I know it's been said many times before
but I'd like to echo the claim that
compost is one of the best soil
amendments you will ever find
it's natural it's full of nutrients and
microbiology and you can make it at home
for free
now this video isn't about the process
of making compost but rather how you can
use compost and other decaying organic
matter to improve your soil over time
we've had a few problems with slow
draining soil in our garden and I
thought it may be because of a high
ratio of clay but I hadn't fully tested
our soil yet so I wasn't positive
I should have tested it a long time ago my
previous attempts to address this topic
have missed the mark considerably so my
goal with this video is to provide
detailed information that can help you
learn more about your own soil
everyone's soil is different and I can
only use our own as an example but I'm
positive that this information can have
a wide range of applications
For this video I teamed up with my friend and
fellow youtuber Jan and his channel
Small Garden Quest where he's dealing
with heavy clay soil in Slovenia he made
his own video where he thoroughly tested
three of the most common amendments for
clay soil: gypsum sand and compost along
with a control sample be sure to check
out his video to see the results of the
tests I'll link it in the description
below first let's look at the physical
properties of our soil I dug up a small
sample and added a little water to work
it into a ball then I rolled that into a
rod and performed a ribbon test it
cracked a bit but it still got to about
5 inches before falling off under its
own weight I may not have performed the
test exactly right
so I wanted to do a jar test as well
I  filled up a mason jar with soil from a
few different locations then added water
and shook it up for well over a minute
even after waiting a full 48 hours for
everything to settle some of the
particles were still suspended in the
water I had to finish making this video
so I couldn't wait any longer but the
results from this test
confused me a bit after comparing my
results to dozens of images from other
people's tests that I found online and
then calculating the separate layers I
was led to believe that we had 57
percent sand
39% silt and 3.6 percent clay that didn't
really match up with my experience of
working the soil by hand feeling how
smooth and sticky it is and performing
ribbon tests again I may have made some
mistakes performing this test as well
it's possible that this may be mostly
silt with a little sand and organic
matter on the bottom then heavy clay in
the middle and a very fine clay on top
the USDA soil survey website shows that
the soil in our neighborhood is
classified as a silty clay loam and that
actually matches better with my hands-on
experience working with our soil
I'll have to continue with further testing in
the future to get a more definite answer
so let's move on and take a look at clay
on its own to understand its pros and
cons as you would imagine clay soils
have very little aeration and become
compacted quite easily this means that
it can take a very long time for water
to drain through and in some cases the
water can hardly penetrate at all
however I would have to say that out of
the three soil particle categories of
clay silt and sand clay is probably the
most important when it comes to
gardening this is because it's partly
responsible for a soils CEC or cation
exchange capacity I'll just keep it
simple and say that the CEC is a measure
of the soils ability to hold and
exchange mineral nutrients that plants
need clay particles along with organic
matter have a negative charge essential
plant nutrients like potassium calcium
magnesium and others have a positive
charge so just like magnets they stick
to clay and organic matter so I fully
understand now why it was such a
terrible idea to try to remove clay from
our soil hoping to improve it and I
would never do anything like that again
any experienced gardener will recommend
that you test your soil before adding
any amendments and they're absolutely
right we live in Iowa and I found that
Iowa State University stopped doing
public soil testing a couple
years ago but they did provide a link to
a lab with several locations here in the
Midwestern u.s. so I contacted them and
requested a soil sample bag which they
supply for free I didn't have a soil
sample tool so I tried to figure out an
alternative with materials that I had at
home I took a length of electrical
conduit leftover from making our
trellises and I made a mark at six
inches
I used the mallet to drive it into the
soil and then a garden stake to push the
soil out into the sample bag this didn't
really work as well as I had hoped since
the garden stake didn't fit all nice and
snugly inside the conduit so I
eventually gave that up and just used a
trowel to finish filling the bag quickly
I sampled ten different locations mixed
it all together in the bag and mailed it
to the lab I chose their mid-level soil
health test for fifty-five dollars you
can definitely find cheaper soil tests
that measure just the basics like pH and
NPK but I decided to pay the higher
price to find out the levels of
micronutrients like calcium sodium
sulfur and much more and I'm really glad
I did because now I can give you a
couple of prime examples of exactly why
compost is so fantastic gypsum or
calcium sulfate is often recommended to
improve the texture of heavy clay soils
it's said to create aggregates with the
clay and thereby improve drainage though
this benefit is short-lived as the
gypsum breaks down into the soil in
sometimes just a matter of months but
let's take a look at our own soil say I
decided to add gypsum to improve its
structure gypsum will remove sodium and
replace it with calcium and as you can
see we don't really need that we already
have a high amount of calcium and very
little sodium adding gypsum would only
increase this difference and potentially
inhibit plants from taking up other
nutrients it's also been shown to
inhibit mycorrhizal associations from
forming between plant roots and soil
fungi we absolutely don't want that
because mycorrhizae helped to deliver
water and nutrients to the plants adding
gypsum would increase sulfur levels
which we do need but that's where
compost
to the rescue not only does compost
contains sulfur and many other essential
minerals it also has a negative charge
which can increase our soil's CEC value
remember that means it can hold more
nutrients 14.2 is apparently a decent
rating but we can definitely improve on
that so adding gypsum is probably not
the best option for our soil but what
about sand there are some claims that
adding sand to a clay soil will make
something like concrete that may be true
in some cases and not in others
there are some different opinions on
that again you can check out Jan's video
at the link in the description to see
how it turned out when he tested it but
sandy soils have much better aeration
because the larger particles create
pores between them and allow water to
flow through but they don't hold onto
nutrients the theory though is that
adding sand to your soil will provide
this benefit of better aeration but
let's take a look at the micro level and
see just what happens when you mix sand
into a clay soil if you only mix a small
amount of sand into the soil the
particles become so spread out from each
other the clay fills in the spaces
between them this doesn't improve
aeration at all in fact it can make it
even worse you would need to add a lot
of sand about 50% of the total volume to
increase the chances that particles
wound up close enough to each other to
create pore spaces this would not be a
cost-effective way to amend your soil
additionally sand particles have no
electrical charge and they can't hold on
to mineral nutrients so adding a whole
bunch of sand would significantly reduce
the CEC value of your soil so once again
compost is the answer it binds the soil
together forms aggregates creates air
pockets provides food for soil biology
and it actually has an even higher CEC
than clay it's pretty much the answer to
all of our problems at least if we're
talking about soil
we are talking about soil right so the
best thing you can do is to start making
your own compost I haven't made a
complete video about that yet but I
probably will once we have a finished
product that I can show you remember to
check out small garden quest for videos
on composting saving money square foot
gardening and much more thank you for
watching this video if it was helpful to
you please give it a thumbs up and share
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see you next time
