Akdemir, BahattinSağlam, CihangirAtar, Eyup SelçukTuren, NailÖzyürüyen, Levni Can2023-05-062023-05-0620220014-03091439-0302https://doi.org/10.1007/s10341-022-00800-9https://hdl.handle.net/20.500.11776/12211The objective of this research was to develop a machine to spread three different mineral fertilizers at the same time at a variable rate if required. A multi-fertilizer spreader machine with three hoppers, a variable rate controller, a laboratory test software and a prescription map software was developed. The variable rate controller consists of three servo motors, drivers, electronic control card, MOXA wireless NPort communication, and software for spreading three different mineral fertilizers. Fertilizers were metered by specially designed fluted rollers driven by three servo motors. The variable rate controller changes the speed of fluted rollers to change the fertilization rate according to the coordinates. The amount of distributed fertilizer for each grid is set up by prescription map. During fertilization, the amount of fertilizer for each position of GPS was saved by Prescription Map Software . This software can also calculate some data such as tractor tracks in the orchard, distances, time consumed for fertilization and turning, time to enter and exit from grids based on GPS data. The application rates of different chemical fertilizers were determined on different scales of the control system by laboratory tests of the developed machine. Materials were olive orchard, multi-fertilizer spreader with variable rate controller, and laboratory/workshop test programme. Laboratory and field tests of the developed machine for different fertilizers and variable rate applications for olive production were analysed and evaluated. Work performance (tree/h, and da/h) of the developed fertilizer spreader machine was determined. Effective capacity and efficiency were calculated. Modifications related fluted roller, furrow opener and control system were performed to solve mechanical, electrical and software problems of the prototype machine, and the variable rate fertilizer control system was tested through the laboratory and field tests. The developed machine and variable rate controller were operated successfully to apply fertilizers in the olive orchard.en10.1007/s10341-022-00800-9info:eu-repo/semantics/closedAccessOlive growingFertilizationVariable rate applicationMineral FertilizerPrecision farmingArticleQ3WOS:0009058465000062-s2.0-85145189041Q3