An Intelligent Internet of Things (IoT)-Controlled Vermicomposting System for Circular Urban Agriculture: Enhancing Water Hyacinth Valorization and Vertical Crop Production
Abstract
Efficient vermicomposting requires stable substrate moisture; however, conventional timer-based irrigation cannot respond to actual moisture conditions, potentially resulting in inefficient water use and suboptimal biological decomposition. Moreover, integrating real-time Internet of Things (IoT)-based moisture control with water-hyacinth vermicomposting and subsequent vertical crop production remains insufficiently investigated. This study developed an intelligent Internet of Things IoT-controlled vermicomposting system integrated with vertical farming for circular urban agriculture. Water hyacinth (Eichhornia crassipes) and cow manure were used as feedstocks, while an ESP32-based platform provided real-time monitoring and automated irrigation. A 2 × 3 factorial experiment evaluated two irrigation strategies and three substrate compositions based on water consumption, decomposition, earthworm biomass, plant growth, and water-use efficiency. Moisture-controlled irrigation reduced water consumption by 13.2–23.1% compared with timer-based irrigation. The best-performing treatment, combining moisture control with the balanced substrate composition (Ratio 2), achieved 77.0% decomposition efficiency, an earthworm biomass increase of 87.8 g, lettuce height of 31.0 cm, 19.1 leaves plant-1, fresh biomass of 486 g plant-1, and water-use efficiency of 12.15 g L-1. The integrated system provides a resource-efficient approach to water conservation, water-hyacinth valorization, and urban crop production.
