Healthy Soil Ecosystem Brochure part 1

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What is a Healthy Soil Ecosystem?
There is a whole ecosystem of life, both
microscopic and visible to the naked eye,
operating within healthy soil; it is the
universe of the underground. In fact, a
teaspoon of good soil contains 1 billion
invisible bacteria (of which there are 20,000 to
30,000 different species), several yards of
fungal hyphae, thousands of protozoa and a
couple dozen nematodes.
If this life is mostly microscopic, small and
often unseen how does it affect us as
humans? This soil ecosystem is actually vital
to our survival as humans because it is these
organisms and their daily interactions and
symbiotic relationships, with each other and
plants, which create the perfect balance of
conditions in the soil necessary to grow
thriving food crops and other plants.
How does this soil ecosystem
work?
Plants need a balance of proper soil
structure, water, nutrient availability,
nutrient cycling and natural defense systems
to really thrive. Plants use energy from
photosynthesis to secrete exudates (Chemicals
which are similar to pheromones in humans.
These exudates are made up of carbohydrates
and proteins) through their roots. These
exudates attract soil microorganisms such as
bacteria, fungi, nematodes and protozoa to the
plant’s roots. Microorganisms feed off of these
carbohydrates and proteins (exudates) and
exchange nutrients in the plant’s root zone in
return. In fact, a plant secretes certain exudates
to attract a certain amount and certain kinds of
soil organisms based on the nutrients it
requires. It is through these natural
relationships (formed over millions of years)
that plants and soil organisms create optimal
conditions for their survival such as:
 Optimal soil water retention and
drainage so plant roots and organisms
can get enough water without being
suffocated or rotting from too much
water
 Optimal soil aeration so plant roots
and living organisms can get enough
oxygen
 Soil strength: the pathways and
binding functions provided by soil
organisms through their movement in
the soil specifically strengthen top
layers of soil, increasing resilience
against compaction from heavy rain or
human activity atop.
 Plant available nutrients and
nutrient cycling. Any soil has all the
nutrients (potassium, nitrogen and
phosphorous) and micronutrients
(calcium, boron, iron, zinc) needed to
sustain plant life; however, these
nutrients are not in forms that plants
can use right away. Microorganism
activity converts the above nutrients
into forms the plants can use and in
the proper rates and amounts the
plants need.
 Nutrient Retention: certain soil
organisms immobilize (retain nutrients
in their bodies) nutrients. The only
time these nutrients are released is
when the above organisms die or are
eaten, and in the decay or digestion
process nutrients are released from
their bodies in plant available form.
This immobilization process prevents
nutrients from leaching out of the soil.
A brief note on negative effects caused
by chemical fertilizers
 Chemical fertilizers are able to put
nitrogen, phosphorous and potassium
into the soil in plant available form,
but these fertilizers cannot be inputted
in portion sizes and rates that plants
require, so the fertilizer is inputted all
at once and often leaches out of the
soil before properly helping the plant
while also poisoning ground water. In
fact, chemical applications of
phosphorous become unavailable to
plants in seconds.
 Important relationships between plant
roots and microorganisms will not
form if plants become reliant on
chemical fertilizers because plants can
get “free” and “easy” nutrients from
fertilizers and will therefore, bypass
the process of obtaining nutrients from
soil organisms.
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