Land and currency units in South Africa

[S. A. Modena]

I need to customize some software to Southern Africa...South Africa
and, I'm guessing, the associated independant states and nearby
countries.

I'm guessing that agricultural transaction are in Rand...what are the
recognized ways of abbreviating that?  (R 100, Rd. 100, ??)

Do farmer use strictly metric units for land area and yield values?
Or are there common local sub-hectare units in wide use?

Thanks,

Steve Modena    nmodena at unity.ncsu.edu