Automated Water Optimization System for Allium fistulosum Crops: A Low-Cost IoT Solution for Urban Agriculture

Abstract

This article presents the design and implementation of an automated irrigation system for urban crops of Allium fistulosum (chives), based on soil moisture sensors and a low-cost IoT architecture. The system uses an ESP32 microcontroller as the processing and communication unit, which collects real-time data from capacitive sensors and an ultrasonic sensor to estimate the available water level. Data is transmitted via HTTP requests to a Google Sheets spreadsheet, using Google Apps Script as the bridge between the hardware and the cloud. The system operates autonomously, activating water pumps when humidity levels fall below defined thresholds. Sensor calibration translated the analog readings into humidity percentages, ensuring an accurate and efficient response. The results demonstrate a 92.86% reduction in water use compared to manual irrigation, while maintaining optimal conditions for crop development. This solution represents an accessible, replicable alternative aligned with the principles of sustainability and automation in urban agriculture.