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Re: Regulation of compost teas (was: NOSB loses its head)
[exerpted from the SFI, Inc., Soil Foodweb Newsletter, August 2002
archived at:
http://www.ibiblio.org/ecolandtech/pcwiki/pcwikiufu/August2002Ezine.txt]
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Dr. Elaine Ingham
Soil Foodweb, Incorporated
info@soilfoodweb.com
http://www.soilfoodweb.com/phpweb/
AUGUST 2002 EZINE
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What is the Soil Foodweb?
"What is soil? · Bedrock weathered into parent material, or the sand, silt and
clay fractions. These fractions
hold the minerals, typically measured as CEC, or cation-exchange capacity. The
minerals held in the sand,
silt and clay are NOT plant available and must be processed by bacteria and
fungi, protozoa, nematodes or
microarthropods to become plant available. · Organic matter, which is food to
feed the organisms. ·
Bacteria, fungi, protozoa, nematodes, microarthropods. · Soil aggregates
are built by the bacteria,
fungi, protozoa, nematodes and microarthropods using organic matter and the
sand, silt, clay.
The least productive soils in the world are those with the least amount of
organic matter and the least
complex food webs, which mean the fewest numbers and diversity of soil
organisms. The least productive soils
will be nearly 100% bacterial. The fungal component increases directly as
system productivity increases.
The most productive soils are those with the greatest amount of organic matter
used by BENEFICIAL bacteria,
fungi, protozoa, nematodes and microarthropods to build soil structure. The
most productive soils in the
world are 100 to 1000 times more fungal than bacterial. There is more fungal
biomass present in an old
growth forest than there is biomass in trees! The most productive soils have
more bacteria than less
productive soils, but the fungi far outweigh bacteria in the most productive
systems.
What is the soil foodweb? The soil foodweb is the set of bacteria, fungi,
protozoa, nematodes,
microarthopods, earthworms, and other critters in soil, which use the litter
material dropped to the soil by
the plants and the roots and the root exudates released by the plants.
The exact composition of the foodweb changes at each stage of succession. You
need to know what your plants
require in terms of the ratio of fungi to bacteria in soil, protozoa and
nematodes, microarthropods, in order
to set up nutrient cycling and nutrient availability correct for the plant.
The benefits of having a healthy soil foodweb are: · Retention of nutrients
in the soil instead of
leaching (stop using fertilizers) · Prevention of erosion (soil aggregation
keeps things tied down,
slopes don’t slide) · Disease suppression and prevention (stop using
pesticides) · Decompose toxic
materials in your soil · Increase plant growth by having the proper plant
growth hormones made by the
biology in the soil · Build soil structure (reduce watering by 50% over the
course of 1 to 2 years,
increase water infiltration into the soil and reduce erosion because water moves
the soil instead of running
over the surface)
Compost is an excellent way to replace the life in your soil, but applying solid
material to large areas, or
transporting solids long distances from a source of GOOD aerobic compost can be
expensive. Compost tea
requires very little compost (15 - 20 pounds for make 500 gallons of tea in 24
hours) to make large amounts
of tea, and since the organisms grow (yes, fungi grow in the tea, if you make
conditions right). Fungi are
strict aerobes, and so if tea becomes anaerobic at all, fungi will be attacked
and killed by the anaerobic
bacteria.
What is the foliar foodweb? The foliar foodweb is the set of organisms, similar
to the soil foodweb, on the
foliage of your plant. The plant leaf, blossoms, stems, etc. release exudates,
just like the roots, to feed
these organisms and keep a protective layer around the plant so disease can’t
attack, and nutrients will be
cycled correctly for the plant.
Improving the activity of the biology on leaf surfaces increases the carbon
dioxide in the leaf surface
layer, which increases the length of time the plant stomates are open. This
increases the nutrient uptake
that can occur. Of course, in drought conditions, this doesn’t happen.
Compost tea replaces these organisms in the soil and on the foliage. Active
organisms are required in tea so
they will stick to leaf, branch, blossom and bark surfaces.
What is Compost Tea? A water extract of aerobic compost (can be thermal, vermi-
or static produced) that
contains the soluble nutrients, the bacteria, fungi, protozoa, and nematodes
which were in the compost.
All compost teas should be aerobic when applied or you run the risk of killing
the plant parts to which the
tea is applied. Anaerobic tea or compost will contain alcohol, phenols, organic
acids, and proteins that are
very toxic to plant tissue.
It is necessary to have the ENTIRE foodweb to gain ALL the potential benefits of
compost tea.
Bacteria in tea: · Compete with and inhibit a few disease-causing organisms
· Cover surfaces so
some of the bad guys can’t find food, can’t infect the plant surfaces, and
uptake of micronutrients is
enhanced · Certain bacterial species are especially desirable in certain
conditions because they
decompose pesticides, sequester heavy metals, help fungi remove thatch, improve
mycorrhizal colonization,
repel insects. · Certain bacterial species produce materials that kill
specific species of root-
feeding nematodes · Retain nutrients in their biomass · Improve soil
structure by building micro-
aggregates
Fungi in tea: · Compete with and inhibit most fungal disease-causing organisms ·
Cover surfaces so
most of the bad guys can’t find food, can’t infect the plant surfaces, and
uptake of micronutrients is
enhanced · Certain fungal species are especially desirable since they
attack maggots, aphids, plant-
sucking insects, caterpillars, potato beetle, mosquito larvae, etc. · Retain
nutrients in their biomass ·
Improve soil structure by building macro-aggregates
Protozoa in tea: · Consume bacteria and some fungi · Indicate
anaerobic conditions when ciliate
numbers are high · Release nitrogen, phosphorus, sulfur and other nutrients
in plant-available forms
Nematodes in tea: · Consume bacteria, fungi, protozoa and other nematodes. ·
Certain species of
nematodes are especially desirable, since they carry bacteria that attack wire
worm, root-grubs, maggots,
cranefly larvae, weevil larvae. · Other nematodes specifically prefer to
consume root-feeding nematodes"
.