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