Forces of Change

In Ancient Mesopotamia

Organized farming fed the first cities 4,000 years ago.

The Tigris and Euphrates rivers made it possible to grow wheat on the arid Mesopotamian plains, but the dry climate eventually defeated human engineering. Irrigation brought water to fields faster than it could drain out. As salt-rich groundwater rose and surface water evaporated, mineral salts built up in the soils. Farmers switched to more salt-tolerant grains like barley, but the harder they farmed, the less they harvested. After about 2,000 years, the once-fertile land of southern Mesopotamia was barren.

Spiral minaret of the Great Mosque
The mud brick spiral minaret of the Great Mosque, Samarra, Iraq, a.d. 847–861
Courtesy Alastair Northedge
Sumerian cuneiform tablet
Sumerian cuneiform tablet, listing herders and cows in the goddess Inana’s fields, 21st–20th century B.C., replica
Reproduction provided by University of Pennsylvania Museum of Archaeology and Anthropology