I've a strong suspicion that scythe harvests do not grant farming xp.
Harvested >5000 wheat in first summer & fall, no levels gained; harvested ~15 Bok Choy from a small kitchen garden plot and ding!
I haven't been able to find any mention of this in the subreddit or wiki, but now I want to perform some Science! to confirm it.
Also, I have a hankering to suss out the optimal scarecrow coverage for a max-crops farm.
I'm working on the assumption that 100% coverage is overkill and that average crow-noms per harvest (of wheat, in my case --# of days of crow vulnerability would certainly affect this statistic) should be weighted against tillable tiles occupied by scarecrows.
Also, my experiences have led me to conclude that coffee (plural?) is money well spent on harvest days.