Billy wrote:
In article ,
Jeff Thies wrote:

Billy wrote:
In article ,
Jeff Thies wrote:

Billy wrote:
In article ,
Jeff Thies wrote:

Billy wrote:
In article ,
Bill who putters wrote:

In article ,
Jeff Thies wrote:

Billy wrote:
snip


Apparently, lots of rain will drive the pH of the soil down.


I'm struck by the pH world map. Little rain = Alkaline. It's almost a
map of the world's deserts. It's been an insight into how the globe
functions, I never thought SFG would take me there!

Jeff

Soils and acidity
Under conditions in which rainfall exceeds evapotranspiration (leaching)
during most of the year, the basic soil cations (Ca, Mg, K) are
gradually depleted and replaced with cations held in colloidal soil
reserves, leading to soil acidity. Clay soils often contain iron and
aluminium hydroxides, which affect the retention and availability of
fertilizer cations and anions in acidic soils.
Soil acidification may also occur by addition of hydrogen, due to
decomposition of organic matter, acid-forming fertilizers, and exchange
of basic cations for H+ by the roots. Soil acidity is reduced by
volatilization and denitrification of nitrogen. Under flooded
conditions, the soil pH value increases.
In addition, the following nitrate fertilizers -- calcium nitrate,
magnesium nitrate, potassium nitrate and sodium nitrate -- also increase
the soil pH value. Some alkaline soils have calcium in the form of
limestone that is not chemically available to plants. In this case
sulphuric acid
[edit]
Factors affecting soil pH
The pH value of a soil is influenced by the kinds of parent materials
from which the soil was formed. Soils developed from basic rocks
generally have higher pH values than those formed from acid rocks.
Rainfall also affects soil pH. Water passing through the soil leaches
basic nutrients such as calcium and magnesium from the soil. They are
replaced by acidic elements such as aluminium and iron. For this reason,
soils formed under high rainfall conditions are more acidic than those
formed under arid (dry) conditions.
Rainfall and acid affect the soil a lot.
[edit]
Soil life and pH
A pH level of around 6.3-6.8 is also the optimum range preferred by most
soil bacteria, although fungi, moulds, and anaerobic bacteria have a
broader tolerance and tend to multiply at lower pH values. Therefore,
more acidic soils tend to be susceptible to souring and putrefaction,
rather than undergoing the sweet decay processes associated with the
decay of organic matter, which immeasurably benefit the soil. These
processes also prefer near-neutral conditions.
http://en.wikipedia.org/wiki/Soil_pH#How_acidic_soil_forms

But all thing being equal, apparently conifers can change the pH as well.
http://www.sciencedirect.com/science...6T6X-3V8KST5-1
B&_user=10&_coverDate=12%2F28%2F1998&_rdoc=1&_fmt= high&_orig=search&_sort
=d&_docanchor=&view=c&_searchStrId=1346640603&_rer unOrigin=google&_acct=C
000050221&_version=1&_urlVersion=0&_userid=10&md5= 9063338fcb4564ecf07836d
69d60c9c1
http://soil.scijournals.org/cgi/content/abstract/54/5/1427

I was thinking that fungi modified the soil pH, but apparently they are
just opportunists who can thrive in low pH soil.

Anywho, it looks like a steady supply of pine boughs would lower the
soil pH. How many centuries that may take is another question.