A planting implement including a toolbar and a seed metering system supportedby the toolbar. The seed metering system includes at least one row unit. Eachrow unit includesa frame, an auxiliary seed hopper supported by the frame, a seed meter fluidlycoupled to theauxiliary seed hopper, and a vacuum fan fluidly coupled to the auxiliary seedhopper and theseed meter in a closed fluid system in which the vacuum fan recirculates airthrough the auxiliaryseed hopper and the seed meter.
