Proper irrigation management, particularly for water-sensitive plants, ensures long-term productivity. Combining a low-cost sensor with the Internet of Things (IoT) offers a promising solution for accurately monitoring soil moisture levels in the root zone of plants. This technology empowers on-demand irrigation, significantly reducing the need for human involvement. An IoT-based, precise monitoring system was developed to cultivate green beans within a greenhouse. Three irrigation levels, 100%, 80%, and 60%, and two irrigation systems, surface (SDI) and subsurface (SSDI) drip irrigation, were compared to assess which level and irrigation system increased in green bean yield and water use efficiency (WUE) under greenhouse conditions. The experiment was conducted at El-Sharkia governorate, Egypt, at latitude 30.416667° N and longitude 31.639833° E. during the winter season of 2022-2023, planting on 25 October 2022, and last harvesting on 14 March 2023. The results revealed that SSDI outperformed (SDI) re-garding of green bean yield. The results indicate that (SSDI) enhances average green bean yield by approximately 11% compared to (SDI) for both full and deficit irrigation treatments. The average green bean yields are 26.844 and 30.156 t ha^-1 for SDI and SSDI, respectively. Additionally, SSDI demonstrated superior WUE compared to SDI, particularly under deficit irrigation conditions. These results suggest that SSDI, coupled with an irrigation treatment of 80% ETc, can maximize green bean yield while optimizing WUE. The productivity reached 33.614 t ha^-1, and the seasonal water use value was 262.5 mm/season, while the WUE was 12.81 kg/m³. In regions facing water scarcity, implementing SSDI strategies that involve a 60% reduction in ETc throughout the entire growing season could be a viable approach in the greenhouse. The productivity reached 32.466 t ha^-1, and the seasonal water use value was 206.5 mm/season, while the WUE was 15.73 kg/m³. Therefore, the combination of Internet of Things technology, SSDI system, and deficit irrigation practices of 80% can enhance both WUE and green bean yield under greenhouse conditions, particularly in water-scarce regions.