I noticed that if you use a machine that cultivates AND sows, that the progression only counts for Sowing. You need to use just a cultivator to get this achievement.
For simplicity, use the Money Cheat Box Mod and then go buy field five, and the best cultivator you can get with a good tractor.
Set the hired help and let them do the field about 1.5 times and you should get this achievement.
If you put the speed on 120x.
Cultivate the field then
Sow the field then
Fertilize the field then
Harvest the field.
And you should have all achievements relatively quickly.
Hired workers count towards the total.
That's if you don't get the achievements from helping the farmers first, which you should do first on your path to 100%