AdvertisementOpinionA Growing Debate: How To Define 'Organic' FoodMarch 01, 2011Dan CharlesfacebookEmailCows graze at a Horizon Organic farm in eastern Maryland. Even though the milk produced here is deemed organic, a very small percentage of corn used to feed the animals may contain genetically modified material because of unavoidable cross-pollination between genetically modified corn and the organic variety. (Horizon)