Method of operating an agricultural machine, the agricultural machine comprising: a structural member, at least one drilling unit comprising: a support device, a seed metering device to distribute seeds to a drill furrow in the ground across which the agricultural machine moves, wherein the drilling unit is movably connected with the structural member and the seed metering device is fixedly connected with the support device of the drilling unit, the seed metering device comprising: a seed metering element that, by means of a driving device, is arranged to transport seeds to a seed metering line, a chamber for seeds, which chamber is arranged to be supplied with a positive pressure from a pressure-creating member comprised by the agricultural machine, wherein the seed metering element constitutes a wall limiting the chamber and has holes or recesses which connect the chamber with the surroundings to develop a pressure difference and thereby attach and transport seeds at said holes or recesses of the seed metering element, wherein the method comprises the step of supplying the positive pressure from the pressure-creating member of the agricultural machine to the chamber; characterized in that the seed metering line has an inlet in the chamber; and in that the method further comprises the steps of utilizing the positive pressure that creates the pressure difference for the attaching and transporting the seeds to create an air flow in the seed metering line; accelerating the seed by the air flow in through the inlet of the seed metering line after the seed has been released from the seed metering element; and air transporting the seed through the seed metering line from the seed metering element to a drill furrow more rapidly in comparison with free fall. a structural member, at least one drilling unit comprising: a support device, a seed metering device to distribute seeds to a drill furrow in the ground across which the agricultural machine moves, a support device, a seed metering device to distribute seeds to a drill furrow in the ground across which the agricultural machine moves, wherein the drilling unit is movably connected with the structural member and the seed metering device is fixedly connected with the support device of the drilling unit, the seed metering device comprising: a seed metering element that, by means of a driving device, is arranged to transport seeds to a seed metering line, a chamber for seeds, which chamber is arranged to be supplied with a positive pressure from a pressure-creating member comprised by the agricultural machine, wherein the seed metering element constitutes a wall limiting the chamber and has holes or recesses which connect the chamber with the surroundings to develop a pressure difference and thereby attach and transport seeds at said holes or recesses of the seed metering element, wherein the method comprises the step of supplying the positive pressure from the pressure-creating member of the agricultural machine to the chamber; a seed metering element that, by means of a driving device, is arranged to transport seeds to a seed metering line, a chamber for seeds, which chamber is arranged to be supplied with a positive pressure from a pressure-creating member comprised by the agricultural machine, wherein the seed metering element constitutes a wall limiting the chamber and has holes or recesses which connect the chamber with the surroundings to develop a pressure difference and thereby attach and transport seeds at said holes or recesses of the seed metering element, wherein the method comprises the step of supplying the positive pressure from the pressure-creating member of the agricultural machine to the chamber; characterized in that the seed metering line has an inlet in the chamber; and in that the method further comprises the steps of utilizing the positive pressure that creates the pressure difference for the attaching and transporting the seeds to create an air flow in the seed metering line; accelerating the seed by the air flow in through the inlet of the seed metering line after the seed has been released from the seed metering element; and air transporting the seed through the seed metering line from the seed metering element to a drill furrow more rapidly in comparison with free fall.