"The main stream [Euphrates-grm] then follows a winding course southward
crossing from Turkey into Syria near the ancient city of Carchemish and so
eventually into Iraq. At this point it is separated from the Tigris by
some 250 miles of steppe country and the two do not draw together again
until reaching the neighbourhood of Baghdad and Ramadi. Here the Euphrates
is flowing at a level 9 m higher than the Tigris, and a sequence of ancient
irrigation canals, draining from one river into the other, in earlier days
made the belt of country between them extremely fertile. Beyond this,
their streams separate again, and the plain is served by a more complicated
system of canals and diversions." ~ Seton Lloyd, The Archaeology of
Mesopotamia, (New York: Thames and Hudson, 1978), p. 16
"Next to the effects of flooding, the most disastrous danger to
Mesopotamian agriculture generally has been the salinization of the soil
and the consequent practice of what is known as 'extensive cultivation'.
Traveling in Iraq today, one cannot fail to see the results of the
mishandling of the soil. Wide areas, no longer cultivated, are covered
with a white incrustation caused by overprolonged cultivation. The water
comes from the river with a strong saline content and, as it evaporates in
the hot sun, the salt is deposited, ruining the fertility of the soil.
When this happens to land in an 'extensive economy', the farmer simply
transfers his cultivation to new ground and starts irrigating all over
again. But an even more serious source of salinization is the rise in
level of ground-water as a result of prolonged irrigation, which pushes the
salt up to the surface. Only efficient drainage can coutneract this effect;
but there is no inducement to go to such lengths as long as 'extensive'
agriculture can be practised.
"In the late 1950s much new light was thrown on this subject during the
course of a study by Thorkild Jacobsen, one of the great Assyriologists of
our time. In a variety of cuneiform texts, he found unmistakeable
references to the results of salinization, and could study its effects over
a long period of history. jacobsen was able for instance to gather that
soil deterioration was particularly serious in the city state of Lagash,
where salinization began in about 2400 BC and spread westward towards the
Euphrates. A thousand years later, it had reached as far as Babylonia. He
was able to calculate that wheat at first accounted for 16% of the total
crop. Three centuries later, the percentage had dropped to 2% and, between
2000 and 1700 BC his reports contained no mentions of wheat at all. Even
the barley, whose greater toleration of salinization had long made it the
principal crop, could now be seen to have a gratly reduced yield per acre
in many southern districts. Information of this sort gave substance to a
picture of diminishing agricultural prosperity, moving continually
northward as a result of soil impoverishment in the south. This, he
thought, could even account fo rthe sequence of major changes in
Mesopotamian history, by which political ascendancy transferred itself
first from Sumer to Babylonia and later to the Assyrian kingdom in the
north, where the problem of salinization did not arise. Nevertheless,
there is much evidence to suggest that the dimunuition of agricultural
productivity during these centuries was only a temporary affair. For
jacobsen and his colleagues, examining the Diyala area east of Baghdad,
were able to detect already in the late 3rd millennium BC improved
techniques for combating salinization, or at least delaying it. Long
experience had resulted in the contrivance of better practices for
extracting a maximum yield from the soil. A Sumerian agricultural manual
of about 2100 ABC even suggested the use of a primitive fallow system and
elementary forms of drainage." ~ Seton Lloyd, The Archaeology of
Mesopotamia, (New York: Thames and Hudson, 1978), p. 17-18
glenn
Adam, Apes and Anthropology
Foundation, Fall and Flood
& lots of creation/evolution information
http://www.isource.net/~grmorton/dmd.htm