Differences: 建地, 農地 and 旱地

Does anyone know the differences, particularly as they relate to what can be built on the different types of land? For the last one (旱地), I’m not sure I got the character right but it’s what came up on a search.
To give an idea of what I’m looking for, I know that for farmland (農地), you can build on 1/10th of the land. There’s also a minimum amount of land that you must buy (I’ve heard 880 ping from one person who seemed to know what she was talking about).

yes, they are different, the place where you can build a house which is most expensive, a place where for farming, you usually can not build the house (unless the land is big enough, about 756 ping, a place where is lack of water, usually no one wants it.

you might want to check your local land office, i think it may differ between counties. also note that although most people use ping for small lots and fen for larger ones, the government titles actually use square meters. Despite most realtors being shit at their job and knowing next to nothing, tell them to give you exact number in meters squared for anything truly reliable. it will be written on the title, they just have to go check.