[fennecfoxen]

Others pointed out the economies of scale in terms of production. I will point out that a large farming operation also has more resilience against risk. If some minor disaster takes out one of the fields on this farm, a blight on the one field, there are many other fields that may still be intact. This is even more so when you are Big Ag and you have multiple farms in different states. You might lose 5% of your crop to a bad hailstorm or an early frost in Oklahoma, but 95% of it is intact, while the small time Oklahoma farmer has no such consolation.

Agriculture isn’t just a numbers game for production, but also for spreading risk.

[bluGill]

Which is why historic small farms tended to be a lot of small fields. You didn't only only one patch of ground you had several. If the wheat field failed, maybe the barely elsewhere did okay and so you can at least survive until next year.