On one end, a farmer or agronomist who just uses a pen, paper, and some education and experience can manage a farm without any computer tooling at all - or even just forecasts the weather and chooses planting times based on the aches in their bones and a finger in the dirt. One who uses a spreadsheet or dedicated farming ERP as a tool can be a little more effective. With a lot of automation, that software tooling can allow them to manage many acres of farms more easily and potentially more accurately. But if you keep going, on the other end, there's just a human who knows nothing about the technicalities but owns enough stock in the enterprise to sit on the board and read quarterly earnings reports. They can do little more than say "Yes, let us keep going in this direction" or "I want to vote in someone else to be on the executive team". Right now, all such corporations have those operational decisions being made by humans, or at least outsourced to humans, but it looks increasingly like an LLM agent could do much of that. It might hallucinate something totally nonsensical and the owner would be left with a pile of debt, but it's hard to say that Seth as just a stockholder is, in any real sense, a farmer, even if his AI-based enterprise grows a lot of corn.
I think it would be unlikely but interesting if the AI decided that in furtherance of whatever its prompt and developing goals are to grow corn, it would branch out into something like real estate or manufacturing of agricultural equipment. Perhaps it would buy a business to manufacture high-tensile wire fence, with a side business of heavy-duty paperclips... and we all know where that would lead!
We don't yet have the legal frameworks to build an AI that owns itself (see also "the tree that owns itself" [1]), so for now there will be a human in the loop. Perhaps that human is intimately involved and micromanaging, merely a hands-off supervisor, or relegated to an ownership position with no real capacity to direct any actions. But I don't think that you can say that an owner who has not directed any actions beyond the initial prompt is really "doing the work".
[1]: https://en.wikipedia.org/wiki/Tree_That_Owns_Itself