Precision Agriculture for Cucumber Cultivation: An Internet of Things Approach
Abstract
Cucumber growers who irrigate by a fixed daily schedule routinely water a plant that is already wet, because the schedule cannot see the soil it is watering. This paper reports the design, hardware realisation, and field testing of an Internet of Things (IoT) control and monitoring system that replaces the schedule with a threshold triggered by an actual soil-moisture reading. A NodeMCU ESP32 microcontroller reads a capacitive soil-moisture probe, a DHT11 temperature and humidity sensor, and a light-dependent resistor (LDR) module, and switches a 12 V DC water pump through a relay whenever soil moisture falls below a 35% threshold; every reading is pushed over WiFi to a MySQL database and displayed on a role-based (administrator and gardener) web dashboard built in PHP and Morris.js. The control circuit was first modelled and verified in Fritzing before any hardware was built, the driver board was laid out and etched as a custom printed circuit board (PCB) in-house, and the completed unit was fitted to a potted cucumber plant for field trial. Over a two-day comparative trial, threshold-triggered automatic irrigation opened the water pump 3 times against 12 times for a fixed 4-times-daily schedule, while holding soil moisture within the same 35-60% band, a 75% reduction in pump activations for an equivalent moisture outcome. The prototype also survived an unplanned stress test: after heavy rain and a fungal leaf infection, the automatically irrigated plant recovered following a mancozeb fungicide application, continuing growth to the end of the 12-day observation window. The results support threshold-based, sensor-driven irrigation as a practical route to water saving in small-scale and home-garden cucumber cultivation, and the paper closes with a quantitative evaluation protocol, covering longer trial duration, larger plant samples, WiFi reliability, and pest and disease pressure, that should precede any larger deployment.