soil pyramid chart
Another issue, in more
extreme slow-draining
cases, is anaerobic bacteria
breed and the wet soil
becomes toxic, causing root
rot diseases. This creates
a terminal situation for
whatever plants are located
there. Knowing the drainage
of the soil before planting
is critical when trying to
grow in poor soil.
Soil Amendments
Though water will continue
to penetrate after application
has stopped, slow-draining
soils will usually need 60 to 90
minutes of run time to sink to
the depth needed. These soils
also stay wet much longer.
Secondly, wet soil does not
allow for air or oxygen to get
to the roots for respiration to
occur. The technique to deal
with this is usually amending
the soil with sand in addition
to the organic matter needed.
Amending usually calls for
mixing the native soil with some
other material having a different
structure. When clay is high,
however, amending can bond
these two materials forming
an adobe-like soil that is still
problematic. When the clay
content is more than than 20 per
cent, it’s best to replace some or
all the native soil to reduce the
clay content. Even here we may
obtain a reasonably good soil
within the planting hole, but still
having this surrounded by poor
draining soil. This is much like
having a tub filled with sand —
it still won’t drain.
60
Maximum Yield
“A common issue
faced when growing
in outdoor soil is
the drainage rate.”
Sometimes there’s a layer
of clay soil that can be dug
through to create drainage,
yet often this is unknown
and the attempt to dig a
“stovepipe” through the clay
can be fruitless. In most of
these situations the best
option, while still being
able to plant successfully,
is to create a raised bed, or
at least a berm where the
planting is above the mean-
soil line and so will drain.
Materials like sand, compost,
coir, peat moss, perlite, or
vermiculite are among the
amendments available for
changing and improving
the soil condition. These
amendments not only help
control drainage but are
necessary for the microbial
soil life which is so essential
for plant health and vigor.
Organic matter in the soil
is key to sustaining soil
microbes. Once bacterial
or fungal life is introduced
to the soil, it is primarily
the organic matter that
feeds this life. The reactions
created when bacteria
feed on organic matter are
responsible for nutrient
precipitation where it then
becomes available for the
plant. These reactions also
produce acids that work
towards lowering soil pH.
Even with organics like this,
balance is the key. Too much
green organic matter is like
putting too many logs on
the fire and smothering the
flames. If, for some reason, it’s
necessary to add high levels
due to poor native soil, be
certain to use organic matter
that has completely finished
composting and contains low
levels of green material.