CR Archive | Re: Archaeologist: For 2,000 years the ancient Sumerians depended on

Archaeologist: For 2,000 years the ancient Sumerians depended on irrigation to sustain the agiiculture that fed their civilization. But eventually irrigation built up in the soil toxic levels of the salts and other impurities left behind when water evaporates. When its soil became unable to support agiiculture, Sumerian civilization collapsed. A similar fate is thus likely to befall modem civilizations that continue to rely heavily on irrigation for agriculture.

Which one of the following, if