A very simple way (it does need a bit more space to work) and it doesnt need any mods its like this.
1.st make a looooooooooooooooooong field (and be sure you have workbenches araund to prevent monsters from spawning)
Equip the cultivator and carrots.
Now just move back and spam click in line, while slowly going back (side to side holding A/D also works). Be sure you keep your eye on stamina.
I recomend using stamina only food so you can spam-click on ground faster.
You can quite easy plant 500+ seeds and not having to worry abauth any getting rotten.

Also having a field as straight as possible helps a lot, so investing some time mining off bumps on field can help you later.

Downside however, it may not look pretty, but its very effective time/food wise.
I usualy just make a portal somewhere in meadows with straight terrain, mine the side so mobs cant just run into the fields and start planting. Then i return every 2-3 days and start re-seeding again.