Agricultural seeding machine

Disclosed is a seeding machine (14) comprising: means for generating a reference signal (84); multiple row units (24, 201, 202, 301, 302), at least one row unit (24, 201, 202, 301, 302) having: a seed metering device (26) providing a metering action to a plurality of seeds; a drive (64) for the seed metering device (26) and a sensor (80, 94, 96, 98, 100, 180) adapted to sense a seed meter parameter, characterized in that the seed meter parameter relates to seed location in a furrow beneath the row unit (24, 201, 202, 301, 302) and the sensor generating an index signal (88); and control means for receiving the index signal (88) from the sensor (80, 94, 96, 98, 100, 180) and for receiving the reference signal (84), the control means determining a relationship between the index signal (88) and the reference signal (84) and the control means being operably coupled to the drive (64) for altering the metering action of the seed metering device (26) to establish a desired relationship between the index signal (88) and the reference signal (84). Further disclosed is a method for operating a seeding machine (14), including coordinating the placement of seed planted by multiple row units (24, 201, 202, 301, 302) of a planter.