Sowing seeds is often a pleasurable activity, it can become tedious or routine on a large scale.
It seems like it should be fairly easy to automate with a vacuum and a XY rack of some kind.
Or a conveyor belt system
You can get commercial systems:
And there is a couple of Arduino versions
This 3d printed version by Akash is up on Hackaday
Quotes for the Gear for vacuum bar
Sculptio £6 plus £4 shipping
iMaterialise £10