Scrub the beets, trim the ends, and grate. Chop or slice the turnips, potato, and carrots. Beets can be messy to prepare, so grate them last (and don't wear white!). In a large stockpot, saute the onion in margarine or butter for a few minutes, then add the caraway and the rest of the vegetables. Add the stock and the remaining ingredients. If you use fresh dill, add it at the end. Cover and simmer for 40 to 45 minutes, testing occasionally for doneness. Once cooked, you can puree this soup in a blender or food processor for a more delicate texture. Serve hot, garnished with a dollop of sour cream or a sprig of dill.