Re: [compost_tea] : non-aerated teas/ Aerated comparrison tests
If someone else has a method they use that measures what we need to know in
soil or compost tea, let me know!
What do we need to know?
1. We have the organisms that will be able to suppress disease, protect
leaf surfaces, etc. Much of this work is being done, but on a species by
species level. The EPA testing requires that all species be known in a material in
order to register. But, we don't know all the species in milk, for example,
but people can buy it to drink. We don't know all the species present in
bread, but you can buy bread.
It is as if the EPA is demanding a higher level of knowledge for products
that aren't even consumed by humans than we have for products being eaten by
people.
What's the story? Follow the green stuff......
So, for the time being we can't make claims of disease suppressiveness when
we sell compost or compost tea. But you can show people scientific papers
that show that certain species of bacteria or fungi or protozoa are bio-control
agents, and you can show that these organisms are present in your compost or
tea.
Can't make claims. You have to leave the consumer to make the conclusions.
Use of plate methods to isolate and ID specific bacterial or fungal species
works fine. So, SFI offers that ability, as does BBC, Agri-Energy, and a few
University labs. Your choice. Cost is a couple hundred dollars per test
run.
But SFI has shown - in a paper in peer review right now - that the
relationship between DNA sequencing and direct methods of assessing total biomass,
that there is a good relationship between these two things. So, you want to pay
several thousands of dollars for that info, or $25?.
What else do we need to document in compost or tea?
2. Nutrient retention. Make sure leaching is not a factor in your soil.
Don't need to know species here. But you do need to know that you have the
biology present that will do the retaining. So you need to know active
bacteria, active fungi, total bacteria, total fungi. An understanding of compaction
in your soil is useful too, so do a soil penetrometer measurement. (Check
with your closest SFI advisor or other soil consultant).
3. Nutrients being cycled into forms your plants need. You need to know
the predators in the soil - protozoa, nematodes, microarthropods. SFI is about
the only lab doing all three assays, but there are a couple University labs
that do nematodes in a responsible fashion. There are a couple labs in
California and Western Labs that have a nematode specialist who do a good job.
SFI has just found a person to do microarthropods. Most ag soils don't have
microarthropods to speak of if they are tilled more than once a year. So,
perennial systems may be the only ones where this info is useful..
4. Mycorrhizal colonization of roots - need to know if you need to add
mycorrhizal spores.
5. Ability to build soil structure - you need to know ACTIVE bacteria and
fungi, TOTAL bacteria and fungi, protozoa, nematodes, arthropods.
Plate methods can't help you on any but the species isolation and ID. Other
common soil methods can't help either as they don't differentiate bacteria
from fungi reliably. Measuring CO2 doesn't tell you what you need to know
either, as if just gives a general assessment of soil respiration, and diseases
respire just as well as non-disease organisms.
So, as I said, happy to develop some other way to measure the organisms in
compost or compost tea, if folks can demonstrate that there is a use to it, or
that it doesn't cost an arm and a leg for growers to get that info.
Elaine
Hi Ted-
Will other labs measure the essential differences between ACT and NCT? If
so I have no reason to insist on SFI. For instance, would plate tests reflect
essential comparisson information? Would the simple quick microscope
readings tell us essential differences? Will SFI tests prove essential differences
in the TEA? Soil? Plants? Nutritional differences?
Pissing contest? Not intended. Just offering an outline for a near
standard engieering test. Each tester still has many blanks to fill in as to the
details they will use. Do you have suggestions to ease, simplify, improve ?
Others allowed to take the form? Intended for any use that is wanted. It
is a formatt written for this test for any who wish to use it or any parts of
it. Any tests need some reported information to come close to proving what
we need to know. Bob
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
Laboratorios de Soil Foodweb, Culiacan, Mexico
Soil Foodweb Inc., Jerome, Idaho
Soil Foodweb Inc., South Africa
Received on Mon Jan 17 2005 - 17:04:21 EST
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