The dirty secrets beneath organic
gardening: Higher yields, less fertilizer when soil in
tip-top shape
Barbara Kinnie
The Calgary Herald
June 18, 2004
There have been some exciting new
developments in recent years in our understanding of
soil health -- the dirt beneath organic gardening.
Much of this is based on Dr. Elaine
Ingham's pioneering work in the developing science of
the soil food web.
Associate professor at Southern Cross
University in Australia, Ingham is also president of
Soil Foodweb Inc. (SFI) in Oregon. Her company analyses
soil samples, identifies which organisms are missing or
out of balance, and recommends the remedy. Her work is
revolutionizing the understanding of soil ecology and
saving farmers millions of dollars in the process.
Ingham's work is based on creating a
favourable environment for plants by acknowledging
healthy soil is alive with biological diversity.
Amazingly, there are up to 40,000 species of beneficial
bacteria, 20,000 species of beneficial soil fungi,
thousands of species of protozoa, nematodes and
micro-arthropods in one teaspoon of living soil or good
compost. They are all part of the "soil
foodweb" and are necessary ingredients for soil to
be "healthy." Her research confirms a direct
relationship between the health and productivity of soil
and the health and productivity of plants.
Projects, such as the strawberry
fields in California's Salinas Valley, have earned
Ingham praise for her soil reclamation work. She
successfully increased productivity by returning dead
soil to top health in six months, saving
farmers substantial money in the process.
She achieved higher yields than with
chemical practices, eliminating fertilizer and pesticide
use. And this soil expert can boast equally dramatic
results that include saving palm trees at high-profile
beach resorts and large banana plantations.
To understand the impact humans have
on the soil foodweb, one must first be aware of the
vicious cycle of "drug" dependency we have
created.
According to Ingham, the use of
chemical fertilizers starts this cycle for a gardener or
farmer. Fertilizers, which are salt based, kill living
organisms in the soil. Without these beneficial
organisms, soil tends to compact. This makes it harder
for roots, water and air to penetrate.
Plants have a hard time growing and
become more susceptible to insects and weeds, which tend
to favour this unhealthy environment. So pesticides are
used in an attempt to destroy these pests, further
depleting the soil.
More fertilizer is then required.
So how do we "fix" our soil
to make it healthy and full of life? Ingham's answer is
to have your soil analysed by a Soil Foodweb lab and use
compost or compost tea to replace
what's missing. Spraying compost tea on plants coats
them with a multitude of beneficial bacteria, fungi,
protozoa and nematodes. Once on
the leaves, compost tea suppresses disease by crowding
out micro-organisms that aren't beneficial. It also
causes antibiotic reactions
against diseases.
We're not talking about just any
compost tea. Though brewing compost tea is
relatively simple, each element of the process is
critical. Ingham says you must
have good compost, an aerobic system and proper
nutrients.
Typically, a "tea set"
includes a brewing container, a pump to circulate and
oxygenate the water and a supply of nutrients. She also
emphasizes that good compost meets SFI standards, which
go beyond current federal and provincial
standards.
In Calgary, Ted Leischner has been
working and training with Ingham for fours years and has
recently established Soil Foodweb Canada.
"Our focus must shift from a
chemical 'ingredient' approach to an approach of
caring for the health of life around the roots of
plants," Leischner says.
Soil Foodweb Canada provides lab
testing, consultation, inexpensive compost
tea brewers and workshops.
Leischner reports that growers using
the soil foodweb management approach are reporting a 20
to 100 per cent reduction in use of chemicals, up to 95
per cent reduction in fertilizer use, 30 to 70 per cent
reduction in water consumption and increased crop yield.
The success of the soil foodweb can
easily translate to lawns, our largest urban
"crop." As Leischner has learned, "Since
most pest, weed and disease problems
can be traced back to unhealthy soil biology, the
solution is simple -- put the
biology back."
Compost tea just might be a key to
help us stop the cycle of pesticide and fertilizer
dependency we have created and move toward organic
gardening.
Barbara Kinnie has practised organic
gardening for over three decades and has
an interest in community, environmental and social
justice issues. She is chairwoman
of the Chinook Group of the Sierra Club of Canada.
-- This is the second in a four-part
series on natural gardening.
© The Calgary Herald
2004
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