A low-profile particulate handling assembly is provided for use in conjunction with a downstream treating device, such as a seed treater unit. The assembly includes a plurality of juxtaposed particulate bins and a surmounting turret assembly designed to successively deliver particulates to the bins. The particulates within the bins are delivered to the downstream treating device through respective lower outlets each equipped with an adjustable slide gate assembly and a lower, multiple-chute assembly. Preferably, each bin has a top wall which in plan configuration approximates a sector of a circle, planar sidewalls, and downwardly tapered, arcuate sidewall structure leading to the lower outlet; in this fashion, the bins can be grouped with the sidewalls in close adjacency, and with the outlets located to feed into a single inlet of the downstream treating device.