4 ms·

I think the problem is getting enough rainfall to rinse salt from the topsoil. I don't know how much is needed. Parts of Sweden were in the Baltic during Vikin

by dalke 10y ago

I think the problem is getting enough rainfall to rinse salt from the topsoil. I don't know how much is needed. Parts of Sweden were in the Baltic during Viking times but are now farmland, so perhaps no more than a few hundred years? Then again, there's more rain in those areas of northern America and Europe where the glaciers were than in the Mediterranean.

JoeAltmaier 10y ago
I think a very long time indeed. The classic way to render fields unfit for generations is to salt them.
- dalke 10y ago
  I wondered how long it took for the fields of Carthage to be fertile again. If my supposition is correct, it should need only a few years for normal rain to carry it away, not generations. I found https://en.wikipedia.org/wiki/Salting_the_earth https://en.wikipedia.org/wiki/Salting_the_earth which suggests that the salting was more symbolic, or a curse, and that "There is no evidence that sufficient amounts of salt were used to render large tracts of land unusable." Given how expensive salt was, it seems like it would be horrendously expensive to do that in the classical era.
  - JoeAltmaier 10y ago
    And yet the Central Valley of California has square miles of dead land, due to selenium salts(?) that build up. They don't go away. They creep to the surface and appear as a crusty deposit. Salt is weird, and irrigation water evaporates it doesn't 'wash away' anything.
    - dalke 10y ago
      Portions of the Central Valley do not flow to the sea. Salt stays in a basin. To note, we were discussing land which emerged from the sea due to post-glacial rebound, or where the sea was lowered through engineering effect, not basins. Nor is Carthage in a basin. Agricultural water runoff is a thing. The water doesn't all evaporate. Quoting http://www.watereducation.org/post/salinity-central-valley-critical-problem http://www.watereducation.org/post/salinity-central-valley-c... , "Every time a farmer irrigates a crop, salt ends up concentrating in the runoff and groundwater."

by dalke 10y ago

JoeAltmaier 10y ago

I think a very long time indeed. The classic way to render fields unfit for generations is to salt them.

dalke 10y ago
I wondered how long it took for the fields of Carthage to be fertile again. If my supposition is correct, it should need only a few years for normal rain to carry it away, not generations. I found https://en.wikipedia.org/wiki/Salting_the_earth https://en.wikipedia.org/wiki/Salting_the_earth which suggests that the salting was more symbolic, or a curse, and that "There is no evidence that sufficient amounts of salt were used to render large tracts of land unusable." Given how expensive salt was, it seems like it would be horrendously expensive to do that in the classical era.
- JoeAltmaier 10y ago
  And yet the Central Valley of California has square miles of dead land, due to selenium salts(?) that build up. They don't go away. They creep to the surface and appear as a crusty deposit. Salt is weird, and irrigation water evaporates it doesn't 'wash away' anything.
  - dalke 10y ago
    Portions of the Central Valley do not flow to the sea. Salt stays in a basin. To note, we were discussing land which emerged from the sea due to post-glacial rebound, or where the sea was lowered through engineering effect, not basins. Nor is Carthage in a basin. Agricultural water runoff is a thing. The water doesn't all evaporate. Quoting http://www.watereducation.org/post/salinity-central-valley-critical-problem http://www.watereducation.org/post/salinity-central-valley-c... , "Every time a farmer irrigates a crop, salt ends up concentrating in the runoff and groundwater."