Well, the song's definitely not in Harland. Though he does note that there were enough street ballads about the famine 'to fill a volume', so maybe it's one of those. When I get the chance I'll go through the Harkness MSS here in the local library.

mg - for info on the famine itself, this is as good place to start as any. It was one of those events that seems to have been swept under the historical carpet - possibly because it 'only' affected a specific region of the country. However, we still remember.