Subject: Re: Species diversity

From: Joel Gruver <[email-masked]>
Date: Wed, 6 Nov 2002 08:37:55 -0500

Hello Elaine,

As I stated in my previous post, I completely agree that plate counts are
not a very useful research method for evaluating total or active microbial
biodiversity.

My point is that for routine testing purposes (i.e. which require  rapid and
cheap methods) I think that a plate count method may have value for routine
assessment of the functional value of compost teas.
This is my hypothesis. I have not personally tested this hypothesis.
Hopefully any labs using plate count methods to evaluate the quality of of
compost teas have tested this hypothesis.

You wrote:

>The connection between nitrate and plant uptake and response is easy >to
>see, because nitrate is so soluble and so mobile.

This is not accurate... very few soil testing labs analyze (routinely) for
nitrate because the relationship between levels of nitrate in soil samples
(collected before the growing season) and crop response is normally very
weak. There are some exceptions such as PSNT (where samples are collected
immediately before a rapid phase of plant growth) and also in arid regions.

>But this isn't the case for P, for example.

There is plenty of evidence that routine soil tests for P frequently have
good ability to predict crop response to P inputs.

The Melich 3 (and other extractants used commonly for routine soil testing)
do not extract the exact pools of P (or other nutrients) that are used by
crops during a subsequent growing season. The Melich 3 extractant simply
extracts a quantity of P that consistently allows prediction of need or lack
of need for additional P.

Just as routine tests for soil nutrients have value despite not revealing
the full range of pools of nutrients that may be accessible by crops (or the
mechanisms by which these pools are accessed), I am suggesting that a
routine test of compost teas (using plate counts)
may have predictive value despite only presenting a small window into the
biodiversity of compost.

>Mycorrhizal fungi, for example, cannot be cultured on any plate medium.
>That seems a huge set of beneficial organisms that are completely missed by
>plate counts.

This is not true - the literature contains lots of evidence that that plate
culture of ectomycorrhizae is possible and is a useful scientific method.

Joel

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From: Steve Diver <[email-masked]>
Date: Wed, 6 Nov 2002 12:15:11 -0600

I guess I should alter this for clarity.  It is sometimes helpful to
read a "second" viewpoint.  What I mean to say is that
Johnny Agulia confirms what Elaine Ingham has been saying
about the plate-count vs direct-look method.

Direct-look is a colloquial term for the microbial bioassay
method developed by Dr. Ingham through her graduate
research and introduced as a commercial lab service during
her tenure at Oregon State University.  It uses high-end
epiflourescent microscopy to visually observe and measure
bacteria, fungi, protozoa, and nematodes.

Steve Diver

> It is sometimes helpful to read a different viewpoint. In the
> following piece, Johnny Agulia at ABC ORGANICS summarizes
> the difference between "Plate-Count" and "Direct-Look" methods
> for microbial analysis.  Be sure to read the "French Poodle effect"
> to gain a hands-on appreciation for the biological farming approach
> versus the NPK farming approach.
> http://www.abcorganics.com/Compost%20Production.htm
>
> Adios,
> Steve Diver

.

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From: Steve Diver <[email-masked]>
Date: Wed, 6 Nov 2002 10:51:37 -0600

Still, there are other uses of plate counts...

One useful aspect of plate culture is to look at potential
for disease suppression and pathogen inhibition, by
microbial cultures or with compost samples.  Make a
compost extract and put your sample in there and let the
critters duke it out.

See:
Pathogen Inhibition Assay @ Bob Baars site
http://www.compara.nl/what_compost.htm

It is also interesting to just grow out microbes from composts
and soils and microbial inoculants.  You can "see" diversity for
yourself as the different microbial cultures start to grow on a plate.
Compare high diversity plates to low diversity plates -- a contrast
between well managed soils and neglected soils -- and you start
to get the idea what diversity is all about and why it is important.
There is a memorable piece in the Japanese "Life in the Soil"
video that illustrates this point.

You can also select microbial cultures that start to grow from soils
or composts, identify them by mass spectrophotometry, then culture
them, then add them as an adjunct to compost teas and liquid
biologicals.   Agri-Energy Resources in Illinois is doing this
on a commercial basis.
http://www.agrienergy.net/products/indexproducts.html
http://www.agrienergy.net/products/research_data.htm

The power of this approach can be understood from Midwest
Bio-Systems' experience in the Georgia vegetable grower's field,
where a virus in bell peppers was "arrested" through an
integrated eco-farming approach that included mineral balancing,
high quality compost application, and amended compost teas
obtained from Agri-Energy Resources.  Getting a vegetable crop
to grow out of virus infection through organic and biological farming
practices is a *major* development.

No wonder people are so upset about the NOP rules on
compost teas.  The sophistication among organic farmers and
crop advisory labs to implement advanced biological farming
aproaches -- such as sophisticated compost tea blends -- is
years ahead of 95% of the land-grant university of USDA
programs.

Incidentally, Agri-Energy hosts this piece that I am fond
of passing along; a synopsis of European and American
viewpoints on the importance of soil life and humus management.

The Soil Life - Humus - Soil Fertility Connection
http://www.agrienergy.net/renewabledata/soil%20life%20humus/soillife.html

Likewise, Midwest Bio-Systems hosts this piece on compost
quality.

Distinguishing Compost Quality
http://www.aeromasterequipment.com/compostquality.html

And this piece,
University Research on ACS Compost from Midwest Bio-Systems
http://www.aeromasterequipment.com/universityresearch.html

Adios,
Steve Diver

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From: Steve Diver <[email-masked]>
Date: Wed, 6 Nov 2002 10:51:37 -0600

See:

And this piece,

Adios,
Steve Diver

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