Don’t Get in the Way of the “Good
Little Soil Bugs”
The more I learn
about how soil and worms and fungi and bacteria and plants interact,
and how
their underground “systems” work,
the more I realize how mistaken we are about so many things. Our intentions
are good - we’re following prevailing soil chemistry advice given
in textbooks, articles, and by crop advisors - but
much of what we do for (or to) our plants and crops
is horribly wrong.
To understand the problems, first consider the natural
cycle of plant-soil-microbial relationships
which have evolved over millions of years )greatly, greatly,
simplified).
- 1. Leaf litter,
dead plants, bird and animal droppings
fall to the ground.
- Decomposing
fungi and bacteria “digest” the
fallen material.
- Earthworms
feed on the decomposed material and then transport
it underground.
- Other types
of fungi and bacteria feed on
the earthworm castings, further digesting
it.
- The bacteria
produce nitrogen and digest
minerals into forms
plants can use.
- A plant seed
sprouts or new root growth occurs in the biologically-active
soil.
- Mycorrhizal
fungi attach
to the roots
and send millions of root-threads
out into the
soil.
- The plant
extends its
leaves up
into the sunlight, and performs
photosynthesis.
- Mycorrhizal
fungi and bacteria
feed on root exudates
generated
by photosynthesis.
- In return,
the fungi
forages
for whatever nutrients
the plant
requires for full health.
- The
plant
thrives aboveground with these
symbiotic
actions
going on underground.
- Leaves
drop
and/or
annual plants
die
and we go back to Step
#1.
The
closer we
can replicate
the above
cycle, the
better our
crops and
plants perform.
It’s
difficult,
and
I
would
even
say
impossible,
to
improve
on
it.
It
seems
that
our
goal
should
be
to
figure
out
how
to
work
WITH
the
established
method
instead
of
trying
to
take
over
the
complex
soil
functions
ourselves.
But
aren’t we helping the plants when we “feed” them?
Well, not when we drench the soil with immediate-acting
fertilizers, synthetic or organic. Small amounts of
gradual-release broad-spectrum fertilizers and minerals
can offset the leaf litter
(crops) that we remove
from the field, but whenever possible the crop residue
should be allowed to remain in place.
Are
we helping
when we
turn over
the crop
residue by
plowing it
under? Well,
a no-till
or limited-till
program will
keep the
underground biological
communities from
being disrupted.
A rototilling
is the
equivalent of
a powerful
hurricane leveling
a human
city. There
are impressive
results being
reported from
no-till agricultural
studies and
I expect
many more
farmers and
gardeners will
adopt this
practice.
The “little soil bugs”, if encouraged to develop into
large populations, will keep the soil fluffed-up for good
aeration, will provide nutrients (in ideal proportions)
for plants, and will protect the roots
from pathogens. They will happily do all this work
for free and will not contaminate our water supplies.
A
side note
on “Organic” additives: From my biological perspective,
the “nature=good,” “manmade=bad” orientation
is an imperfect way to judge materials. It does have
the general benefit of prohibiting the most harmful
fertilizers, such as high analysis fast-acting
synthetics (i.e., 20-20-10) which can be lethal to
mycorrhizal fungi, but it gives the impression that
all natural materials are OK. In fact,
a drench of liquid fish can disrupt the soil system
far more than applying dry pelleted fish. A slow continuous
supply of the broadest possible
array of nutrients is the feeding objective for bio-growers.
For
good reading on
this subject, the
March/April
issue of
The American Gardener
(the
magazine of the
American
Horticultural Society)
has an
article entitled “Fertile Ground.” One quote
from a gardening writer: “I believe the biology of the soil creates
the chemistry. It is only when the biology is killed off, as it is with
salt-based fertilizers, pesticides, tilling, etc., that the chemistry
takes over.” I say Amen!
The
June issue
of Mother
Earth News
will also
have an
excellent article
on mycorrhizal
fungi written
by Doreen
Howard, who
has considerable
first-hand knowledge
of biological
inoculants.
Both
articles are
geared toward
home garden
issues, but
the overall
descriptions of
natural soil
systems are
certainly worthy
of study
by commercial
growers, landscapers,
plant researchers,
and government
officals concerned
about agriculture
and/or environmental
issues.
Good
growing, my
friends,
Don
Chapman
President,
BioOrganics, Inc.
www.bio-organics.com
May,
2003
|