Abstract: A compost supplement spreader for delivering supplement to the top of an elongated compost pile, the spreader being formed of a frame having spaced apart sides, wheels mounted on the frame for movement of the frame on the earth with the compost pile being positioned between the frame sides, a hopper elevationally supported between the frame sides, the hopper having a lower position whereby supplement may be deposited in the hopper open top and having an upper operating position whereby the hopper bottom clears the top of the compost pile and a conveyor belt in the bottom portion of the hopper for controllably discharging supplement from the hopper onto a compost pile.