The other day i was think about a wench tractor just for light plowing. Not sure just yet what it would look like. Maybe a go cart frame or broken lawn tractor with small steel plows under it and wench on the front. I guess i would have to hook it to a tree.
I hope this doesn't seem like I'm picking nits: you mean "winch." I wouldn't mention it, except that "wench" might be offensive.
There's a long history of similar designs, called "ploughing engines". I think the people using those worked out that, once the engine became lightweight enough to bring through the fields, and once treads had been developed, it wasn't often worth dealing with so much cable.
"the qualities of these bacteria, like the heat of the sun, electricity, or the qualities of metals, are part of the storehouse of knowledge of all men. They are manifestations of the laws of nature, free to all men and reserved exclusively to none." SCOTUS, Funk Bros. Seed Co. v. Kale Inoculant Co.
When I saw the topic, I thought maybe you were going to have some poor young girl pull your plow (I hope not a wife!). But I realize you are probably talking about what I would call a winch. It is true this would get around the problem of carrying lots of weight for the traction to do it the normal way. But the power needed would be the same for the same speed of movement in any case.
That being the case.... and steering not being needed. It may be a great application for a solar power unit. Your tractor (winch platform would be a better term) could move as slow as needed to match the available solar power (gearing will fix lots). You could do other things while it works and a bump (not a knot) in your winch line could switch it off at the end of the field while sounding a horn for a moment to alert you it was done.
Anchoring could be a tree, but may result in a dead tree or pie shaped plow area with parts nearest the tree getting plowed more than once. If you had to plant one just for this use there is also the time for it to grow. poplar grows fast if you can plant it far enough from any buildings and you could coppice it above your anchor point for firewood too. This would result in a good strong root system, a large trunk where you need it, not too large of a tree to shade everything or drop lots of fluff/seedpods.
Just so you know, here it is right from the dictionary: wench (wnch) n. 1. A young woman or girl, especially a peasant girl. 2. A woman servant. 3. A wanton woman.
winch (wnch) n. 1. A stationary motor-driven or hand-powered machine used for hoisting or hauling, having a drum around which is wound a rope or chain attached to the load being moved. 2. The crank used to give motion to a grindstone or similar device.