I like to rise when the son he rises,
Quite late in the morning,
I like to shoot them small birds singing,
Merrily upon the set aside
And hurrah for the life of a country gent
And a tumble with the gamekeepers bride.

A colleague told me that a laylum is a sunken lane or track, with all pretty trees and stuff, but I aint too sure myself. Fallow land sounds plausible. As for not sure what you're singing about, try being a landlubber wot gets sea sick on the Woolwich ferry and warbling out shanties all night! Hoist yer clew garnets and stand by yer shank stoppers, all hands to the braces 'cos me pants are falling down!!!