Re: [compost_tea] Re: Inclusion of clay in compost

From: butch ragland <wilddog_202_at_yahoo.com>
Date: Sun, 6 Feb 2005 14:04:35 -0800 (PST)
This does not directly feed into this discussion.

At the compost facility we would receive tree stumps
including roots. They were covered with compost for a
period before we ground up the stumps/roots. Included
were fairly large clumps of soil, some heavy clay. All
this went into the pile, alter truning for a period of
time it was run through a screen. The clump size was
reduced and after screening, windrowing and turning it
all disapeared. Simply could not be found without a
microscope. Finally, depending on the processing
method it doesn't matter what size clay is added to
the pile.

--- Stephen Steyn <ssteyn_at_wcaccess.co.za> wrote:

> To all those who contributed to the clay story.
> Here's a bit more.
> Thank you most kindly for your thoughts.
> I asked my composter when she was teaching me to
> make compost "What type of clay?" Should I use
> Kaolinite which you may know is used for porcelain,
> pottery, roofing tiles and bricks? In fact it was
> first used in China to make porcelain and they held
> the monopoly, which is why porcelain dishes are
> called china. Of course subsequent discoveries were
> made in Georgia and the colonists exported it to
> Cornwall where they made Wentworth pottery. It's
> also used in paints, high quality paper, ceramics
> for electrical insulation and heat shielding (like
> the tiles on the belly of the space shuttles) and
> mothers will know it from Kaopectin-type medications
> where it is used to line the stomach walls and
> inactivates diarrhoea- causing bacteria by adsorbing
> them on the clay particle surfaces. I digress.
>
> Many of the arguments about absorption of cations
> fall away if you use Kaolinite. Its one of the most
> common 1:1 clays and has a cation exchange capacity
> (CEC) of virtually zero. Maybe its ability to adsorb
> bacteria as in the stomach remedy is important
> though. Its properties are good for plates as it
> doesn't expand and contract when fired but as a soil
> amendment for agricultural purposes its of limited
> value.  Humus has a CEC of 150 to 250. High activity
> clays (expanding 2:1 silicates like smectite and
> vermiculite, and non-expanding 2:1 clays like
> fine-grained mica and chlorite) would be a better
> bet - although most of the charge on humus and low
> activity clays is pH - dependent, becoming more
> negative as pH rises. No I'm not a smart ass, I took
> the above from the book  Nature and Properties of
> soils, 13th edition, by Nyle Brady and R Weil,
> Prentice Hall Printing. Mostly pages 326 and 360.
> What I'm trying to say is it seems important to
> define the clay you're using and obviously it should
> be finely ground.
>
> The argument for stability would be ok if the
> compost were to be applied to the soil. As an
> extractor feedstock this would be less desirable as
> one would possibly like the biota released more
> quickly. The argument for heat build-up in the pile
> probably also has merit but as Ingham says, the pile
> probably has too narrow a C:N ratio to start with -
> the mix is too "hot". I should of course have taken
> a sample from the deposit in the extractor and sent
> it to SFI to be analysed and maybe got more clues as
> to its content.
>
> Without causing trouble, how do SFI tests compare to
> those performed by the  CMC composters as outlined
> by Steve Diver in his interesting paper on CMC
> compost. Has anyone compared the two?
>
> Steve Diver also mentions Bob Baars as a European
> expert on CMC technology. I will mail him during the
> week and get his thoughts on the use of clay in an
> extractor feedstock..
>
> Thanks for all the responses.
>
> Steve Steyn


=====
Butch Ragland
Conflict is as addictive as
cocaine, alcohol, cigarettes,etc
I'm sorry to report that
cooperation is not

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Received on Sun Feb 06 2005 - 18:48:29 EST

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