When ancient Rome was young

A multi-faceted remembrance of Rome: 

In her early days Italy was famous for her wheat, which provided not only her own population but also that of Greece. The fertility of Italian soil was probably the reason for the establishment of Greek colonies in southern Italy. The importation of Italian wheat into Greece in Sophocles's time is still famous. But in Cato's time Italy was already dependent upon Sicily, which Rome's great old man called the provider for the Roman people. In all probability this dependence upon Sicily as its granary was the paramount reason for Rome's conflict with Carthage. Province after province was turned by Rome into a desert, for Rome's exactions naturally compelled greater exploitation of the conquered soil and its more rapid exhaustion.

From "Rome's Fall Reconsidered" by Vladimir Simkhovitch (page 223).

Dates:

Greek colonies established in Italy: from the 8th to 5th centuries BC. Italy was fertile then.

Sophocles's time: 496-406 BC, or almost all of the fifth century BC. Sophocles was born just at the end of the Greek colonization of Italy. And 496 BC is, what, 13 years after the Roman Republic was established in 509 BC on the entrails of the Roman Kingdom.

Cato's [the elder] time: 234-149 BC. Suppose we count from 200 BC and say Cato had 50 years, the whole first half of the second century BC, to be Rome's "great old man". 

Greece colonized various fertile areas of Italy between 800 and 500 BC. And Italy was still considered fertile in Sophocles's time, that is, for the next hundred years after 500 BC. But then, three hundred years later, around 200 BC (in Cato's time) fertility on the Italian peninsula was wearing thin.

 

I'm still thinking about how Simkhovitch's exhaustion-of-the-soil argument stands up to Ellsworth Huntington's climate-change argument.