The spreader has a distributing blade (2) with an upstream end portion intercepting a product falling on a rotary disc. The blade channels and directs the intercepted product to its downstream end portion. The blade is subdivided into two superposed channels (C1, C2) of unequal lengths separated by a longitudinal and horizontal partition (5) which extends from the upstream edge of the blade to the downstream end of the channel (C2). The partition separates the product flow falling on the disc by its upstream part. The downstream part of the blade extends beyond the channel (C2).
