Corn producers can reduce the chance of cross-contamination via pollen drift by separating fields by at least 150 feet (46 m); however, many identity preserved corn programs require that non-GMO fields be separated from GMO corn by a distance of at least 660 feet (200 m).[2] They may also utilize a technique called 'flooding' by surrounding their fields with a border of non-GMO corn, the theory being that these 'border rows' of corn will dilute any outside pollen, thus reducing the risk of cross-contamination. Producers can also alternate planting dates to prevent crops from releasing their pollen at similar times.[2][3]