You can grow emeralds using AgriCraft Emeryllis crops
Agricraft Resource Crops are disabled by default in Infinity Evolved (non-skyblock).
Melting Villagers does work, as far as I know. You may be better off just trading for your Emeralds. A small wheat farm is usually good for a dozen blocks of Emeralds if you seek out the right trades.
Teach a man to melt villagers, he'll have a few Emeralds. Teach a man to trade, he'll be able to swim in them.