Abstract: A seed distribution system is provided for planters and drills wherein the distribution system includes a central hopper for supplying a plurality of seed metering units. A plurality of seed distribution units are mounted on a lower portion of the central hopper and each seed distribution unit includes a central tubular member defining an air column for entraining seeds to be distributed from the central hopper. A plurality of discharge outlets open into the air column for receiving seeds therefrom and for conveying the seeds through distribution tubes to metering unit bins associated with each of the seed metering units. In addition, each of the seed metering unit bins is provided with apparatus for adjusting the level of seed accumulated within the bin.