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What I don't understand is how Sörgel claimed that this plan would create more farmland. Wouldn't any land exposed by drops in sea level be irredeemably contami

What I don't understand is how Sörgel claimed that this plan would create more farmland. Wouldn't any land exposed by drops in sea level be irredeemably contaminated by salt, just like land being inundated by rising sea levels?

arethuza 10y ago
A fair bit of land in areas that was heavily glaciated was formerly below sea level and has been raised by post-glacial isostatic rebound - a lot of this is farmed so I don't think there is a fundamental problem.
- 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."
vilhelm_s 10y ago
In the Netherlands they farm on reclaimed land without any problems.
lyle_nel 10y ago
This seems relevant to your questions. Among other things, it discusses which crops are best suited for salinated soil as well as improving conditions for crops in salinated soil using potasium fertilisers. Also relevant to your question, it discusses desalination strategies. http://www.fao.org/docrep/x5871e/x5871e04.htm http://www.fao.org/docrep/x5871e/x5871e04.htm

arethuza 10y ago

A fair bit of land in areas that was heavily glaciated was formerly below sea level and has been raised by post-glacial isostatic rebound - a lot of this is farmed so I don't think there is a fundamental problem.

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."

vilhelm_s 10y ago

In the Netherlands they farm on reclaimed land without any problems.

lyle_nel 10y ago

This seems relevant to your questions. Among other things, it discusses which crops are best suited for salinated soil as well as improving conditions for crops in salinated soil using potasium fertilisers. Also relevant to your question, it discusses desalination strategies. http://www.fao.org/docrep/x5871e/x5871e04.htm http://www.fao.org/docrep/x5871e/x5871e04.htm