[compost_tea] Re: Inclusion of clay in compost

From: Steve Diver <steved_at_ncat.org>
Date: Fri, 04 Feb 2005 16:54:19 -0000

Greetings Steve Steyn  -

Please read my summary and then perhaps
you can offer some clarity on what you
are describing.

First you talk about 10% clay in compost from
the CNC group in Holland, that specializes
in mushroom compost.  Apparently here:


CNC Grondstoffen B.V. / CNC Agricompost B.V.
http://www.cnc.nl/CNC-Summary-Main.html
_____ Dutch mushroom growers and CNC compost

It seems that is what you are referring to.
I'm not familiar with their compost from
first-hand observation.  Is it really finished
compost, or more akin to pre-digested organic matter
typical of most mushroom "composts."

There may be some confusion, because the CMC Compost
Group in Austria specializes in Controlled Microbial
Composting, in which they advocate the addition of 10%
clay for the purpose of clay-humus crumb, odor
control, cation exchange, microbial habitat,
and so forth.   CMC Compost is much more
widely used and appropriate for compost teas.

The CMC Compost system is primarily taught
through first-hand workshops.  The Luebke family
in Austria, organic farmers since the early
1960s, developed the CMC Compost system.

Bob Baars with Compara.nl in The Netherlands
also teaches CMC Compost, so there is a little
confusion as to which Dutch system you are
referring to.  See:

Compara.nl
http://www.compara.nl/engels.shtml

My paper on CMC Compost is still the most
comprehensive source on the web, located on
one of my personal web pages.

Controlled Microbial Composting and Humus
Management: Luebke Compost
By Steve Diver
http://www.ibiblio.org/steved/Luebke/Luebke-compost.html


Mushroom compost, as it is commonly called, is
notoriously not a finished compost. It is pre-digested
organic matter.  It can be useful as a soil amendment
for its fungal component, but it is not finished
compost and frankly I would frown on its use
as a compost tea substrate.   Often this material
is still in the thermophilic stage of decomposition,
with readily visible parent material such as straw
and manure.

CMC Compost, on the other hand, produces a
consistently high quality, premium-grade
humified compost.  That is what the CMC
system is known for, a consistent humified
compost with disease suppressive capacity,
as well as an excellent compost tea substrate.

Edwin Blosser at Midwest Bio-Systems in Illinois,
is prominent dealer of CMC compost systems, which
he calls ACS or Advanced Composting Systems. The
MBS compost workshops are one of the best compost
workshops you can attend, in my experience.  The
workshop notebook is an excellent source, well worth
the registration fee.  See:

Midwest Bio-Systems
http://www.midwestbiosystems.com/


Secondly, you jump to an "extration" process, which
I presume you are now talking about an aqueous
compost extract. 

There would never be "settling" of clay out of
CMC compost. The clay-humus crumb in CMC compost
is built by microbes. It is a masterpiece of
microbial architecture.   It would helpful for people
to know a little history of humus farming and the
agricultural pioneers who've contributed to this
knowledge system, including Selman Waksman,
Ehrenfried Pfeiffer, Siegfried Luebke, and Vaclav
Petrik.

Please feel free to elaborate in more detail.

Which system are you talking about, what
is your compost substrate, and what is your
Dutch compost tea making process.

Regards,

Steve Diver
http://www.attra.ncat.org


--- In compost_tea_at_yahoogroups.com, "Stephen Steyn" <ssteyn@w...>
wrote:
> A question for someone in the group;
> I intend using a compost for extraction  which has about 10% clay.
The rationale of the composters for including the clay is that they
believe the clay serves firstly to adsorb the cations and secondly to
moderate the temperature in the compost pile so that it doesn't build
up excessively. Both these arguments appear plausible. This composter
has done the CNC composting course in Holland where it would seem the
inclusion of clay is recommended. CNC are a company involved in the
mushroom business and it would appear they specialise in preparing the
feedstock for the mushroom farms namely a mix of lime, horse manure
and straw. You can check their web site if you like, Google CNC.
>
> The problem is that the extraction process commonly used here
consists of an airpump (I think its specs are 2500lt per minute at
2bar) with a membrane bubbler in the bottom of the 1500lt tank.
Extraction times are about 20 hours. No mechanical agitation is used -
again it's a system adopted from the Dutch. I have noticed though that
there is a build-up of clay in the bottom of the tank leading me to
suppose that the system is not  stripping the cations and biota from
the clay and that the clay is simply settling below and between the
bubblers without being agitated.
>
> I am having a sample of the compost tested through the kind offices
of SFI. I'm sure some knowledgeable person amongst you would like to
comment on the inclusion of the clay. I guess I should have a sample
of the tea tested and maybe test the clay from the bottom of the tank.
>
> Your comments/suggestions would be much appreciated.
>
> Steve Steyn ssteyn_at_w...





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Received on Fri Feb 04 2005 - 12:31:41 EST

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