Development and Evaluation of Arduino-Based Automatic Irrigation System for Regulation of Soil Moisture

In cities, green infrastructure has been used to mitigate flood risk, improve water quality, and harvest precipitation as a water source. Effective maintenance of green infrastructure requires optimal irrigation of plant root systems during the prolonged drying period. Based on the measurement of soil moisture, various drip irrigation systems have been developed. Surface irrigation, however, has the disadvantage of loss of soil moisture through evaporation. In addition, the growth of plants is mainly dependent on subsurface soil moisture, especially within the root zones. Therefore, there is a need to develop an automatic system regulating soil moisture at different depths. In this study, an Arduino-based irrigation control system was developed to regulate the volumetric water contents of soil within a certain depth range. A one-dimensional soil column test was conducted to demonstrate its performance. The test results show that the system enabled the regulation of soil water content within the specified range (12–20%) with an error of 2%. The error was further minimized by recalibrating the upper limit of the system. This study provides an improved green infrastructure irrigation system to control the moisture distribution within the soil subsurface.