Much commercial soy is genetically modified (GM) to resist the active ingredient in Round Up. Commercial farmers just spray the entire plot with roundup, then when all the vegetation is dead, they plant their GM soy.
Cultivating is easy: just order a plane to spray roundup over your entire field. Everything dies except the soy. It's the most wide spread GM crop ever I think, though there are MANY vegetables that use genetically modified seed these days.
Perhaps it's possible that a GM crop can cause GM's in humans. It'll take a few generations to know for sure.
