On 06/07/15 15:03, Nick Maclaren wrote:
In article ,
Fran Farmer wrote:

I'm not finding much information on root oxygenation. I'm only finding
information in hydroponics sites (which accords with the indoor growers
of certain substances as a source) but that doesn't seem to have a great
deal of application to gardens or my water tanks (=huge butts). I'll
keep hunting.

Try looking for root aeration. I am pretty sure that plants that
can live in bogs and stagnant water can live without oxygen at
their roots, but almost all others need it.

Any idea if roots excrete material unwanted by the plant? I wonder if
the stagnation isn't just lack of oxygen, but concentration of something
toxic around the roots (not only from decomposing plant or non-plant
material). Not just toxic to the plant, but maybe to any mycorrhizal
fungus associated with the plant.

It's interesting that many plants can be grown pretty much with their
roots soaking wet all the time if the medium is moving (as with
hydroponics). That would allow continuous oxygenation, but also remove
anything hanging around the roots.

--

Jeff

On 06/07/2015 22:09, Chris Hogg wrote:
More of a political gesture than a practical measure to prevent
terrorists synthesising acetone peroxide. Any terrorist capable of
that synthesis would know how to concentrate H2O2 to the required
level. It's not difficult.

Like the one where they confiscate your toothpaste.

It's interesting. I actually chickened out of posting the reason. What a
world we live in...

Andy

On 7/07/2015 12:03 AM, Nick Maclaren wrote:
In article ,
Fran Farmer wrote:

I'm not finding much information on root oxygenation. I'm only finding
information in hydroponics sites (which accords with the indoor growers
of certain substances as a source) but that doesn't seem to have a great
deal of application to gardens or my water tanks (=huge butts). I'll
keep hunting.

Try looking for root aeration.

A quick update: I have had absolutely no luck at all using "root
aeration" as a search criteria to find any information that sheds light
on the OP's question about oxygen in water.

"Root aeration" search results only show information about getting
oxygen to the roots of plants not "oxygen in water" getting to the roots.

It seems that "root aeration" does not equate to "oxygen saturation in
water". I've decided to become unfixated on the issue as I suspect it's
not important unless I want to go into hydroponics.

In article ,
Fran Farmer wrote:

I'm not finding much information on root oxygenation. I'm only finding
information in hydroponics sites (which accords with the indoor growers
of certain substances as a source) but that doesn't seem to have a great
deal of application to gardens or my water tanks (=huge butts). I'll
keep hunting.

Try looking for root aeration.

A quick update: I have had absolutely no luck at all using "root
aeration" as a search criteria to find any information that sheds light
on the OP's question about oxygen in water.

"Root aeration" search results only show information about getting
oxygen to the roots of plants not "oxygen in water" getting to the roots.

It seems that "root aeration" does not equate to "oxygen saturation in
water". I've decided to become unfixated on the issue as I suspect it's
not important unless I want to go into hydroponics.

I probably could, but would have to search for research papers, and
it would not be quick. No, I don't know what research has been done.
This is what I believe, from prior reading.

They don't equate, but are related. You need a lot of oxygen in the
water only if there is no air getting to the roots - as you say, that
is generally important only in hydroponics (and for water plants).

I can, however, believe that the hydrogen peroxide trick helps under
some circumstances, possibly including pot plants with broken-down
peat-based compost.


Regards,
Nick Maclaren.

On Wed, 08 Jul 2015 13:58:07 +1000, Fran Farmer wrote:

It seems that "root aeration" does not equate to "oxygen saturation in
water". I've decided to become unfixated on the issue as I suspect it's
not important unless I want to go into hydroponics.

That's right. I was interested in oxygen saturation in water because I
was concerned with compacted, wet soil in pots. In that situation, roots
have a difficult time getting oxygen, which they need.

Maybe this link will help illustrate what I'm talking about. It refers
to soil compaction after flooding, but I've heard watering pots over time
compared to this.

http://hillsborough.ifas.ufl.edu/pro...blications/HC-
SoilSaturation.pdf

Bottom line, roots and symbiotic mycorrhizae need oxygen. If the soil is
in good condition and dries out, they get it from pore space in the
soil. If not oxygen saturation (and hence H2O2) can play a role.



--
Gardening in Lower Normandy

On 2015-07-06, Chris Hogg wrote:

I note that 35% H2O2 isn't available in the UK and more. Apparently
it's illegal to sell it. Maximum strength allowed these days is 12%.
So that would be 7.5ml of 12% in 10 litres.

Last time I bought some, the pharmacist told me they were *only*
allowed to sell 12% now --- i.e., you can't get 6% so you have to
dilute the stuff they sell in order to use it as a topical
antiseptic. Strange.

On 8/07/2015 7:34 PM, Emery Davis wrote:
On Wed, 08 Jul 2015 13:58:07 +1000, Fran Farmer wrote:

It seems that "root aeration" does not equate to "oxygen saturation in
water". I've decided to become unfixated on the issue as I suspect it's
not important unless I want to go into hydroponics.

That's right.I was interested in oxygen saturation in water because I
was concerned with compacted, wet soil in pots. In that situation, roots
have a difficult time getting oxygen, which they need.

Maybe this link will help illustrate what I'm talking about. It refers
to soil compaction after flooding, but I've heard watering pots over time
compared to this.

http://hillsborough.ifas.ufl.edu/pro...blications/HC-
SoilSaturation.pdf

Bottom line, roots and symbiotic mycorrhizae need oxygen. If the soil is
in good condition and dries out, they get it from pore space in the
soil. If not oxygen saturation (and hence H2O2) can play a role.

Thanks Emery and Nick for clarifying and confirming my understanding on
this issue. I've not ever been tempted by hydroponics (I get into
enough growing issues without that complication) but will stash this
snippet of knowledge into the back blocks of my memory banks just in a
case I ever do become tempted.

On Wed, 08 Jul 2015 16:52:37 +0100, Chris Hogg wrote:

Out of interest, how do composts based on coir perform? Are they as
prone to degrading to impermeable humus as peat, or do the coir fibres
help maintain an open structure?

I'm using coir now, with very little peat. Seems to have all the same
problems. Perlite helps, lots of it. Wish I could get composted pine
bark here, I've found a place but it's a 3 hour drive (each way) and of
course they're closed for 6 weeks this summer!



--
Gardening in Lower Normandy