Experimenting is the key.
As I have only used this technique on my pickup I am not sure the best method for a tractor. If you wanna give it a try you could also try wrapping different materials around the length of the rope to see how it helps. For example try using tie wire, as I am sure it will not be to harsh on the concrete but it will probably not last long either. My main concern w/ wrapping things around the tire of my pickup is what possible damage can it do at highway speeds? As this is not much of a concern on your tractor(especally if your keeping it in low) there are all sorts of possibilities. Wire rope for example is not so harsh and will probably last a long time and still get great traction. You just gotta try all possibilities that present themselves to you. If you have an idea think through the possible benefits vs. the worst case scenerio and weight your decision accordingly.
As far as using the synthetic rope you will need to wrap something around your knots(at least this is what I have found at higher speeds)as they are very prone to unknotting.
Other than that good luck if you have some other material available or any other ideas of things to use run it by everyone here and we can all help to think of possible scenarios that may give cause to use or not to use it.
Good luck