Emilio Camacho and Jennifer Caruso could hardly be more different. He's a migrant worker from El Paso, Texas. She's a home-schooling mother from Hightstown. What they have in common is Honey Brook Organic Farm in Mercer County, the nation's largest practitioner of an increasingly popular business model called community-supported agriculture. Camacho and his family are the field crew, the backbone of the 60-acre farm. During the growing season they till the fields and pull the weeds, commuting from a rented house in Trenton. Caruso and 2,986 other New Jersey and Pennsylvania residents are the farm's members. Their checks fill its...