As it commonly applies to raising plants, "cultivation" usually refers to a process involving the manipulation of soil, to incorporate plant residues into the soil after the previous harvest, to prepare a seedbed for new planting, or between the rows of a growing crop to suppress weeds. That aspect, the manipulation of soil, isn't particularly emphasized, it's just assumed, like breathing; it's seen as being inextricably part of the process, not every time the farmer enters a field, but sooner or later, and repeatedly. "Tillage" is a synonym for this sense of the word.
There's a more general sense of "cultivation" that simply refers to raising plants, and which applies as much to the practices of nomadic tribes, involving no more tillage than poking seed holes in the ground with a sharp stick, as it does to agriculture as it is commonly practiced today.
It's that second, more general sense of the word that's intended here, as the potential advantages of using robotics in horticulture and agriculture stem largely from making it possible to dispense with the other sense of the word, tillage.
That's not to say that a cultibot wouldn't perform soil manipulation, rather what's expected is that it will resemble what a gardener performs with a hoe, trowel, and (occasionally) shovel, instead of what a farmer performs with a plow, and that the total amount of energy involved in performing it will be a small fraction of what the current practice of farming consumes -- and the rate of energy consumption even lower, since autonomous operation will allow it to be distributed over more time, perhaps even 24/7. (This combination of lower energy requirements and more time should make solar panels a practical power source.)
There's yet another sense of the word, as it applies reflexively or to human relationships, as in the cultivation of patience or friendship, which should at least inform how the vision of cultibotics is understood. In its fully realized state, a cultibot would not only raise plants and produce food, but it would tend the land in all its aspects, specifically including as it also serves as habitat for wild species, both plants and animals. This could be seen as cultivating a field's participation in the larger environment, making a little room among the crops for other life.