Is it an idiom or should it be understood literally?
It is from "The Sign and The Seal" by Graham Hancock. The full quote runs thus:
The peasant whom we met and talked to were poor, in some cases very poor indeed, and their lives were clearly ruled by the iron rods of soil and season.
"iron rods of soil" puzzles me the most. Unless it is an idiom, does it refer to some geological feature of the Ethiopian soil?
If it is an idiom, what is its meaning?