| dc.description.abstract | Variable rate fertilizer application system is one of the key technologies in intelligent machines that are required in the implementation of precision agriculture or precision farming. The mentioned machines should should be accurate, flexible in operation and could be able to change dose quickly. Conventional fertilizer applicator that uses the tractor’s PTO was not suitable for this purpose because it serve single dose uniform rate only. It was not flexible in changing the dose, and also had disadvantage where the rate of fertilizer output is influence by the speed tractor. In this research an electronic metering device for variable rate fertilizer application wass developed. The metering system base on star type rotor which was directly rotated by the DC motor. The speed of the motors was controlled digitally-based 8-bit AVR microcontroller module 128. The system developed was able to precisely metered the fertilizer dan change dosage appropriately and quickly, it also allows the recording of data during the process of application. In field application, its position in the field is monitored using DGPS. Test results showed that the metered fertilizer has a linear relationship to rotation of the rotor and consistent along with time. The output also proportional to single rotor or double rotor operation. Operating with a single rotor with urea fertilizer gave calibration value 0.794 g / s / rps with coefficient of determination more than 0.999, while operating with double rotor gave calibration value of 1.513 g / s / rps with coefficient determintion of more than 0999. The development of this prototype is expected to support national technology capabilities upon the adoption of precision farming practice in the future. | en |
