Well their could be unbreakable enchantment for hoes and also some sort of loot for it to the loot enchant could make it so you get more everytime you break some plant with it
Interesting idea, but, I cant say I will earn 50 levels of experience just to enchant a hoe that tills soil and breaks plants I would rather use the 50 levels on a diamond pick, armour our sword *Edit* This was my 1000 message, feel special I chose to post it here