Increased cost efficiencies and ease of use make spinner-disc spreaders the primary method of applying fertilizers throughout much of the United States. Recently, advances in spreader systems have enabled multiple fertilizer products to be applied at variable application rates. This provides greater flexibility during site-specific management of in-field fertility. Physical and aerodynamic properties vary for fertilizer granules of different sources and densities, these properties in turn affect the uniformity of distribution. The purpose of this study was to evaluate the effect of fertilizer composition on distribution uniformity between independently metered and blended fertilizer sources, and determine the effect of metering type on spread of multiple products.  A spreader with a dual bin, and the ability to independently meter two products onto spinner-discs was used for this study. Prior to spreading fertilizer, particle analysis determined that the bulk density of diammonium phosphate (DAP), muriate of potash (KCl), and a blended fertilizer (10-26-26) were 1009, 1105, 1025 kg/m3, respectively. All three fertilizer sources were broadcast and nutrient distributions determined. Specifically, the DAP components of the patterns were analyzed for any changes across all three fertilizer sources. DAP only spread patterns differed from that of the independently metered and the blended mixture, while the independently metered and blended fertilizer patterns were almost identical. Pan collection test results showed independently metered DAP and potash spread patterns were not significantly different than the blended mixture. These results indicate that there is a need for dynamically changing spreader adjustments during a variable rate scenario.