Regardless of the legal designation, it refers to paddy fields and fields including the dry riverbeds, cultivated land, reclaimed land, etc.
Commentary
Paddy fields refer to arable lands that use water to grow crops such as paddy rice, water parsley, lotus root, etc. Fields refer to arable lands other than paddy fields. Fields also include orchards.
Source
KOSTAT (Census on Agriculture, Forestry and Fisheries and other)