Hi Brushmaster,
I have a 2920 with Turf tires and was also concerned about blading with no chains. Still I decided to go it without chains and if I learned that I needed them, I could always buy them later. Here in Southern Maryland we got slammed about 3 weeks ago with 20 inches of snowfall. I went out and bladed and never had much of a issue. I have a 1/3rd mile long drive with some fairly steep hills.
I talked to my Kubota sales rep afterwards. "How'd you do?" he asked. I told him "great", and his response was "Yah, that's what I thought, I think I've only sold one set of chains in the last 5 years for B series with turf tires".
Do a search and you should see some additional posts on this subject.