In The Foxfire Book there is a chapter on preserving vegetables. It mentions all the normal ways of preserving like, canning, pickling and drying. But it also has one more way I have never heard of.......Burying!
"To bury Cabbage, Dig a shallow circular trench on a gently sloped plot of ground. The diameter of the trench will depend on the number of cabbage you plan to preserve. Also dig a drainage ditch leading downhill ans way from the circular trench. This will serve to drain off any surface water that might accumulate and rot the cabbages. Throw dirt from the trench into the center of the circle, thus making a low mound. Cover the mound with straw. Pull up cabbages root and all. Place the cabbages on the mound so that the root of each is covered by the head of another. Then cover with straw and dirt. They will keep most of the winter."
To bury Potatoes, Dig a hole a foot or two below the frost line. Put in potatoes and cover with straw and pack dirt over that. Put a piece of tin on that. They will keep all winter."