The method involves carrying out a fragmentation of the continuous flow of the products or active materials in order to convert it into a discontinuous flow or spot deposit, the operation taking place at the same time as the deposit of the seed and in the same place. In the device intended for carrying out the method, the product or active material is delivered from an accessory distribution appliance adjusted in relation to the hopper containing the seeds, the fragmentation is carried from a mechanical disc (4) with chambers or cellular spaces (3), the said disc (4) being the sowing disc adapted or equipped with an attached piece, and the product or active material is introduced into the fragmenting disc only just before or during the ejection of the seed. <IMAGE>
