An apparatus for depositing a particulate material onto mushroom compost has a distributor box configured to receive the particulate material, such as mushroom casing, and a moving belt that is fed from a roller into the bottom of the box and exits from a discharge opening of the distributor box. A net pulley roller associated with the moving belt is pulled to advance the moving belt. A ribbed roller mounted for rotation at or near the discharge opening of the distributor box scrapes the particulate material out of the distributor box and deposits the particulate material onto the top surface of the moving belt. The particulate material then rides on the top surface of the moving belt until it drops off the belt onto the mushroom compost at the belt reversal point.
