Development and Evaluation of an Automated Alternate Wetting and Drying System in Rice Cultivation for Water Management

To overcome the challenges posed by climate variability on food security, it is imperative to reduce agricultural water usage and check release of greenhouse gases. This study aims to develop and evaluate an automated alternate wetting and drying (AAWD) system to reduce water usage and methane emissions from fields of rice, which is cultivated in a major part of the land in India. The developed AAWD system incorporates ultrasonic sensors, an ESP32 microcontroller, and the Blynk application for the real-time water-level monitoring and automating irrigation applications. The system is programmed to initiate irrigation when the water level drops up to 15 cm below ground surface and cease irrigation when the water storage depth extends beyond 5 cm from ground surface. Although improvements in plant growth parameters were not statistically significant under the AAWD system, the system effectively conserved water by precisely controlling irrigation intervals and water levels, resulting in a remarkable reduction of approximately 50% to 70% in water usage. The cost analysis confirmed the AAWD system as a cost-effective solution with about 18% improvement in benefit-cost ratio in comparison to flood irrigation for sustainable rice farming, with the potential to enhance both environmental and agricultural outcomes. Furthermore, the study utilized a sensor-based gas chamber equipped with an MQ4 sensor to accurately measure methane concentrations. Results showed that the AAWD system substantially reduced methane emissions, with levels dropping to 0.55 ppm. This reduction not only boosts the sustainability of paddy cultivation but also contributes to the global efforts in mitigating greenhouse gas emissions. The AAWD system also fostered continuous and healthy crop growth, indicating a strong potential for high grain yields at harvest.