A method for granulating a slurry in a fluidized bed granulator having a main longitudinal direction from a seed end where granulation is initiated, to a product discharge end where granules are discharged from the fluidized bed granulator, including at least one fluidized bed compartment, an injection section and a granulation section, separated by a bottom plate including one or more injection nozzles, wherein a feed slurry is provided to the injection section, wherein a first fraction of the feed slurry provided to the injection section is injected into the granulation section through the one or more injection nozzles and a second fraction of the feed slurry, being the remainder of the feed slurry, is passed through the injection section without being injected into the granulation section. A fluidized bed granulator for the granulation of slurries for fertilizer products such as UAS according to the method of the invention.