"Salty Thumb" wrote in message
...

Diamon also having high C/N ration, I can assure you it will not
reduce the N available to plant when use as mulch. g

Diamonds (?) do not contain any biologically accessible carbon.

Yes, "diamond" not diamon.

This is my point, it's the carbon available to bacterial, not the
actual amount of carbon that causing temperary N deficiency.

If the carbon do in a slow release form for bacterial, it will not
cause a suddent bacterial bloom even there is a lot of carbon there.

It really depend on the available carbon instead of the total
carbon
contain.

Both newspaper and sawdust have high cellulose percentage. Sawdust
is
reported to reduce nitrogen availability when used in a compost
pile.

I believe that is starch and sugar in the sawdust that cause this, not
cellulose or lignin. I believe newspaper do lost some of it starch and
sugar while in the process.

I believe mulch will reduce N available to plant when the
carbon(in
liquid form) leach to the soil in rain, but not when there is no
water
soluble carbon are present in mulch.

Many forms of N are water soluable and is leached away by water
without
any interaction with C, mulch or newspaper. You may actually get
additional N during rain.

So, either mulch will cause temporary N deficiency or not will depend
on the C/N ratio make available by rain to soil bacterial.

I will say that, some mulch will and some mulch will not causing
temporary N deficiency. It will depend on the amount of the C and N
available to bacterial that do bring to soil by rain water.

In my impression, newspaper does not contain much water soluble
carbon. It need enzyme to convert it, and that is a slow process.

Cellulose is broken down by actinomycetes.

I believe this process are rather slow. Do actinomycetes got the
ability of N fixation from air?

If I'm not wrong, cellulose are not one of the form of carbon that
directly available by bacterial.

Despite the name and superficial resemblance, actinomycetes are
prokaryotic bacteria, phylum actinobacteria. (Fungi are all
eukaryotic.)

To tell the true, I don't know what is actinomycetes. g

'soil life'

Thanks. :-)

To explain my view, this will become a very long posting.

One of the example of the cost I refer are stocking cost,
purchasing
cost(time spend on searching, barginning...), disposing
cost(collect
and send to landfill..._)...

It is not necessary, I do not think the orginal poster is concerned
with
those things.

You are right.

Have you read the sci.bio.agriculture group?

I do take a look there when I looking for agriculture newsgroup few
month ago. Forgetted why I decide not to subscribe this group. May be
due to the lack of traffic, or it's more on academic than practical.
Not sure.

Do you think it's good for me to looking information there?

From what I read, all the earthworms will not like to expose under
the
light.

They also prefer to avoid becoming lunch.

g

If you read the link I posted earlier,

I'm doing a research for X/HTML now for writing some program, will
read the link you provide later.

it classifies earthworms in 3
groups. One of them i don't remember and is probably not relevant.
The
other two are nightcrawlers and regular earthworms.

IIRC:
1. Litter dweller. Those live in the litter/mulch. E.g. red worm for
worm composting
2. Surface dweller. Those "regular earthworms" work their way most of
the time horizontally.
3. Burrower. Nightcrawler/dew worm.

Another link I
provided gave the population density for a certain species at some
test
location as 0-7 per sq. meter. At this rate, and the size of my
flower
bed, I think any detrimental effect by landscape fabric is minimal.

The reason of some place are 0 per sq. meter, the other are 7 per sq.
meter are due to the environment of that place.

I do believe that for a same place, a landscape fabric do reduce the
earthworm population by reduce the accessability to food for
earthworm.

I think, since it is a worm, eventually it will reproduce at a
sufficent
rate to exploit any available opening.

Yes, to a far lower population in the total area.

The other kind of earthworm does
not live in static burrows and only comes out during times of rain.
I
would guess that being subterranean, they would also be minimally
affected by landscape fabric.

They do need food, the landscape fabric do block organic matter to
reach the soil. If you mixed in a lot of manure yearly to the soil
that is another story.

I don't think plant roots are impermeable to water. I don't know
how a
chunk of clay is going to get into my flower bed. It has been
several
years and I have no problems with water blockage. Even if some clay
or
other amendment (as below) were spread over the fabric, water is a
very
effective solvent and while the clay or amendment is not guarranteed
to
pass, the water certainly will.

It do reduce the infiltration, and causing run off when rain are
relative heavy.

You can try this experiment: Cover some soil with newspaper. Time
how
long it takes to develop an opening. It takes over 2 months in a
temperate climate.

Put other organic mulch on top of newspaper, it make difference.

Any holes that develop are not from macroscopic
organisms.

I believe soil life do included those like earthworm, groundbettle,
millipede, fungus...

Plants will grow through, but those opening are not
available
to macroscopic organisms (being blocked by the plant).

Plants roots will dead, especially feeder roots, after the dead roots
decay, tunnels are there. This applied to fungus as well.

I will be surprised if you can come
up with any large organism (other than termites, paper wasps and
people)
that will deliberately make a hole in the newspaper.

Here I do saw rat making big holes anywhere. ;-)

To be fair, cover
half the newspaper with organic mulch (I have not tried this) and
see
what happens. You can cover the other half with a banana leaf or
something if you are worried about sun effects on organisms (you can
take
the leaf off when it rains or artifically add water to simulate tho
condition). I predict the only difference is that mulch side will
have
accelerated decomposition (1 month to first hole vs. 2 months).

It really depend on how abundant life form are there. An example are,
I put the newspapers under my curing compost that have abundant of
groundbettle, millipete, earthworm... I do quite sure it take less
than three days to have a first hole that go through all the layer of
newspaper if the newspaper are wet.

It's not just the size of the hole but also any electrical or
chemical
effects that may cause what ever you are adding to clump together
(similar to hard water calcification of drain pipes on a smaller
scale).
Also, the landscape fabric regardless of the holes may be
semi-porous to
water. That is not necessarily true for the solute. [by 'hole' in
this
case, I'm refering to the factory made approx. millimeter sized
openings
uniformly distributed over fabric area, not the openings made by
users to
plant through.]

My point are, if the end result are nutrient in liquid form can be
filter/block, it's sure that it also will causing run off, and not
much water can get from rain for soil that is directly under the
landscape fabric. So why landscape fabric? ;-)

Sure, if the rain are long and light, it's another story.

Your peanut groundcover is more likely to grow to 2 meters tall and
start
dancing around with a top hat, cane and monocle.

g

Cheers,
Wong

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