UAV-based precision agriculture: Optimization of payload parameters for foliar application in paddy cultivation

Unmanned Aerial Vehicles (UAVs) are revolutionizing precision agriculture by offering significant benefits, including reduced labour requirements, minimized crop damage, and enhanced application uniformity. This study focuses on optimizing UAV payload parameters for variable rate foliar application in paddy cultivation, addressing the critical need for precise agrochemical distribution in rice farming. A field trial was conducted during 2023-2024 at Farmer field, Kancheepuram, Tamil Nadu, India. The experiment involved four treatments: T1 (10 L/acre), T2 (8 L/acre), T3 (7 L/acre), and T4 (6 L/acre), with the development of a mathematical model using MATLAB, which was further validated under real-time field conditions. This ensured the practical feasibility of the optimized spraying parameters and established the relationship between Pulse Width Modulation (PWM) settings and flow rates. The study evaluated payload dispensing accuracy across varying field sizes, revealing that T2 achieved the highest accuracy of 98.08% over 0.13 acre, followed closely by T4 with 98.04% over 0.17 acre. Conversely, T3 displayed the lowest accuracy at 93.20% over 0.21 acre. The overall dispensing accuracy surpassed 95%, demonstrating exceptional precision in spray deposition and droplet distribution. Additionally, flight mission accuracy remained consistently high, with minimal deviations from planned paths, as confirmed by 3D flight path visualizations. These findings underscore the variability in performance based on application rates and field sizes, offering critical insights into UAV-based agrochemical applications. This research contributes valuable knowledge toward improving the precision, efficiency, and resource utilization in paddy cultivation.