1. A flexible disk (7) for installation with the possibility of rotation on the holder (2) of the coulter of the disk coulter (1) relative to the cutting disk (5) for opening the arable layer (A), and the flexible disk (7) is arranged to be installed with the possibility of rotation so that it overlaps the cleaned surface (10) of the cutting disk (5), characterized in that the flexible disk (7) is flexible with the possibility of elastic deformation and in its plane of rotation has a maximum removal (D) of the edge and different from it minimal edge removal (d). 2. Disc coulter (1) with provided for supplying seed and / or fertilizer provided between the cutting disc (5) and at least partially flexible disc (7) output section (9), with the coulter holder (2) for installation with the possibility rotation of the cutting disk serving for opening the arable layer (A) of the cutting disk (5) and with the flexible disk (7) facing the output section (9) of the cleaning side (12) of the cleaning side (12) of the cutting disk (5), characterized in that it is flexible the disk (7) in its plane of rotation has a maximum removal (D) of the edge and distinct minimum removal (d) of the edge. 3. A disc coulter according to claim 2, in which the flexible disc (7) in its plane of rotation has at least mainly, primarily completely, a convex, primarily oval, preferably elliptical, external contour (11). A disc coulter according to claim 2 or 3, wherein the flexible disc (7) is made of polymer, primarily at least predominantly of thermoplastic, preferably at least predominantly of thermoplastic elastomer. The disc coulter according to claim 2, wherein the floppy disk (7) is1. Гибкий диск (7) для установки с возможностью вращения на держателе (2) сошника дискового сошника (1) относительно режущего диска (5) для вскрытия пахотного слоя (А), причем гибкий диск (7) выполнен с возможностью расположения с установкой с возможностью вращения таким образом, что он перекрывает очищаемую поверхн
