It's a Dirty Job! But K/1 Will Do It!
by Theresa Farris
September 17, 2009
SVCA students are
stripping the gardens and removing old dirt to be replaced with a
more nutrient rich soil.
Soil has three main kinds of different sized particles: sand, silt
and clay.
Students felt sugar and salt to represent particles of sand. Flour
represented silt. And a mixture of flour and water represented clay
particles. This was a perfect time to identify the main ingredients
in the soil that will be removed.
We knew from our research that plants grow poorly in soil
containing too much sand because it dries out too quickly and
doesn’t allow roots to get enough water. Plants also grow poorly in
soil with too much clay because it keeps the soil too wet. Clay is
the fine particles that clump together and become sticky.
We discovered the best soil type is a mixture of all of these
types, but with only a small amount of clay.
We were curious about the texture of our soil. What better way to
find out than to make a mud pie.
We took a soil sample from our garden and mixed it with just enough
water
to make it stick together. If it crumbles and fails to keep its
shape it is a sandy texture. If it is sticky and stays the shape it
is squeezed into it is a clay-textured soil. If the soil is loose
and clumps together but is not sticky it is called
loam.
The texture of the soil in our sunflower garden made a perfect mud ball. K/1 decided that our sunflower garden was made up of mostly clay particles.
The soil in our butterfly garden held its shape but it was loose and not sticky.
We also tried the Shake, Rattle and Roll experiment to identify the amount and type of soil particles in our samples.
Each student had a small jar which they filled half full with a sample of soil from the sunflower garden and the rest of the way with water. Students had to shake the jar until the larger clumps were broken apart and then let it sit for a minute. Sand would be the heaviest particles and would sink more quickly to the bottom. After one minute we looked at the jars and did not notice any settling of sand particles on the bottom of the jar. After 24 hours without moving the jar we again observed no real separation of layers. We determined from this observation that our sunflower garden soil was made up of mostly clay particles.
We decided we should test the soil in our butterfly garden to determine its mixture of particles. After gathering a soil sample and mixing with water we noticed a definite layer of sand particles on the bottom within a minute. After 24 hours our soil had settled into different layers of particles. This experiment helped us to see that the soil in the butterfly garden was a better soil then the soil from the sunflower garden. We also noticed material floating on the water surface from the soil sample from the butterfly garden. Our Junior Master Gardeners Handbook referred this material to be organic matter, which contains nutrients and makes any kind of soil texture better.
