Abstract: The air seeder normally passes the contents of its hopper through metering devices that regulate the volume of materials moving into the transporting air streams of the machine, but the hopper is also provided with a series of normally closed drainage apertures which may be selectively opened when it is desired to rapidly dump the hopper contents instead of relatively slowly metering them to the air streams. When the apertures are opened, the hopper contents bypass the metering devices and gravitate directly into the air streams which can be quickly and easily diverted to a cyclone separator that exhausts the air from the streams and concentrates the particles for collection or storage.