Interesting, so how does the winch system work is it actually pulled and released from each pole base? Are they going to be modularized so they can pass tools along multiple such systems? Have you thought about harvesting and collecting?
I use a winch based on a stepper motor. Everything is modular so that it is easy to make a robot with just 3 wires or with 8 for 6 DOF experiments.
Passing tools among a neighboring system is going to be hard as there is a "dead zone" bordering the rectangle drawn by the pole but there may be a way to smartly cross the wires so that two system may share an area where they could pass around tools.
Harvesting is actually, counter-intuitively, a low priority task IMO. This is usually a single day of work, and this is the one with the highest stake, where things going wrong can jeopardize your whole harvest. People will want to be present for it I think.
What needs to be automated first are the tedious tasks that need to be done repeatedly : weeding, monitoring, watering.
About harvesting, a farmer friend proposed something interesting: just pass bags/baskets from the field's side to the place when the human is inside the field. Ricefields are very muddy and if you work in the middle of one, doing back and forth to the border is really tedious.
Do you have any contact info?