Trees in pots
 

"Rodger Whitlock" wrote in
message ...
On 19 Nov 2002 20:36:25 GMT, (DaveDay34) wrote:

it? Osmosis will operate until all the soil is truly saturated.

Osmosis doesn't operate until all the soil is saturated.

You are both confusing osmosis with capillarity.
It's capillary attraction that causes a pot standing in 1/2" of
water to become waterlogged, not osmosis.
Rodger Whitlock

Fascinating stuff this and I think you are right Rodger :~))

Found the folllowing at various places :

Capillarity is the ability of a soil to draw water upward into tiny
spaces between soil grains; water moves upward against the force of
gravity because of the attraction between water molecules & the
surfaces of the soil particles.

osmosis :
http://www.tvdsb.on.ca/westmin/scien...ls/Osmosis.htm

And just to confuse the issue even more there is also reverse osmosis
.....http://www.howstuffworks.com/question29.htm

Jenny :~)

Trees in pots
 

In article , Rodger Whitlock
writes
On 19 Nov 2002 20:36:25 GMT, (DaveDay34) wrote:

it? Osmosis will operate until all the soil is truly saturated.

Osmosis doesn't operate until all the soil is saturated.

You are both confusing osmosis with capillarity.

It's capillary attraction that causes a pot standing in 1/2" of
water to become waterlogged, not osmosis.

To expand on that - osmosis is what happens when you have something -
for argument's sake, say salt - dissolved in water (or other liquid). If
you dump some salt in water, it diffuses across the whole lot so that
the strength of the solution is the uniform - you don't get a strong
salt solution where you dumped the salt and pure water elsewhere.

But if there is a barrier dividing the water into two, and this barrier
is such that water can get through but salt can't, the tendency is still
to try to even out the strength of the solution across the barrier, but
the only way this can happen is for water to go through the barrier from
the dilute side to the concentrated side. This is osmosis.

Capilliary action is the tendency for water to seep from wet area to dry
area - which can happen upwards if the route for seepage is small - eg
it's between the particles of soil.



--
Kay Easton

Edward's earthworm page:
http://www.scarboro.demon.co.uk/garden/

Trees in pots
 

"JennyC" wrote in message
...

"Rodger Whitlock" wrote in
message ...
On 19 Nov 2002 20:36:25 GMT, (DaveDay34) wrote:

it? Osmosis will operate until all the soil is truly saturated.

Osmosis doesn't operate until all the soil is saturated.

You are both confusing osmosis with capillarity.
It's capillary attraction that causes a pot standing in 1/2" of
water to become waterlogged, not osmosis.
Rodger Whitlock

Fascinating stuff this and I think you are right Rodger :~))

Found the folllowing at various places :

Capillarity is the ability of a soil to draw water upward into tiny
spaces between soil grains; water moves upward against the force of
gravity because of the attraction between water molecules & the
surfaces of the soil particles.

osmosis :
http://www.tvdsb.on.ca/westmin/scien...ls/Osmosis.htm

And just to confuse the issue even more there is also reverse osmosis
....http://www.howstuffworks.com/question29.htm

Jenny :~)


Reverse osmosis is what was used to turn sea water into potable water, when
I worked offshore. Cunning stuff them osmosis.
Chris S ))

Trees in pots
 

On Wed, 20 Nov 2002 12:36:24 +0000, Kay Easton
wrote:


But if there is a barrier dividing the water into two, and this barrier
is such that water can get through but salt can't, the tendency is still
to try to even out the strength of the solution across the barrier, but
the only way this can happen is for water to go through the barrier from
the dilute side to the concentrated side. This is osmosis.

Capilliary action is the tendency for water to seep from wet area to dry
area - which can happen upwards if the route for seepage is small - eg
it's between the particles of soil.

Yup, I got the wrong term. At school I believe they called it
capillary action. Anyhoo, I wouldn't want to stand a pot in water
unless it there was some charcoal or something else to sweeten the
water. It could get very fetid otherwise and full of nasties.

Hussein

Trees in pots
 

Sorry about confusing capillary and osmosis. I think I understood the jist of
what Hussein was saying and carried on using the same term, when I should have
corrected the term.

Dave.

Trees in pots
 

In article , Hussein M.
writes
On Wed, 20 Nov 2002 12:36:24 +0000, Kay Easton
wrote:


But if there is a barrier dividing the water into two, and this barrier
is such that water can get through but salt can't, the tendency is still
to try to even out the strength of the solution across the barrier, but
the only way this can happen is for water to go through the barrier from
the dilute side to the concentrated side. This is osmosis.

Capilliary action is the tendency for water to seep from wet area to dry
area - which can happen upwards if the route for seepage is small - eg
it's between the particles of soil.

Yup, I got the wrong term. At school I believe they called it
capillary action. Anyhoo, I wouldn't want to stand a pot in water
unless it there was some charcoal or something else to sweeten the
water. It could get very fetid otherwise and full of nasties.

Blanket weed is what I get, in the water surrounding my posts of sundews
and butterworts. But they don't seem to mind :-)
--
Kay Easton

Edward's earthworm page:
http://www.scarboro.demon.co.uk/garden/

Trees in pots
 

On Wed, 20 Nov 2002 16:33:42 -0000, "Chris Stewart"
wrote:

...Cunning stuff them osmosis.

I have a slightly used osmosi that you can have for a song if you
want it...

ObReportFromTheColonies: After a week or so of pretty steady
rain, varying in intensity from drizzle to downpour, the
temperature has gone up and the sun has come out today. It's
shirtsleeve weather, it's so mild.

Galanthus reginae-olgae is coming into flower. Crocus speciosus
'Albus' is providing surprises under a now leafless canopy of
Ribes sanguieum and Chaenomeles, while other crocus species
(longiflorus? niveus?) pop up here and there. A single stray,
late Nerine bowdenii, and a few stems of Nerine crispa. The first
flower of Iris unguicularis. A few seed pots sown last January
are showing signs of germination. The Quercus robur continues to
shed its leaves in a sedate and repeatedly eavestrough-filling
manner.

In the crocus frame, Cc. laevigatus, goulimyi, caspius (?), and
tournefortii are doing their thing.

Four of five seedlings of Cyclamen rohlfsianum have sent out new
growth; Cc. cyprium and creticum in pots are leafing out also.


On the whole, an extremely pleasant day!


--
Rodger Whitlock
Victoria, British Columbia, Canada

Trees in pots
 

On 20 Nov 2002 20:15:08 GMT, (DaveDay34) wrote:

Sorry about confusing capillary and osmosis.

Nothing to be sorry about. Mistakes happen. No apology necessary.


--
Rodger Whitlock
Victoria, British Columbia, Canada