1. A pneumatic seed dispenser, comprising: a housing comprising an inner chamber； a disk mounted in said housing for rotation about an axis and having a plurality of seed cells spaced radially around an axis to hold seeds； and an adjustable piece feeding device to exclude a plurality of seeds from said seed cells, wherein said piece feeding device comprises two blades adjacent to the seed cells and at least partially surrounds them； while the blades of the piece feeding device can simultaneously be adjusted so that the first blade moves progressively radially from the axis, and the second blade is radially to the axis, and so that the first blade can also be adjusted radially to the axis, and the second blade is radially from the axis. 2. The pneumatic seed dispenser according to claim 1, wherein the first blade is located radially inside from the seed cells, and the second blade is located radially outside of the seed cells. The pneumatic seed metering device according to claim 1, further comprising a curved rim portion near the first blade and configured to substantially coincide with the curvature of the disc. The pneumatic seed metering device according to claim 1, wherein the first scapula contains at least one ramp extending from the scapula and to the axis. The pneumatic seed metering device according to claim 1, wherein the second blade contains at least one slope extending from the blade and from the axis. The pneumatic seed metering device according to claim 1, further comprising a rotary control device operably connected to the first and second blades, wherein the rotation of the rotary control device controls the distance between the first and1. Пневматический дозатор семян, содержащий:корпус, содержащий внутреннюю камеру；диск, установленный в указанном корпусе с возможностью вращения вокруг оси и имеющий множество семенных ячеек, разнесенных радиально вокруг оси для удерживания семян； ирегулируемое устройство поштучной подачи для исключения множества се
