I'm not sure what you mean by "marching songs", but I wonder if songs you'll find by typing @chaingang in the search box (above right) will suit?
"Die Moorsoldaten" (the peat bog soldiers) could be what you're looking for. I don't see it in the database, so I'll search my memory (the English translation):

Far and wide as the eye can wander,
Peat and bog are everywhere
Not a voice sings out to cheer us
Oaks are standing gaunt and bare

[refrain]Wir sind die moorsoldaten
Siehen mit dem spaten
Ins moor[We are the peatbog soldiers
marching with our spades
to the bog

Up and down the guards are pacing
No one, no one can get through
Flight would mean a sure death facing
Guns and barbed wire
haunt[?]our view

But for us there is no complaining
Winter will in time be past
One day we shall cry, rejoicing:
!"Homeland dear, you're mine at last!"
No more will the peat bog soldiers
March with their spades
to the bog