The payday’s a-coming for the Campbell family farm.That’s what I keep telling my wife, Debbie, and I can tell she believes me by her crunch-eyed grin that follows. Sometimes she starts outright laughing, which I take as part of her good nature.We’re growing corn and happiness. Not that there hasn’t been setbacks in the past year since I bought a four-row corn planter, vintage 1970s. As I look…