Device for delivering at least a layer of compost and casing soil to a shelving for growing mushrooms, comprising a first conveyor, on which in a downstream direction are arranged a first hopper with a receiving opening for receiving compost and a dispensing opening for delivering a compost layer on the first conveyor and a second hopper with a receiving opening for receiving casing soil and a dispensing opening for delivering casing soil on the compost layer wherein at least one separator for separating in a direction perpendicular to the downstream direction at least two fractions of the layer of compost with casing soil.