The thread below reminded me of the work of W.C. Lowdermilk that I read in High School.  I obtained a copy through the ASCS office (now NRCS) and highly recommend reading it whether you doubt soil health and civilization are connected or not.

You can read Lowdermilk's presentation here:
 http://www.soilandhealth.org/01aglibrary/010119lowdermilk.usda/cls.html

Or download it as a pdf here:
http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1043789.pdf

As it so happened I was reading to my daughter from a storybook bible earlier tonight and read several short stories from the time of Joshua and Jerrico to the time of the fall of Jerusalem and their enslavement at the hands of King Nebuchadnezzar of Babylon.
Even though the stories were shortened, having them fresh in my mind made reading Lowdermilk's work even more interesting.