> I thought OP was talking about row crops which can't feasibly be irrigated with hoses.
Are we talking about irrigation pivots[1] here? Because those are a known technology.
If we are thinking about robots driving up and down the rows and watering plants from a tank, and then returning to some central location to re-fill their tank that feels like a "carrying water for elephants" situation. I suspect the logistics won't work out. Could try to run some numbers on it of course. Is that how you are thinking about it?