Development of an Automatic Control Unit for Granular Fertilization of Field Crops

The precision application of granular chemical fertilizers plays a vital role in optimizing crop yield while minimizing environmental impact. This study presents the developed of an automatic control system for targeted fertilization within plant root zones. The system integrates the main frame, fertilizer hoppers, feeding mechanism and an automatic control unit. Field tests were carried out at four forward speeds (1.62, 2.11, 2.55, and 3.55 km/h), three different fertilizing distance (planting distance), and three sensor distance (15, 20, and 25 cm). The quality of the fertilization process performance was determined the following performance indicators: fertilizer distribution uniformity, energy consumption, and operating costs. The results revealed that decreasing the machine's forward speed improves machine efficiency and, as a result fertilizer distribution uniformity. Increased forward speed of the machine reduces fertilizer distribution uniformity. Best uniformity was found at a forward speed of 1.62 km/h and plant sensor distances of 20 cm. At planting distances of 20, 25, and 30 cm, fertilizer distribution uniformity was (91.8, 92.81, and 94.61%), respectively. The lowest and highest value for actual field capacity were obtained. For energy consumption, the lowest operating costs were 0.87 fed/hour, 5.73 kWh/fed, and 137.36 pounds/fed), respectively, at a forward speed of the fertilizer machine of 3.05 km/hour.