An air seeder cart apparatus has a primary container assembly with a plurality of primary product containers, with primary fill hatches at tops thereof. An air distribution network comprises product conduits and primary metering devices that dispense agricultural products from each primary product container into one of the product conduits. A secondary product container is mounted on a side of the primary container assembly and has a secondary fill hatch much lower than the primary fill hatches, and a secondary metering mechanism dispenses product from the secondary product container into one of the product conduits. The secondary product container is convenient for receiving bagged agricultural products from a low truck bed. Unopened product bags may be stored on a grate inside the secondary product container so they will be available if required. Weighing of product in the container can be provided.