Bump for a great idea, I was just thinking about this myself couple days ago. Heres some info if someone wants to jump on this. You could do a quest profile or plugin that would till "untilled soil", plant a seed, If its a "bursting" crop then harvest it, if not you would need to either code into the profile all those items above and a proper way to fix the soil then use the "Dented Shovel" to destroy the plant and repeat. Edit: Updated with about all the ID#s for white turnips
I will investigate this tomorrow and see if its possible with a QO profile. Sounds a bit complicated.
If you look at my post at the top of the page, I have just about everything laid out, npc IDs and what action is required if you get that type of crop etc if you really are gonna take this on ill be happy to work with ya in testing and get last few ids etc
I requested this a Time before, maybe try to search next time I think you can't handle this with a Profile, so better request a bot or a Plugin. You only need to do this on 1 Plant not at all 16. Because it is fully random if it get an Instant grow or not.