That’s a failure of imagination. Hordes of people used to do all the work, and Industrial Age engineering (thinking) replaced them with a combination of large, specialized devices and large, specialized farm layouts. It was more efficient for the technology of the time.

But we don’t build computing like that any more. Instead of large centralized single devices we use a large amount of protean hardware with various adapts (software).

Hordes of small devices can flood through the fields, using sensors to decide at any point what to do, and can use different effectors for different tasks at different times of the year, like the humans used to do.