I work on a small college campus with about 3 acres of irrigated lawn, 5 acres of athletic fields, and 15 acres of unirriagated campus/property. When I arrived 3 years ago, we were using a Craftsman pull behind aerator that you can place weights on top of. Our soil has an extremely high clay content and it is near impossible to get any decent plugs with that small implement. We had an out of commission riding Ryan Lawnaire with an 18" swath that was pulling half inch cores spaced like 2" apart. We fixed it up and I maybe plugged half an acre when an internal drive rod for the tines broke. I'd have to completely dismantle the machine to get in there and weld it/beef it up and even then it is still a fairly small unit for as much ground as I have to cover. (I'm the only employee) I currently have a pull behind unit for a large tractor I use on the athletic fields that I love, but it would never work on campus. I have a lot of sidewalks, buildings, and trees to maneuver around and really probably need something 36"-48". I've looked around, but haven't really been able to find something suitable. Anyone have any suggestions for something walk behind, ride on, or perhaps a pull behind for a mower that would be sturdy enough to give me 2"-3" deep cores in this heavy clay soil and be fairly manueverable? I think I'd really like it if I could get my hands on a smaller tractor that I could hook up a small 3-point unit to, but at this point I'm open to suggestions. Thanks!