I looked it up, too, in my old copy of Langenscheidt's German-English/English German dictionary.
I also have an old Langenscheidt from my school days! I didn't know they are also used "on the other side".
That's so cool
.
But what does it mean? To start the spring plowing? Or is it a poetic way of saying something else?
Yup, the farmer starts the spring plowing. No hidden meaning. The song goes on with details of what he, the wife and the maidservants are doing in spring, and concludes with an outlook to harvest time and the next winter.
It is a poetic respectively antiquated choice of words though. Märzen instead of März, and Ross/Rösslein instead of Pferd.