We'll be staying in Bologna this March and are planning some daytrips outside the city. We've already decided on Ravenna but were wondering if a second trip should be to Parma or Ferrara. Any thoughts?

I can't speak about Parma, but Ferrara is an excellent daytrip choice. I can also recommend an excellent restaurant there--Il Bagattino Trattoria on Via Correggiani 6.

I too loved Ferrara. And Ravenna is fantastic. Have not been to Parma however so can't really say whether or not it is better than Ferrara. Don't think you could miss with either.
You will have a beautiful trip!

We haven't been to Ferrara but I enthusiastically recommend Parma. We spent two days there and would gladly return. If it's cold in March there are interesting indoor activities in Parma: wonderful baptistry, numerous churches and museums and, of course, prosciutto di Parma, Parmesan drizzled with aged balsamic vinegar, and many other treats... Enjoy your stay in Bologna!

I haven't been to Parma, but spent one day/night in Ferrara. Wonderful, intersesting town. Be sure sure to see the Este Castle, surounded by a working moat and do not miss the Palace of Diamonds, which houses the National Picture Gallery. Check out what special exhibits are there at the time of your visit. We were lucky enough to hit a John Singer Sargent exhibit, exclusively his work in Italy. We stayed at the Ripagrande hotel. Very reasonable,(150 Euro) for a three story suite! I can't remember the name of the restaurant we dined at, but it was directly across the street from the hotel and fabulous.