From Bret Devereaux’s excellent series on the history and mechanics of farming:
In places where seed-drilling devices weren’t available, seeds were sown by the broadcast method. The ground was plowed, then the seeds were thrown out over the ground (literally cast broadly; this is where our term broadcast comes from); the ridges created by plowing would cause most of the seeds to fall into the grooves (called furrows; thus a ‘furrowed’ brow being one scrunched up to create ridges and depressions that looked like a plowed field), creating very rough rows of crops once those seeds sprouted. Then the land is then harrowed (where our sense of ‘harrowing‘ comes from – seriously, so much English idiomatic expressions are farming idioms, for obvious reasons), typically with rakes and hoes to bury the seeds by flattening out the ridges (but not generally entirely erasing them) in order to cover the seeds over once they had been placed with very loose clods of earth.