On 28/07/2010 18:15, Chris Hogg wrote:
On Wed, 28 Jul 2010 00:17:53 -0700 (PDT),
wrote:

On 27 July, 20:39,
wrote:
What I've been told and as well reading all over the internet is that
vegetable plants grow best in soils of about PH6.5, slightly acidic.
Being slightly acidic allows the nutrients in the soil to feed up in to
the plant roots!

The PH of my soil was about PH9 when I measured it so I sprinkle sulphur
chips on it.

Why do you reckon that water at PH3 because of pine needles soaking in
it will not alter soil PH?

--
Vegegrower

You have hundreds of tons of topsoil in your garden. Why do you
think
sprinkling a couple of gallons of weak acid will make any difference?
It will react out instantly with the lime or chalk in your soil and
vanish utterly. Maybe a couple of milligrams of limestone will be
converted to CO2 and float away.
Your soil is slighly alkaline but good for every vegetable except
potatoes. It's specially good for brassicas. People spend a fortune
on lime to get soil like yours.
Of more importance is the soil structure. Now you can fix that. What
you need to set up is a compost heap. Nothing improves soil more
than
well rotted compost. Try to collect animal shit for your compost, this
rots down really fast. This also over the years will lower the pH.
I have huge native hedges. I cut once a year and shred all the twigs
& so have lots of compostable material.
The compost heap is the secret to good vegetable growing.

Good bit here about soils pH:
http://www.allotment.org.uk/fertilizer/garden-lime.php
http://www.allotment.org.uk/fertilizer/garden-lime.php


Harry is quite right. If your soil has that high a pH it must have a
very high chalk content (and I'm not sure it could actually be that
high even with pure chalk; I suspect your measurement system is not
wholly accurate). Chalk will maintain that pH value as long as it is
present in the soil. You would have to dissolve all the chalk away
before the pH started to drop, which would take many tons of the
organic acid present in pine needle rinsings (humic acid, fulvic acid
or whatever), let alone a few litres of solution at pH3, and would
mean you'd end up with a very big hole where your vegetable plot was,
even if it were possible.

The only way you might be able to do it would be by an industrial
process to put an inert insoluble layer onto every piece of chalk.

pH8 is about right for a damp chalk rich soil at STP. see for example:

http://en.wikipedia.org/wiki/Calcium...g_CO2_pressure

(table at the RHS grey line is atmospheric CO2 level)

I'm no vegetable grower, but AIUI brassicas are inclined to get
clubroot if the pH isn't high enough. Do as Harry says: pile on the
compost and pile on the manure and you'll grow great vegetables.
Forget the pH.

If you really want to grow blueberries or something else acid loving
then grow them in tubs or a raised bed. Most things will tolerate pH 8
without too much trouble concentrate your firepower on providing
conditions for the handful of acid loving plants you want to grow.

I'd suggest looking for interesting plants that grow on limestone
pavements and similar.

Regards,
Martin Brown