People who come to the US on H-1B visas aren't farmworkers. They're professionals with specialized knowledge. They have to have a bachelor's degree or higher; or the equivalent work experience to even qualify.
I've heard Donald Trump stupidly say he has lots of people working at his clubs that came here on H-1B visas; however, he's confused. Those would be H-2B visas. He doesn't even know the difference and he's the one who will be making decisions about this stuff? Man oh man, gonna be a long four years.