The Midwest has a rich agricultural industry due to its flat topography and humus-rich soil deposits which have made it the nation's breadbasket, producing grains like corn, soybeans, and wheat. Invention of machinery like the grain combine led to larger industrial farms and the decline of small farms, pushing many residents to cities. Major industries in the Midwest include steel production in Great Lakes cities, auto manufacturing centered in Detroit using iron ore from the region, and agriculture which dominates both landscapes and economies across the region.