I had a friend with a salatin style tractor who tried it but the wood wasn't strong enough and after a week or so started to come loose.

For my backyard tractor I just put a couple of fence pickets underneath and used them like ski's. It also had the benefit of keeping anything from reaching under the tractor to grab a midnight snack.

You can use a dolly/handtruck with inflatable wheels if you have somewhat uneven terrain.