Development of a machine vision-based walk-behind cotton fertilizer applicator

A machine vision-based walk-behind cotton fertilizer applicator was developed to overcome the challenges of conventional fertilizer applicators. Existing fertilizer applicators are associated with various operational challenges, such as excessive discharge rates, inconsistent distribution patterns, wastage of input, and increased weed growth. Field testing was conducted to assess performance parameters such as missing plant index, application uniformity, application accuracy, fertilizer saving, and field performance matrix. This applicator consists of a cotton detection system, an electronic control system, and an automatic fertilization system. The cotton detection system for image acquisition and recognition of cotton by ignoring the presence of weeds; an electronic control system regulates stepper of fertilization system as per the received cotton detected signal; and an automatic fertilization system delivers micro-granular fertilizer near the targeted cotton plant after rotating fertilizer metering unit via stepper motor. Cotton detection system, demonstrating high accuracy with bounding box losses of 2.14 percent and object losses of 1.56 percent over 100 epochs, proving its efficacy in real-time cotton plant detection. Minor deviations in delivery rates were noted, with Urea ranging from 5.59 percent to 8.9 percent and DAP from 6.89 percent to 9.25 percent. The ratios between left and right for Urea and DAP ranged from 0.89 to 1.05 and 0.90 to 1.04, respectively, with mean values of 0.95 for Urea and 0.97 for DAP observed. The machine vision-guided applicator achieved impressive accuracy in fertilizer application, consistently delivering between 90 percent and 93 percent with an average of 91 percent. The theoretical field capacity, actual field capacity and field efficiency ranged varied 0.07–0.14 hectare per hour, 0.045–0.078 hectare per hour, and 69.39 percent at 0.5 hectare per hour to 58.21 percent, respectively, across the speed from 0.5 to 1 kilometre per hour. This study successfully designed and implemented a precision cotton fertilizer applicator offering several key achievements: precise fertilization, adoptive fertilizer delivery, saving labor requirement and time, weed management, and application of advanced technology in agriculture.