The Degradation of Irrigated Soils Across the Once Very Productive

Multiple Choice

The degradation of irrigated soils across the once very productive "Fertile Crescent" of the Middle East was due primarily to _____.

A) high calcium and magnesium levels in the irrigation waters
B) high levels of calcium-containing salt in the irrigation water
C) inadequate equipment and power to properly cultivate the soil
D) poor internal drainage of the soils
E) destructive wars in the region