Those are largely mega-farms run similar to mega-corporations, and they utilize a lot of immigrant labor. There are a few independent farmers around eeking out a living, but not many.
Capitalism generally favors mega-farms though, due to the efficiencies of scale.
Larger corporations can more reliably offer wages, better plan for trends, better analyze market conditions, afford the latest technologies, etc. etc.
Traditionally, when companies got too big in the USA, the regulators would split them up to allow competitors to flourish. This sort of splitting doesn't happen these days however.
>This sort of splitting doesn't happen these days however.
They sure haven't. Last real breakup was AT&T in the early 1980s? I think that's my biggest gripe with politics today. Neither party is willing to break up these big companies and often gives the green-light for mega mergers without much fuss.