A cart is towed behind a combine harvester for collecting corn cobs and includes a conveyer belt feeding into a system for separating cobs from residue to be discharged and a tank for receiving and transporting the cobs. An unload auger is provided from the tank to one side of the cart while the cart moves forward. Power for driving the cart is obtained from a chopper drive of the combine harvester. The separating arrangement includes a series of sequential blower fans for blowing air through the discharged material as it is discharged from a conveyor and into a spreading guide disperses the residue. The cobs are conveyed using a series of augers where the auger to flight distance is at least 2 inches and particularly a pair of augers feed the cobs through a front wall of the tank so as to push cobs upwardly into the tank.