agricultural achievements
Farming of oceans is called just that. It is usually referred to as ocean fish farming as well.
Crops what else
Monoculture means growing only one type of crop, such as, for example, planting only corn and nothing else.
a Spanish farming village was called a Royal Road village...
A farming degree is a degree in agriculture.
Farming land that was owned by someone else.
A method called slash and burn was used where they clear the land by burning it down and when it was no longer fertile they would move somewhere else and allow the land to grow back.
Large, self-sufficient farming estates were called Manors!
Farming that provides only enough food for the farmer and his family and none for market is called subsistence farming.
I would say the person who improved farming more than anyone else was George Washington Carver.
Arable
Agriculture.