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  • From: "Tradingpost" <tradingpost@lobo.net>
  • To: livingontheland@lists.ibiblio.org
  • Subject: [Livingontheland] The Story Of Soil
  • Date: Tue, 27 Jul 2010 18:49:32 -0600



The Story Of Soil
http://www.countercurrents.org/avis270710.htm
By Rob Avis 27 July, 2010
VergePermaculture.ca

What is the difference between soil and dirt?

Soil is alive. Dirt is dead. A single teaspoon of soil can contain billions
of microscopic bacteria, fungi, protozoa and nematodes. A handful of the same
soil will contain numerous earthworms, arthropods, and other visible crawling
creatures. Healthy soil is a complex community of life and actually supports
the most biodiverse ecosystem on the planet.

Modern soil science is demonstrating that these billions of living organisms
are continuously at work, creating soil structure, producing nutrients and
building defence systems against disease. In fact, it has been shown that the
health of the soil community is key to the health of our plants, our food and
our bodies.

Why is it then, that much of the food from the conventional agricultural
system is grown in dirt? The plants grown in this lifeless soil are dependent
on fertilizer and biocide inputs, chemicals which further destroy water
quality, soil health and nutritional content.

How did we get here? How do we turn this around? This is the Story of Soil…

Turning and Ploughing Soil

It all started about 10,000 years ago when humans started ploughing the
fields in the experiment called agriculture. The settlers noticed that when
they ploughed the field their crops would grow faster. Based on this positive
feedback it was concluded that ploughing must be constructive and more fields
were turned. However, in actual fact the bacteria, fungi and arthropods in
the soil are essentially nutrient locked up in biology. For example, bacteria
is almost 90% nitrogen. Ploughing the soil was killing the life in the soil
resulting in an unregulated jolt of nutrient available to the surrounding
plants. Over time, with the death of all soil microbes, the soil is unable to
naturally support life and the farmer had to move to more fertile ground. The
agricultural pattern emerged: deforest, plough, irrigate, salinate,
desertify, move on.

How the Synthesis of Acid Changed the World

About one hundred and fifty years ago humans discovered how to synthesize
sulphuric acid. The synthesis of acid allowed for a major advance in
industrial agriculture: the ability to dissolve rock minerals into a
water-soluble form. This meant that macro-nutrients such as nitrogen (N),
potassium (P) and phosphorus (K) could be added to the soil in a form that
could be taken up by plants.

As acid was discovered at around the same time as petroleum, this meant the
advent of harder, faster and larger-scale ploughing with the use of water
soluble salt-based minerals. Again, what could be wrong with a system that
produces so much?

Plants and Their Roots

Plants have two main types of roots: tap roots and hair roots. Tap roots are
responsible for hydrating the plant, i.e. drinking water. Soil does not
freely feed or give minerals (such as calcium, magnesium, etc) to plants and
so in order to get minerals a plant must make a “trade” with the soil biota –
this is the primary function of the hair roots. Therefore the hair roots are
the mineral traders and create an environment around themselves called the
rhizosphere - a habitat for soil biota.

Through the process of photosynthesis plants produce exudates (sugars) and
commit up to fifty percent of these sugars to the action of feeding and
trading with the biology in the soil. When the plant needs a certain mineral,
say calcium, it offers exudates to the biota that can provide calcium. This
is a symbiotic process in which the plants support the biota and the biota
support the plant.

And so, if you plough soil and kill off the biota and soil microorganisms,
how does a plant get minerals? The industrial solution is to feed the
minerals to the tap roots, i.e. put water-soluble dissolved minerals in the
drinking water, otherwise known as fertilizer. The advent of nitrogen,
potassium and phosphorus fertilizer (NPK) meant that we did not need to rely
on a bank of soil biology to make our plants grow. We could add
macro-nutrients at whatever rate we desired and grow plants faster and
quicker than ever before – in increasingly lifeless soil.

Have you ever salted a slug? What happens? The salt creates a large osmotic
pressure on the creature's cell wall and results in death. This analogy can
be used to understand what happens to the soil biology when salt-based
fertilizer is used (note that all fertilizer is based in mineral salts). So
the salting of the land through broad-acre fertilization ensures that the
biology is completely dead. As long as we keep applying fertilizer there is
no chance for life to return.

Without life in the soil, no natural mineral exchange can occur. Also, with
plants being forced to drink mineral soup through the tap root, less energy
is devoted to developing an overall healthy root structure. Fertilizer has
become an addictive drug. It has eliminated the soil biota, replaced that
function in the ecosystem, and now must be continually applied. Whoever
controls the fertilizer market secured their market share the same way as the
cocaine dealer.

The Downward Spiral

By the late fifties farmers were using NPK at record levels, tractors were
highly advanced and the soils in the world were on a fast track to doom. The
use of mono-culture crops, heavy tilling, irrigation and fertilizer was
killing the soil and making our plants weak and addicted to chemicals.
Monocrops of these obese and sick plants became an all-you-can-eat buffet for
pests and the degraded and depleted soils a great opportunity for pioneer
species (i.e. weeds).

“No worries!” proclaimed the Chemical Companies, “we've got the solution for
that too”. Let's kill these pests and nasty weeds that are causing all the
problems – and thus pesticides and herbicides were born.

Without healthy soils to support beneficial fungal population the next
problem to emerge for farmers was fungal issues. The “next solution” - apply
fungicide!

We are now left with dead, acidic and salted soils that are only good for
holding up plants.

Weeds and What they Tell

Carbon is the building block of life. Any soil scientist, gardener or farmer
will tell you that a soil with no carbon is a dead soil. Carbon and nitrogen
like to bond together at a rate of 30:1 and most gardeners know that mixing
too much carbon into (like mulch or straw) will decrease available nitrogen.
The reverse is true as well and adding nitrogen (in the form of fertilizer)
actually reduces carbon levels in the soil. Without carbon, fungus has no
food source and dies. The soil collapses leading to hard packed dirt and
anaerobic conditions (no oxygen). What comes next are Nature's signs of a
sick system trying to heal itself: weeds, pests and erosion.

It has been proven that the weeds that grow on the surface of the soil are a
response to a condition in the soil. For example, pig weed and thistle grow
in soils high in nitrates (i.e. fields that have had a history of fertilizer
use), and bracken ferns and blady grass grow in soils deficient in potassium
(i.e. soils that have burned). Therefore, most of the agricultural weeds that
we spray with herbicides actually have an ecological function. Club root,
dandelion, knapweed, chickweed and amaranth all indicate too much nitrogen
and anaerobic conditions - they are trying to build the topsoil carbon levels.

Weeds such as these do not divert a lot of the photosynthesis energy into
soil biology relationships and instead they produce thousands of seeds and
lots of carbon - they are fast carbon pathways. As the carbon in the soil
increases, the soil is able to support fungal associates and bacterial
populations encouraging the next stage of succession and return to soil
health. Fast growing weeds and pest attacks are mechanisms in nature to
eliminate monospeciation and increase biodiversity. If we truly wanted to
stop the weeds and pests, the only real solution is to first understand why
they are there. Weeds give us clues as to how to repair the soil and how to
prescribe techniques to speed up the repair process. For example, if thistles
are trying to build soil so that biodiverse life can return to it, we can
speed up the soil-building process by adding the right plants and life back
into the soil.

Patterns Repeat Themselves

Instead of seeing the pattern that got us here in the first place we tend to
trust in the system that misunderstood from the beginning. The
countermeasures in industrial agricultural have all been based on too narrow
a definition of what is wrong. When a decision is made to cope with the
symptoms of the problem, second generation problems are created. It has now
come to the point where we've invented and hybridized plants to grow in
degraded soil / dirt and genetically modified our food to be tolerant of
pesticides, herbicides and fertilizer. However, the use of chemicals is not
just stopping the natural succession of the ecosystem, it is turning the
clock backward toward death or desert.

I find it particularly interesting that the soil & chemical Ag industry is
the same pattern as the human & pharmaceutical industry. Treat the symptoms.
Patent the “cures”. Profit from the lack of health. I also suspect that the
slow death of the healthy soil ecology over the last hundred years of
intensive agriculture could be directly correlated to the increase in
disease, illness and mineral deficiency in the human species.

There is an old saying from a farmer that I am particularly fond of: “I am
sick of growing things that die and killing things that want to live”. It is
amazing to me how much energy and money we spend in our quest to kill when
all nature wants to do is live. Imagine what the world would look like if we
invested the billions of dollars that currently go into killing weeds, pests,
and fungi on processes that encourage life, and work with rather than against
nature. The more you look at the current system the more you realize that our
quest for domination over the soil is perpetuating a system of scarcity. What
we need more than ever is a new paradigm to support a system of abundance and
life.

Lucky for us that new paradigm exists! It is a branch of soil science that is
called the Soil Foodweb. Paul Taylor of “Trust Nature” has been an organic
farmer for over 30 years and is one of many to show that the use of aerobic
compost and compost tea can turn dead degraded dirt into life-giving soil in
as little as three years. The cycle of biocides is being replaced with a
cycle of life. When we design properties to harvest water which fix the water
cycle and apply biology through compost the results are nothing short of
miraculous. Nature wants to come back, we just have to help her out a bit.
Best of all, permaculture gives us all of the design tools to make this a
reality.

If you are interested in more information on soil health, I highly recommend
the book: “Teaming with Microbes, A Gardener’s Guide to the Soil Food Web”,
Lowenfels & Lewis. The Soil Foodweb Organization is another great resource.

Attachment: Soil_food_webUSDA_0.jpg
Description: JPEG image



  • [Livingontheland] The Story Of Soil, Tradingpost, 07/27/2010

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