ello again fellow Earthlings. Yes, we're
about to embark on another voyage into the undersoil world of Jacques Curly-eau.
This adventure takes us into the mysterious realm of the Natural Gardener.
We will be looking at the soils that these gardeners cultivate and make
observations on the peculiar behaviors of the creatures known as Organic
Gardener...
O.K. I'm sorry, but I couldn't resist
it any longer. I have been itching to do that for months, and now that the
itch is scratched we can discuss this week's topic.
One of the most often discussed gardening
subjects among gardeners is the quality of the soils that we are stuck with.
Our soils can range from perfect black loam to pretty funky in some areas,
particularly in areas where houses have been constructed on cut or filled
soils that have been mechanically worked and transported for various development
purposes. These soils are not suited to sustain healthy plant growth for
several reasons, one being that the last time these soils saw the light
of day dinosaurs probably roamed the earth. These soils are also mechanically
compacted for purposes of stability making them a little on the slow side
when it comes to drainage and percolation of water. So it is the new homeowner
(you) that is tasked with building a suitable topsoil from this existing
material. Not to worry! This discussion is going to be about soil building
techniques for new and existing gardens.
Many of you have been informed at
one time or another that you have poor soils. Duh! And then, almost in the
same breath, someone -- an expert, of course -- has told you that in order
to grow that garden that you've always wanted you'll need to get rid of
that poor soil and put in anywhere from 12" to 36" of new "topsoil."
The next time you hear this I have a suggestion: RUN AWAY!!! Unless the
soil at your garden site is contaminated with toxic substances, there is
nothing wrong with your soil that a little time and patience combined with
a minimum of work cannot cure. Removing soil is labor intensive and transportation
of dirt can be costly.
But the main reason not to trade
dirt is a little thing called soil interface. This is a condition that occurs
when soils of different textures are put into the same space. If you made
a bowl out of modeling clay, filled it with sand and then filled the bowl
with water, what would you get? You're right: you get a bowl of wet sand.
That is exactly what happens when a layer of a porous soil is put on top
of a non porous soil. Then a whole new set of problems begins, including
but not limited to oversaturation of the imported material.
Our soils are some of the best base
materials for building a good garden soil. In many areas, we have heavy
clay-like soils that hold water very well. This can be a good thing, and
it is really simple to build from this mucky stuff. Those of you with sandy
soils are cursed with a very sandy material that drains away precious moisture
too quickly. But this can also be resolved and a soil with good moisture
retention capacity can be built from this material.
HOW, DON?
I'm glad you asked. But first some
science...
Once you get past all of the intellectual
explanations, soil can be described as a complex natural material made from
pulverized rocks and organic materials that provide nutrients, moisture
and an anchorage for terrestrial or land plants. Soil is made of four basic
components: mineral materials, organic matter, air and water. These four
components are combined in different amounts in different soils, with different
levels of moisture. As a rule, a good soil is any area with the ideal moisture
content of equal parts solid and pore space. The pore space is then equally
divided by air and water. The optimum amount of organic material is between
5 and 7 percent of the solid matter. That is not too daunting a task to
achieve. I'll tell you how.
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