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
snip
No, I
haven't checked the soil pH. Real men don't ask for directions, we wait
until we're out of gas ;O)
;O)

Jeff

Typically, conifer forests have low pH soils, I suspect that I am
confusing cause with effect.

I don't think it's clear cut.

Not much else grows in a pine forest, there is a lot of pine straw that
lingers until it burns. I think the overall environment shapes the soil
and it's pH, what little soil there is has poor construction. From what
I can tell deciduous leaves are more acidic than coniferous, it's as if
pine straw in the garden is completely different than pinestraw in the
forest.

http://forums2.gardenweb.com/forums/...944526608.html

All organic decomposition that takes place in soils (or compost bins) is
acidifying. That is, the decomposition process generates acid. If the
material being decomposed is full of bases, it is possible that the end
result is not acidic.

I am no pine needle expert, but I very seriously doubt that they are
full of bases. Coniferous trees tend to suck their nutrients back into
the tree before dropping old needles (unlike deciduous trees). Pine
needles are very different from oak leaves for this reason.

So given the fact that decomposing needles generates acid, and that pine
needles probably do not contain much in the way of bases, my guess would
be that yes, they will acidify the soil. Whether it will be enough of a
change to be noticeable is a different story. It would depend on the
buffering capacity (the ability to resist change) of the soil.



Also, it looks line pine forest have very high C/N ratios

http://www.fsl.orst.edu/~waring/Publ...orestEncyc.pdf
Leaf litter, wood, and root materials produced by evergreen
conifers usually contain twice the amount of carbon
(C) in relation to nitrogen found in corresponding materials
produced by deciduous angiosperms. As a result, the
decomposition of coniferous litter is usually 3*4 times
slower than hardwood litter, leading to a greater accumulation
of forest floor litter under conifers (Figure 1).
With time, as litter decays, soils under coniferous forests
maintain high C*N ratios and serve as storage sites for
amounts of carbon that far exceed above-ground biomass,
and have turnover times of centuries and millennia.


I think it's the lack of decomposition from too little green N, some
acid must then leach out, that is all there is as there is no buffer.

But, what do I know! Being wrong is more predictable than being right.


I have some monster azaleas growing under pines. I don't think this
is unusual, I'll have to test the soil some day. There's a foot or more
of pine straw in places.

Jeff

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

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.
--
- Billy
"Fascism should more properly be called corporatism because it is the
merger of state and corporate power." - Benito Mussolini.
http://www.youtube.com/watch?v=Arn3lF5XSUg
http://www.thirdworldtraveler.com/Zinn/HZinn_page.html