Development of an IoT-based automatic fertigation system

Fertigation supplies water and liquid fertilizer through the same channel to plants. Using drip irrigation set up for fertigation allows the root zone of the plant to be continuously supplied with nutrients and water throughout the farm season. Conventionally, fertigated systems are controlled using pre-set timers to turn on and off fertilizer injectors and irrigation pumps, and also to set the frequency and duration of supply. Therefore, fertigation management is usually based only on predictive algorithms or historical data, which may not be accurate for all situations. Development of a microcontroller-based fertigation management system within the Nigerian (Sub-Saharan Africa) region using a capacitive soil moisture sensor and a JXCT-IOT Frequency Domain Reflectometry (FDR) soil nitrogen sensor is presented. The sensors are placed in the soil around the root region of plants to enable a microcontroller to monitor the soil properties, determine how much water or nutrients the plant needs, and supply the amount needed through a drip irrigation framework. The tap water and urea solution are placed inside separate reservoirs and supplied to the plant through solenoid valves controlled by the microcontroller. Furthermore, an Internet of Things (IoT) client (Blynk IoT) was integrated with the fertigation system so that the fertigation process, as well as the soil state, could be monitored and controlled remotely. The data read from the sensors as well as the state of the solenoid valves were sent over the internet to be stored on the Blynk servers. A website and mobile (Android) dashboards were also created using the Blynk IOT platform to display the states of the valves and the sensor readings. The automatic fertigation system was found to be functional. The system keeps the soil moisture and nitrogen content between the recommended ranges: moisture content between 25% and 46% and nitrogen content between 20 mg/kg and 30 mg/kg for cucumber crops. Fertigation events occur every morning between 5 and 6 am.