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Subject: Compost Teas: 24 hour, EM, IM, BD & fermented plant extracts

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  • From: "Soil Foodweb, Inc." <info AT soilfoodweb.com>
  • To: compostteas AT lists.ibiblio.org
  • Subject: [Compostteas] Compost Tea Brewing
  • Date: Sat, 11 May 2002 22:10:28 -0500

Hello Compostteas list!

I'm excited about this new list serve. I've never belonged
to a list serve before, so this will be an adventure for
me. Usually too busy to monitor something like this, but
for this list, I want to be here to read and answer
questions.

Who am I? One of the first people to do experiments that
show that compost tea can prevent disease organisms from
killing plants. We used direct counts of active organisms
on leaf surfaces, combined with visual evidence of disease,
to show that to prevent disease on plants, a minimum of 70%
of the leaf surface has to be covered with the organisms you
grow in the compost tea. That 70% coverage has to be at
least 5% fungal coverage, or you just can't have suppression
of the problem fungal diseases when disease pressure is
intense. Bacteria alone can do the job if you don't have
really bad disease pressure, but will you have bad disease
or not this year? You don't know, so you have to protect
the leaves fully.

That's what is lacking in plate count and carbon dioxide
measurements of compost tea. The designation of "good",
"bad", or "moderate" that are used by plate counts, or CO2
evolution, labs are not linked to whether these teas will
prevent disease organisms from infecting the plant. Where's
the data that shows that disease will be reduced? I am not
aware of any such information available from them.

Where's the data that show activity of the organisms on the
leaf surfaces prevent diseases from gaining a foothold on
leaf surfaces? We have a series of experiments that we are
repeating on a number of plant species, and when we get them
all done, we'll publish in Applied Soil Ecology, or Biology
and Fertility of Soils, two of my favorite publications. In
the meantime, the data from our experiments are summarized
in the Compost Tea Brewing Manual, by Elaine R. Ingham,
Ph.D., available from Soil Foodweb Inc.'s website,
www.soilfoodweb.com

The pictures from the experiments we did, showing conclusive
evidence of why compost tea works and can prevent disease
organisms from growing on leaf surfaces, is available from
www.unisun.org Please check their website to get the Slide
CD from SFI.
-----------
There are current controversies about compost tea, the most
recent being the one about addition of sugar in teas. Lots
of rumors flying, no hard data published by those who say
addition of sugar results in the growth of E. coli,
Salmonella and Shigella in tea. There are three experiments
that are being used to try to change the National Organics
Standards about compost tea. These apparently are in peer
review and have not appeared in the scientific literature
yet.

The closest thing there is to hard data that anyone can find
is two talks given at the Biocycle Compost meetings just
finished in Ohio. One of the talks showed that if liquids
containing extracts of compost, to which rich food resources
were added, and which were inoculated with human pathogens,
allowed the pathogens to grow. This is not a surprise.
Pathogens will grow in your soup, or coffee, or macaroni and
cheese if you inoculate the materials with the organisms,
reduce oxygen, keep the temperature warm, and give the
organisms long enough to grow.

So? Why would you suspect this would not happen? Feed the
pathogens exactly what they need, reduce oxygen levels so
aerobic competitive organisms will not be active, and E.
coli will be able to grow. These experiments were done ad
infinitum in the sewage treatment world years ago.

However, a second talk, based on work performed by BBC Labs,
showed that E. coli grew in the tea during brewing in a
Growing Solutions Inc.tea maker. Verbal descriptions that I
have heard about the talk from several sources suggest there
were significant flaws in the design of the experiment.
These flaws were that oxygen concentration was not correctly
measured in the experiment. The "compost" used in the
experiment contained E. coli, and so did not meet the
standards established for compost. In other words, it
wasn't really compost tea, it was putrefying organic matter
tea. The "tea" made was not compost tea, by definition.
Extrapolation from this set of experiments with one tea
maker under conditions that are not what is called for by
compost tea production specifications to compost tea in
general is not valid.

But we need to wait until the PUBLISHED, PEER-REVIEWED
version of the paper comes out so every one can see exactly
what was done. We need to look carefully at the
limimtations of the experiment, see where there needs to be
more extensive work done to corroborate that work, or to
clarify flaws. There should be no change in the "rules" for
making compost tea until the science is fully examined and
reasonable conclusions are reached, based on more extensive
testing. For recommendations to be made to the National
Organics Standards Board to dis-allow the use of molasses,
sugar or other carbon-containing materials in tea on the
basis of these experiments is over-reaching the logical
conclusions of these limited set of tests.
----------
We have been doing E. coli testing at SFI for quite some
time on teas. E. coli does not normally grow in aerated,
high organism count, high organism activity and diversity
tea. But the critical points are that the tea must contain
at least the required biomass and diversity of active and
total bacteria and fungi, and must remain fully aerobic
through the whole brew.

Some people have questioned that I am self-serving to test
tea for E. coli, when I am such a proponent of the use of
compost tea. So, in the next set of experiments that we
will run, we will use an independent lab to assess E. coli.
We will make sure that aeration is maintained at the levels
compost tea must be kept at to prevent the growth of harmful
bacteria. We will make sure that all the competitive
organisms needed in the tea are present. Testing tea is
critical - and you have to know whether the competitive
organisms in the tea are ACTIVE or not. You cannot measure
active organisms using plate counts, you can only measure
viable organisms. There's a huge difference.

Here at SFI we have a SARE grant in it's second year. The
initial data from year one are on the USDA - SARE web site
showing that the coverage of the leaf surfaces are critical
to prevent mildew and grey mold on grapes. If you don't
make sure the tea has the organisms needed, you may not have
the disease preventative conditions you need to keep the
disease orgnaisms from causing problems. We have just
started the second summer of testing in the tea grant. This
experiment will finish in the summer of 2003, so the data
will be published after that.

We also have an experiment going this spring, where we are
looking at replicate data from each type of compost tea
making machine on the market. This study is funded by a
group of growers. We will have data from each of three teas
produced by different growers all over the country, to show
how repeatable each type of tea making machine is in making
tea. You would be amazed at the variability of some
machines. Really, the only machines that reliably produce
excellent tea have repeated sets of data from SFI posted on
their websites. For example, the new KIS machine has data
posted (www.simplici-tea.com). The EPM machines have posted
data (www.compostea.com). The 25 gallon-enhanced tea maker
offered by Hendrikus Schraven Organics has posted data
(www.hendrikusorganics.com). All of these show that their
machines make teas with excellent levels of organisms when
the right compost, food resources and adequate aeration are
used. The Sottilo machine, the Earthworks machine
(www.soilfirst.com), the Alaska Bounty machine, the Freedom
Organic machine, the Hronek machine, and others coming down
the line all will post data once they are actually in
production. Stay tuned to the SFI website and e-zines for
this information.

All the machines with data displayed on their websites have
been documented to maintain excellent oxygen concentrations
when the sugars added in the recipe are reasonable, and they
all have been tested to make sure that E. coli does not grow
when GOOD, AEROBIC compost is used. Even though sugar,
molasses and other high carbon containing materials are used
in the tea recipe, E. coli was not detected in these teas.

How do I know? We tested them, although not
three-replications per run. Look-see data is not
publishable in scientific journals, although it is good
enough when you are monitoring for a problem condition.
We'll re-test everything, as the tea makers direct us, but
the worry about sugar in tea causing the growth of E. coli
is not real, I believe, IF aeration and organism activity is
maintained properly. Of course, we can't tell for certain
until we all see the published data. You need to see the
published data from SFI as well. and it will be forth-coming
after we finish replicated trials.

We only see E. coli produced in teas where aeration is
inadequate in the tea maker, and where poor quality compost
is used. There has to be a source of the human pathogens,
which can only come from poor quality compost. Second,
there has to be limited sets of beneficial, aerobic
organisms, which can only occur in poor quality compost, or
where amendments added to the tea kill the beneficial
organisms. And finally, aeration has to be inadequate.

Are there commercially produced tea machines that have these
problems? Yes. These tea machines do not show any data
about aeration or ACTIVE organisms in their teas on their
websites. They will not give you data about the BIOLOGY
their tea machines produce, even if you ask them to give you
the data.

Remember, it's the active organisms in the tea, not the
viable organisms. OK? Questions.... please ask.

Sincerely,

Elaine Ingham
President, Soil Foodweb Inc., Corvallis, Oregon
Adjunct professor, Southern Cross University, New South
Wales, Australia





  • [Compostteas] Compost Tea Brewing, Soil Foodweb, Inc., 05/12/2002

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