Oats are an important crop in the Upper Midwest, Canada, and northern Europe.
Oats are well-suited for marginal soils and cool, humid growing conditions. The crop has the second-highest water requirement among the major cereals, after rice. Oats were domesticated sometime during the first millennium B.C. from wild oats which were growing as weeds in fields of emmer and barley in the Near East. Thus, like rye, oat is a secondary crop . Oats became an important human food crop, however, only as they supplanted emmer in the cool climates of northern Europe to which Near Eastern peoples migrated.