"The majority of the nation’s 2.1 million farms are small in terms of sales; 75 percent sold less than $50,000 in agricultural products in 2012 and 57 percent had sales less than $10,000. The farm is the place of residence for three fourths of principal operators, but it does not provide the majority of their household income. For 1.5 million farm households, less than 25 percent of household income came from their farm. In 2012, 61 percent worked off the farm at least some days, and 40 percent worked off the farm for 200 or more days."
That doesn't sound like big corp to me, and it most seem to be working a couple of jobs
https://www.nass.usda.gov/Publications/Highlights/2014/Farm_Demographics/index.php