When you make a farming plot of lets say, 10x10. Farmers will make the little hills spaced 1 block apart from each other, but if you make 1x10 strips they will make the hills right next to each other, getting you 2x more food. I don’t know whether this is a bug or not, but I found it useful and I’m sure you will too.
Once water is required for farming (I think it’s planned for Alpha 12-13), then the furrows will be required, and will need to be watered. Until then, though, compact-farm away!
Personally, it’s just easier for me to make 2 10x10 farms than to try to plant them really small. The Hearthlings really don’t have to walk very far to get to the second plot, and the only “extra” work they do is tilling the furrows - which they only do once.