I would be cautious about growing in corn fields.... cops are notorious for using choppers to search them for marijuana. Think about how easy it is to spot something that looks out of place in a giant uniform field - especially if you have to clear a sizable area for it. You get a couple of trained cops up there and they will be able to pick it out for sure and compromise your grow. Sure people do it, and maybe some don't get caught, but it doesn't make it any less risky. Unless you live in an area where they seldom look then I hope you carefully consider your options. Your judgement call though obviously since you know the place better, but just figured I'd give you a heads up for potential trouble.