DYNAMIC MODELING, CONTROL AND VERIFICATION FOR CITRUS VARIABLE-RATE TECHNOLOGY (VRT) FERTILIZATION

Precision farming also known as site specific crop management is a technology where the farmer takes into account the variability within a field to determine the optimal inputs for the crop in order to maximize the profitability through optimizing the use of fertilizers by Variable-Rate Technology (VRT). This research provided the citrus growers of Florida a performance evaluation of all the commercial VRT fertilizer applicators available. The project also suggested new analytical methods to the VRT controller manufacturing industry to mathematically model the hydraulic components and their behavior and obtain tuning gains to implement in the algorithm of the controller to provide near to optimal performance. Experiments were conducted to prove that this method increased the performance of the VRT applicator with the same existing hardware. By implementing this, the grower is able to obtain economic gain and at the same time contributes to the reduction of environmental pollution.