Any field or farm parcel from which harvested crops are intended to be sold, labeled, or represented as ``organic,'' must:
(a) Have been managed in accordance with the provisions of Secs. 205.203 through 205.206;
(b) Have had no prohibited substances, as listed in Sec. 205.105, applied to it for a period of 3 years immediately preceding harvest of the crop; and
(c) Have distinct, defined boundaries and buffer zones such as runoff diversions to prevent the unintended application of a prohibited substance to the crop or contact with a prohibited substance applied to adjoining land that is not under organic management.