Adjustable seed meters having a first seed disk having first openings defined therein and a second seed disk having second openings defined therein adjacent to the first openings such that the first and second openings are alignable to form adjustable seed cells. Various embodiments have a plate adjustment drive system to rotate the first and second seed disks in relation to each other. Other embodiments relate to methods of automatically adjusting a seed meter during operation of the overall planting system.

Sowing element for precision agricultural seeders comprising a device for selecting the seed, of the type which is formed of a perforated disc having opposing faces that are subject to a pressure differential and a pressurisation device associated with the disc for applying the pressure differential to the faces of the disc, the pressurisation device including a pressurisation bell combined with the disc so as to pneumatically couple thereto in order to guarantee said pressure differential, wherein the bell is rotatably idle with respect to the disc.

A singulating meter apparatus comprising a seed disc operative to be rotated in a housing about a disc rotational axis with inner and outer rows of seed apertures defined by the seed disc. A singulator is arranged to protrude from an outer and inner side of both paths. A seed output port is operative to receive seeds from the seed apertures in the inner and outer aperture rows. In a single mode both rows are dispensed into a single seed conduit, and in a dual mode the seeds from each row are dispensed into individual conduits. A seed counting sensor is mounted on the seed output port counts the seeds passing through the seed output port in both the inner and outer seed conduits. A four row disc is also provided that as well has dual and single options.