Handling PostgreSQL serial field type in South
In PostgreSQL, serial type isn't actually a regular type.
What serial does is set an integer field up with the default value of the next number in a sequence. The sequence is stored elsewhere in the database (and can be manually created as well)
I've not tested this, but it would seem logical serial fields would all be represented as Integers in Django. Apply the default attribute to the Field and leave it off your inserts.
I hope that helps. :)