Re: [compost_tea] pumps and long hose effects

From: <soilfoodweb_at_aol.com>
Date: Mon, 4 Oct 2004 03:21:52 EDT

Thank you Bob for sharing a great example of data showing that the equipment
you are using is not harming the fungi, and presumably not harming the other
organisms as well - could you share that data as well, Bob?

There is variability in organism biomass and activity, of course, and
generally, the coefficient of variability for organism data IN SOIL is about 17% to
20%, as we showed in about 10 publications that are in the scientific
literature.

What the heck does coefficient of variability mean?

That whatever number you have could be less by 17%, or higher by 17%, if we
took sample, after sample, after sample.

Compost tea is less variable than soil, with a coefficient of variation of
about 10%. That info is in the compost tea brewing manual.

So, with a mean value of 16 micrograms (which should be a greek letter mu,
not a m, just to get picky with you Bob).

I know there's a lab out there claming they have measured teas with 220,000
micrograms/ml - or 220 mg/ml- of total fungal biomass in compost tea, but that
just isn't possible. There's a mistake in their computations. If you had 220
 micrograms of fungal biomass per ml, you would not be able to get the tea
out of the nozzle of a sprayer, it would be so choked with fungal material. We
want to be able to spray tea just like water.

Anyway, I'm allowing myself to be distracted, sorry, back to topic.

Coefficient of variation. If the value on the SFI report was 16, then it
means that another sample of the same material might have a reading 10% higher or
lower, so subtract 1.6, and add 1.6, and you get the possible range of what
might have been seen if another sample had been taken.

So, the range is between 14.4 and 17.6 micrograms/ml. The sample coming out
the hose is within the range of probable variation, and thus, we can safely
say that the equipment had no effect on the fungi in the tea.

OK? was that clear? Or did I confuse people?

Elaine R. Ingham
Soil Foodweb Inc., Corvallis, Oregon
Soil Foodweb Inc., Port Jefferson, New York
Soil Foodweb Institute, Lismore Australia
Soil Foodweb Institute Cambridge, New Zealand
Soil Foodweb Inc., Oosterbeck, The Netherlands
Laboratorios de Soil Foodweb, Culiacan, Mexico
Soil Foodweb Inc., Jerome, Idaho
Soil Foodweb Inc., South Africa







Received on Mon Oct 04 2004 - 04:31:43 EDT

This archive was generated by hypermail 2.3.0 : Tue Feb 07 2012 - 14:15:30 EST