A seeding heart for a single-grain seeding machine comprising a seeding disc rotatable in a rotational direction (R) with a large number of seeding holes distributed concentrically with respect to the seeding disc along at least one seeding hole circle and at least one agitator shaft for the movement of the seed, said agitator shaft being disposed in a holding section for holding the seed on the seeding holes of the seeding disc, characterised in that the agitator shaft is constituted replaceable in a modular manner. A single-grain seeding machine including the seeding heart.
