Lt. Robert Kirk of the Van Buren County Sheriff's Department said the family called shortly after 10 p.m. Wednesday to report the discovery.
Kirk said it appeared that someone pulled out a row of corn and planted the marijuana, knowing that the farmer's field would be fertilized and watered. In cases like this, Kirk said whoever planted the marijuana would usually come back before the corn was harvested.
Authorities said it's common for marijuana growers to try to hide plants in farmers' fields this way.
Sheriff's deputies pulled up the marijuana plants and they will be destroyed.