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[EarthNSky <erthnsky AT bellsouth.net>]

Bill Jones wrote:

> >
> I think this is just an error in logic.  Leaching eventually causes 
> acidity, but the lack of it does not necessarily cause alkalinity. 
> You can readily observe in a limestone cavern how the ground water 
> has been leaching calcium from the surface and redepositing it deep 
> underground.

That's not exactly correct.
Rainwater absorbs carbon dioxide, forming carbonic acid, from the
atmosphere and as it flows underground it reacts chemically with certain
rocks like limestone.  Limestone, calcium carbonate, is already in the
ground(it's sedimentary rock), it doesn't leach from the surface, i.e.
the calcium is not redeposited. The acidified rainwater reacts with the
limestone and erodes a space, forming a limestone cavern.


> The sources of stable alkalinity as the column I and II metals: 
> sodium, potassium, calcium, and magnesium.  For instance, many areas 
> in Europe have a thick layer of limestone from ancient deposits of 
> seashells. The volcanic regions that you and I live in don't have 
> that.  Unfortunately that's why our area isn't going to become the 
> next France, agriculturally.  So that's a second way that a soil 
> becomes acidic, simply by being born without any of these metals to 
> start with.

Acidic soils in the east are a result of eroded granite mostly, and
since the landforms in the west are geologically younger, there simply
hasn't been a long enough time for widespread acid regions of soil.
France, I believe, has acidic soil from underlying granite.
Limestone, as you mentioned, is sedimentary and formed from deposits of
seashells, coral, etc....ancient seas and oceans kind of thing.

There are plenty of places out west, however, where the soil is acidic,
but from different processes. A couple of hours on the USGS site should
illuminate the history of your area and give you an idea of what lies
beneath your feet.  It may not be necessary to do a lot of testing when
you can read the geological history of your area and take advantage of
the experiments of others who came before you, native or modern.  No one
spot on earth is best to grow everything, but perhaps you can amend a
small area of your plot to gain some diversity in what you can plant.

As an aside, if you live in a region where the soils are really
alkaline, the easiest, long term way to amend the soil is to plant
evergreen trees, especially pines and maybe certain oaks, dependent on
your zone.

Bev



--
Bevanron of EarthNSky Farm   Sleep well tonight, for somewhere in the
ocean's depths, MY son is protecting YOUR freedom.