SOIL - INDOORS
- Discuss the importance of soil in our lives.
- Examine closely what soil is made of.
- Give students an opportunity to familiarize themselves with
an essential element that is often feared or looked down upon.
A children's book about soil with good pictures.
- "Life in a Bucket of Soil" by Alvin Silverstein and Virginia Silverstein
- "A Handful of Dirt" by Raymend Bial
- "Soil" by Christin Ditchfield
- finished compost
- unfinished compost
- 5 or more bowls
- 5 or more index cards
- hand lenses - preferably enough for two students to share one
- jar, water, spoon
- Put soil ingredients out in separate bowls and label each bowl with a different number
- If you have a large group, you may want to have two bowls for each ingredient (those could be labeled
with the same number or letter), especially for the compost, since the children will all want to look at it
very closely because of the living creatures it contains.
- soil is what plants grow in
- Our lives depend on the plants that grow in soil. All our food comes from plants that grow in soil;
animals that we eat need to eat plants to live, so we wouldn't have any food if there weren't soil.
- Dirt is a negative word for soil. We see it as "dirty."
- Soil is made out of organic and inorganic materials.
- An organic material is something that was once living, or comes from something that was living.
For example, a banana peel, or dead leavesb or a dead insect or animal.
- Inorganic materials are those that were never alive.
- Rocks, sand, gravel, clay
- If anyone says plastic, metal, or glass, explain that these are inorganic, but they are man-made,
not natural, so not an ingredient in soil.
Discuss; show pictures from book, or read short passages about soil, its importance to our lives,
and what it is made of.
closely) each ingredient, and in their notebooks, describe each one, listing it by its number or letter.
They can try to guess what it is.
Hand out the finished and unfinished compost and have them do the same thing (describe in their notebooks).
- The compost is made from organic matter, not from minerals, or rocks
Go over each ingredient (tell them what it is), and talk about how students described each one.
In front of the students, take a few spoonfuls of each ingredient (minus the unfinished compost)
and put it in a jar. Add water, and mix.
- Will all the ingredients settle to the bottom at the same time?
Accept lots of answers here, since they are predicting something - you want to let them guess.
Also, see Background Information
Students can draw a picture predicting what the jar will look like, if left untouched, after 3 days.
Soil is as essential to life on Earth as water, air, and the sun's energy. Our lives depend on the plants that grow
in soil. Soil is made up of organic and inorganic materials. The word organic refers to any material that comes
from something that was once living. For example, a dead insect or animal is organic, and so are dead tree leaves,
and a banana peel. Rocks, plastic, and metal are not organic. (We are NOT using the word organic to describe how
foods are grown). The inorganic materials in soil all come from rocks that have been worn down to different sized
particles, by the weather, over thousands of years. These different sized particles are classified as clay, silt,
and sand - clay being the smallest particle and sand the biggest. The organic materials in soil come from all the
living things, and parts of living things (leaves, fruit, roots) that get incorporated into it. This includes bacteria
and other microorganisms, which are not visible to the naked eye. A handful of soil is teeming with life!
This activity involves looking closely at the different components of soil. Since many of these components are not
readily available you may need to improvise. It is important for students to see the difference between organic
and inorganic ingredients. We used gravel because it is what sand, silt, and clay come from (sand and gravel can
be found in gardening stores, while silt is not readily found). For clay we bought a skin-cleansing product,
which is made of pure clay. We also brought in unfinished, as well as finished compost, so students can see
the ingredients that later become what looks like plain soil (but is really just organic matter). For these supplies
you may need to ask around and find someone who makes compost (community gardens are a good place).
Because compost has lots of living organisms in it, some of which are visible, this will fascinate children.
Leave time for students to examine these living creatures.
In the experiment at the end, the ingredients should settle in visible layers because of the different sizes
and densities of the particles of each ingredient.