Shake Up Your Soil
Many of us know that our soil isn't as good as we want it to
be. Some soils are extremely sandy and do not hold water at
all. Other soils are mostly clay and hold water all too
well. However, it can be maddeningly difficult to decipher
what exactly your soil is composed of that keeps it from
being your plant's dirt paradise. However, determining what
type of soil that you have is not only easy, it can be very
amusing. After all, for this experiment you get another
chance to dig in the dirt.
The soil in your yard is made up of three main components:
sand, silt, and clay. The ideal ratio of these three
components in your soil is 1:1:1, or about 33% of each; this
is called a loamy soil. It provides good drainage while
still has a good water-holding capacity. Knowing what
percentage of each component you have in your soil gives you
the information you need to amend your soil properly.
To determine the amount of sand, silt, and clay in your
soil, there is a simple test that you can do by just using
materials around your home. First, you will need a glass jar
with straight sides. A mason jar works really well, and make
sure you have the top to the jar. Second, you will need some
clean water. The third item on the list is a surfactant like
liquid dishwashing detergent. Lastly, you need some soil
from your yard. Try to remove all large rocks, pebbles, and
plant material from the soil.
Fill up the jar with water until it is about 1/2 to 3/4
full, then add one teaspoon of the detergent. Now, sprinkle
in the soil from your yard until the jar is almost full; you
need to leave a little space of air so the concoction will
mix well. Screw on the top and check to make sure it is
tightly sealed.
Now for the fun part. Shake the jar vigorously to mix
together the soil, water, and detergent. A good one to two
minutes should do it; your goal is to break up all the soil
chunks and mix them in with the soapy water. Once you think
it's well-mixed, set the jar down on a flat surface.
Sand is the heaviest particle in your soil, and it will
settle first. Most of the sand should sink to the bottom
within the first minute after you've stopped shaking the
jar. Once you think the sand is all settled, mark the jar
with a permanent marker where the top of the sand layer is.
The silt is the next heaviest particle, and should settle
during the next four hours. When it has settled, once again
mark the top of the silt layer with a waterproof pen. The
clay particles are the lightest, and should settle after 24
hours. Mark the top of the clay layer on the jar when it has
settled.
Once your soil layers are settled and marked, you can
analyze the thickness of the levels to see how much of each
component you have. Observe the layers and give each a
percentage based on it's size compared to the entire soil
sample. This number does not have to be exact, just make
sure that the three percentages add up to be 100%.
For example, your soil sample might look like it is 40%
sand, 40% silt, and 20% clay. This adds up to 100% soil. You
can use these three numbers to determine the texture of your
soil using a table called the Soil Texture Triangle (see
below).
The Soil Texture Triangle
http://www.turftamerinc.com/Images/soil_percent.jpg">
To use the Soil Texture Triangle, find the percentage number
of your three components on the table. To follow along with
our previous example of 40-40-20, first look at the 'percent
sand' section at the bottom of the triangle. 40% is a little
to the right of center. The 'percent silt' section is the
right side of the triangle, where 40% is just a little above
center. Lastly, the 'percent clay' section is on the left
side of the triangle, and 20% is near the bottom.
Follow along with your eyes or use your fingers to trace the
three lines coming from the percentage numbers until they
all intersect at a point. For our example, all three lines
intersect in the middle bottom of the triangle in the
colored section called 'loam.' This means that your soil has
a loamy texture, and will work quite well for growing plants
and turf.
Study the Soil Texture Triangle to see what different
combinations create different soil textures. There are
twelve main textures that your soil can have. It can range
from clay to sandy clay loam to silt, with a whole lot more
choices in between. By determining what type of soil texture
you have, you can then make any necessary adjustments to
create a good, loamy soil to support your plants.
