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THE DIRT ON SOILS!
Soil is the outermost layer of our planet that all
life depends upon. Five tons of topsoil spread over
an acre is as thin as a dime. It takes natural
processes at least 500 years to form 1 inch of
topsoil. Over 70,000 types of soils have been
identified in the United States. Five to ten tons of
animal life can live in an acre of healthy soil.
- Healthy Garden loam (Topsoil) is composed of
sand, silt, clay, humus (at least 5%),
macro-nutrients, trace minerals, micro-nutrients,
and microorganisms.
- Organic matter (i.e. compost) in the top 6
inches of the soil provides:
- growth-promoting hormones
- toxins and antibiotics
- mycorrhizae fungi
- nematode destroying fungi
- unlocks minerals
- nitrogen fixing microorganisms
- increase moisture holding capacity
- sticky substances that bind particles into
aggregates
- increases air space, drainage and
aeration
- acts as a buffer against chemicals and
high/low soil pH
- releases nutrients over a long period of
time
- maintains the soil base exchange capacity
- gives soil good tilth--easy to work and till,
wet or dry
- helps recycle waste products and prevents
erosion
- Compost is an excellent soil amendment that
also acts as a slow release fertilizer containing
nitrogen, phosphorus, potassium, trace minerals,
microelements, humic acids, fulmic acids, and
other needed nutrients (vitamins, enzymes,
microorganisms, etc.).
- Healthy soils contains the following
microorganisms: bacteria, fungi, actinomycetes,
algae, protozoa, yeasts, nematodes, germs, and
other tiny critters. Over 13,000 different
organisms have been identified that live in the
soil.
- Microorganisms feed on organic matter in the
soil and form glue like material called
polysaccharides. These complex sugars are what
binds or welds individual soil particles together
creating larger aggregates. This process gives
soil its wonderful soft crumbly texture and helps
prevent erosion.
- "A healthy soil has a constantly
changing, but always active population of
microbes. There are approximately 900,000,000
(nine hundred billion) of these lifeforms in
every one pound of soil." H. Garrett,
Harmony With The Environment, Acres USA, June
1993
- Humus is the dark brown to black substance
that is the secret key to healthy soil. It is
nearly insoluble and contains about 30% each of
lignin, protein, and complex sugars. It contains
3-5% Nitrogen and 55-60% Carbon. Humus is the
source of food and energy for microorganisms
development and is the stage of decomposition
that provides food from the soil to plants in the
form of slow release nitrogen, phosphorus and
sulphur.
- Mulch is the best way to add organic material
to your soil. Compost is the best mulch for this
purpose.
- There are 930 billion microorganisms in each
one pound of soil under turf. There are about 70
pounds of them living and working in each 1,000
square feet of root zone. Many of these organisms
are very short-lived, so the turnover is rapid.
One Hundred pounds of dead microorganisms will
contain close to ten pounds of nitrogen, five
pounds of phosphate, 2 pounds of potassium, one
half pound of calcium oxide, one half pound of
magnesium oxide, and one third pound of sulfate.
With 70 pounds of these creatures per 1000 square
feet of root zone, the poundage adds up to enough
per acre for excellent crop production. Elliot C.
Roberts, The Lawn Institute.
- Synthetic chemical fertilizers destroy soils.
As soils are being destroyed, plants become
weaker and actually attract insects, diseases and
weeds. When we spray fungicides, insecticides and
herbicides we accelerate the destruction of the
soil. Humus (organic matter) is literally burned
out of the soil reducing (if not eliminating) the
microorganisms that take nitrogen from the air
and make it available for plants. This requires
larger amounts of nitrogen based chemical
fertilizer to get plants (crops) to grow and the
cycle continues. Additionally, soil structure is
destroyed greatly increasing erosion and the
leachates in the runoff pollutes streams, ponds,
groundwater, etc.
- Organic matter also stores mineral nutrients
such as calcium, magnesium, potassium and many
others. It keeps these valuable nutrients from
washing out of the soil, and makes them more
available to the plant (Medina Magazine).
- According to Dr. E. Ingham, Soil Biologist,
Oregon State University, a teaspoon of healthy
soil is teeming with:
- 100 million or so individual bacteria
- 50 to 150 meters of fungal threads
- 10,000 to 100,000 protozoa
- 5 to 500 beneficial nematodes.
- Thiamin (vitamin B1, aneurin) is a naturally
occurring compound present in soils, water, plant
and animal tissue, which is required for
microbial and plant growth. Thiamin is known to
affect both root and plant growth. A reduction of
organic matter in soils reduces the CEC ratio
which leads to reduced Fe (iron) and Al
(aluminum) availability on the surface of clay
particles which may cause a reduction in thiamin
absorption. Organic matter also helps bind
thiamin with increasing pH. The absorption of
thiamin is closely related to the stoichiometric
exchange of the Ca++ (calcium ion) which suggest
that absorption of Thiamin occurs by an exchange
mechanism. Soil Science Society of America
Journal, Nov./Dec. 1994, p.1829.
- A healthy soil will have an abundant
earthworm population which is busily at work
increasing the soils fertility.
- Soil pH is constantly changing. Large changes
can occur naturally with 48 hours. Soil
compaction can raise the pH level even moisture
can change the pH.
- A recent study found that soil compaction
reduces crop yields and plants grown in compacted
soils had greatly increased insect damage.
Journal of the American Society for Horticultural
Science, 120(6):956-963. 1995.
- Soils with lots of organic matter hold
minerals better. A recent study of agricultural
soils found that total soil sulfur decreased in
all treatments where no organic material was
added. However, of the organic amendments 26-54%
of the sulfur remained in the soil with a
half-life of 24-38 years. Soil Science Society of
America Journal, p.174-178, Vol. 60 #1,
January-February 1996.
- Synthetic soils (generally light weight
potting or bedding media) are often soil-less,
this means they looses water very quickly, they
do not retain nutrients, do not support
beneficial microbes or other beneficial organisms
such as earthworms. Hence a lot of disease and
insect problems are the result.
- In Texas it is estimated that we lose up to
4,000 pounds of humus per acre each year due to
natural soil breakdown in high temperatures. Neil
Sperry's Gardens, Nov.-Dec. 1996.
Note 1: Along the Gulf Coast with higher
moisture levels, humus lose is even
greater.
Note 2: Freshly organic matter contains 1-2%
humus or less. It is the action of microbes and
earthworms that convert organic matter into
humus. Depending on the form of organic matter,
it could take 400 cubic yards per acre each
year to replace what is lost.
- One of the biggest problems we have with our
soils is the loss of trace and micro nutrients
(i.e. minerals). The growth and health of plants
is limited by the least available nutrient. As
plants grow the minerals are used up to form
plant tissue from stalks and leaves to the fruits
and vegetables we eat. If the minerals needed for
good health are not in the soil then they are not
in our food (plant or animal) and our health
suffers. To restore soil health we must add back
mineral dusts (lava, granite, basalt, etc.) to
the soil. The microbes will release the minerals
for plants to use.
- Research has recently identified a physical
property associated with good soil, the
Paramagnetic force as it is often incorrectly
called. After studying soils from around the
world he has found that the healthiest soils with
best plant growth and highest crop yields have
high paramagnetic values while poor soils have
low values. How these low level energy fields
affect plant growth is not fully understood but
the direct correlation with plant growth is
confirmed. Volcanic rocks (lave, granite,
basalts, etc.) generally have high paramagnetic
values hence mineral dusts form these rocks have
an additional value. Paramagnetism -
Rediscovering Nature's Secret Force of
Growth, by Philip Callahan, Ph.D., 1995.
- Research from Europe has found than bacteria
that lives in the guts of grazing animals like
cows and horses produce the vitamin B12 and extra
B12 is excreted in the manure. When manure is
used as fertilizer at a rate of 10 grams per
1,000 grams of soil the plants grown in manure
fertilized soil had 2-3 times the B12 as plain
soil plants. Plants have the ability to absorb
whole vitamins directly from the soil. Plant and
Soil Journal.
- When Penn State University tested over 50
samples of alleged sterile potting mix in sealed
plastic bags they found all the bags had disease
spores. A sterile mix is a biological vacuum
waiting to be filled.
- Researchers at the USDA's Soil Microbial
Systems Lab have discovered a new protein named
glomalin, which is produced by fungi that helps
glue soil particles together making it easier for
air and water to move through the soil. The
improved circulation also creates a healthier
environment for plants and beneficial
microorganisms. Tests have shown that no-tilled
corn plots were more stable and contained more
glomalin than tilled plots. Soils with the well
stabilized structure were far less prone to
erosion from wind or water. BioCycle, December
1997.
- USDA scientists have found a fungal protein
(glomalin from the Glomales fungi), that binds
soil particles together. They also found that
there is less of this protein in tilled soils
than untilled soils. Studies of various soils
have shown that glomalin glues soil particles
together into beneficial aggregates with some
soils having up to 2% by weight of this protein.
These fungi are found around the world growing on
root hairs of plants. The American Gardener,
March/April 1998.
DEFINITIONS:
Clays: + smallest of soil particles, high
nutrient and water retention capability, helps
bond larger soil particles together
- high % of clay can make soil difficult to
work, shrink and swell with water content,
slippery when wet, hard when dry, poor
aeration.
Silts: + between clay and sand in size
and properties, important in loam soils
- not important by themselves
Sands: + coarsest
of all soil particles, well aerated, drains
rapidly, ideal for root growth
- moisture and nutrient retention are
poor.
Loams: (1) soil that contains equal amounts
of clays, silt, and sand, plus some organic
matter, the ideal garden soil
(2) Example a 40 % sand, 40% silt, and 20% clay
is considered a loamSandy loam: 10% clay, 65%
sand, 25% silt
Silt loam: 60% silt, 20% clay, 20% sand
Clay soil: any soil over 55% clay
Coarse sand: often called sharp sand or
builders sand.
Small gravel: often called bird gravel or pea
gravel.
SIMPLE SOIL TESTS
1: Take a sample of soil 8-12
inches deep and place into a jar 75% full of
water, and shake vigorously for 10-15 minutes
and all soil chunks are dissolved. Let jar set
for several days (until water clear) and you
will see different layers of gravel then sand
silt and clay. The thickness of each layer
related to total thickness gives the amount of
each.
2: Get a handful of soil and
wet it a little with water. Squeeze your hand
into a fist and then release. All but the most
sandy soil will form a ball or clump with
distinct finger marks, if you can make a rope
with the ball then a good mix of sand silt and
clay, if you can flatten the rope into a ribbon
without breaking it has a high clay content
3: Rub a small amount of soil
between thumb and forefinger:
- If it feels gritty then the soil is
sandy.
- If it feels like moist flour or talcum powder
the its silty.
- if it feels slippery and moldable or sticky
then it contains a lot of clay.
4: Sieve analysis (by weight
or volume), take a soil sample and dry in a
oven at low heat, or in the sun, then pass
through sieves and measure the amount of soil
in each size category.
USEFUL REFERENCES:
A non-technical overview of soils:
Start With The Soil, Grace Gershuny, Rodale
Press, Emmaus, Pennsylvania, Copyright 1993,
ISBN 0-87596-567-9.
The Dirt Doctor's Guide to Organic
Gardening, J. Howard Garrett,, University of
Texas Press, Copyright 1995, 0-292-72780-1.
The Rodale Book Of COMPOSTING, Deborah L.
Martin and Grace Gershuny, Editors Rodale
Press, Emmaus, Pennsylvania, Copyright 1992,
ISBN 0-87857-990-7.
A semi-technical overview of soils:
An Acres U.S.A. Primer, by Walters and Fenzau,
published by Acres U.S.A., Copyright 1992,
ISBN: 0-911311-37-8A technical introduction to
soils:
Introduction To Soil Physics, by Daniel Hillel,
published by Academic Press, Inc., Copyright
1982, ISBN: 0-12-348520-7
Paramagnetism - Rediscovering Nature's
Secret Force of Growth, by Philip Callahan,
Ph.D., published by Acres U.S.A. Press,
Copyright 1995, ISBN: 0-911311-49-1
ORGANIC Soil Conditioning, William R. Jackson,
PhD, Copyright 1993, Jackson Research Center,
ISBN 0-9635741-0-8
Soil Testing Laboratories:
Texas Plant and Soil Lab (from Acres, USA)
Route 7, Box 213Y
Edinburg, TX 78539
Peaceful Valley Farm Supply (from Organic
Gardening Magazine)
P.O. Box 2209
Grass Valley, CA 95945 (916) 272-4769
Timberleaf (from The Dirt Doctor's Guide To
Organic Gardening)
5569 State Street
Albany, OH 45710
Tiberleaf Soil Testing Services (from Organic
Gardening Magazine)
26489 Ynez Rd., Suite C-197
Temecula, CA 92591 (909) 677-7510
Wallace Laboratories (from Organic Gardening
Magazine)
365 Coral Circle
El Segundo, CA 90245 (310) 615-0116
Extension Soil, Water, and Forage Testing
Laboratory
Texas A&M University- Soil and Crop
Sciences
College Station, Texas 77843-2474 (409)
845-4816
Stephen F. Austin Soil Lab. (409) 468-4500
Terry Bell - manager, or Gene Bickerstaff
Soil and Plant Laboratory (from Composting
Council)
352 Mathew Street
Santa Clara, CA 95050 (408) 727-5125 (James
West)
Soil Control Lab (from Composting Council)
42 Hanger Way
Watsonville, CA 95076 (408) 724-5422 (Frank
Shields)
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