was initially developed as a prototype, its scalability makes it suitable for large-scale crop cultivation.