section_path: History/Fall and transmission
section_name: Fall and transmission
paragraph_text: Fall and transmission
  
  This period is generally taken to coincide with a major shift in population from southern Mesopotamia toward the north. Ecologically, the agricultural productivity of the Sumerian lands was being compromised as a result of rising salinity. Soil salinity in this region had been long recognized as a major problem. Poorly drained irrigated soils, in an arid climate with high levels of evaporation, led to the buildup of dissolved salts in the soil, eventually reducing agricultural yields severely.
  
  During the Akkadian and Ur III phases, there was a shift from the cultivation of wheat to the more salt-tolerant barley, but this was insufficient, and during the period from 2100 BC to 1700 BC, it is estimated that the population in this area declined by nearly three-fifths. This greatly upset the balance of power within the region, weakening the areas where Sumerian was spoken, and comparatively strengthening those where Akkadian was the major language. Henceforth, Sumerian remained only a literary and liturgical language, similar to the position occupied by Latin in medieval Europe.
  
  Following an Elamite invasion and sack of Ur during the rule of Ibbi-Sin (c. 2028–2004 BC), Sumer came under Amorite rule (taken to introduce the Middle Bronze Age). The independent Amorite states of the 20th to 18th centuries are summarized as the " Dynasty of Isin " in the Sumerian king list, ending with the rise of Babylonia under Hammurabi c. 1800 BC.
  
  Later rulers who dominated Assyria and Babylonia occasionally assumed the old Sargonic title "King of Sumer and Akkad", such as Tukulti-Ninurta I of Assyria after c. 1225 BC.