You can do it. Rototillers like to operate at slow speeds like 0.5 mph. You can run your 135 in low range 1st gear at reduced engine rpm (1300-1500 rpm) to slow down your ground speed and give the rototiller a chance to do its thing. You'd need a rototiller at least 6 feet wide to cover the wheel tracks--no problem for the 135's pto or 3pt hitch, but the cost may be more than you want to spend on a rototiller.