Sprout and Grow Window and RootVue Farm: These allow students to actually see roots
growing beneath the soil. Available at teacherdirect.com
Background for Teachers
This activity is set up to do demonstrations and experiences with
the whole class doing them together. You need to break this activity
up and do one section each day rather than trying to do it all at once.
You can also set this activity up into centers and have the students
rotate through them with an aide or volunteer helping with each one.
There are a number of things that need to be prepared ahead of
time for this activity
Assessment will be ongoing throughout the activity. Use the Red
Card/Green Card: Stop Me If I'm Wrong assessment strategy. Give
each student a red card and a green card. After each section present
statements to the students. If your statement is true, they show the
green card. If you make a false statement the students need to STOP
you by showing their red cards. They then need to decide what was
false about the statement and correct it so it becomes a true statement.
They then show their green cards again and you can continue.
At the end of this activity students should know the following:
- Rock is the parent material of soil. Rock is the source of the
inorganic (nonliving) materials found in soils. The rock is
broken down into sediments (small pieces of rock and minerals)
through the process of weathering. These sediments are a
component of soil.
- Most soils are formed from sediments that have been moved by
erosion-blown by winds, moved by water or glaciers. (Teacher
information: Fast moving water leaves behind gravel and sand.
Slow moving water and lakes leave behind fine textured clay
and silt when sediments in water settle.)
- Different types of sediment make different types of soil. Most
common soils are a mixture of these three types.
Sand: Large, gritty particles (Feels like sugar)
Silt: Smaller, smooth particles (Feels like flour)
Clay: Tiny particles, sticky when wet, forms hard clumps or
clods when it dries (Feels like modeling clay)
- The sediments provide structure for plants in the soil. They
give the roots something to hold onto.
- Air and water are also components of soil. These components
are necessary for plants to grow. The size of the sediments
affects how the soil holds air and water.
- Soil contains organic material. Living and once living (dead
and decaying) plant and animal matter. These organic materials
provide most of the nutrients plants need to grow.
- Plants can be grown without soil, if they are provided air, water,
and nutrients from another source.
Intended Learning Outcomes
1. Use Science Process and Thinking Skills
4. Communicate Effectively Using Science Language and Reasoning
Instructional Procedures
Invitation to Learn
Read the book Dirt by Steve "The Dirtmeister" Tomecek aloud to class.
Instructional Procedures
Make Soil Journals
Formation of Soil
- Give students a rock. Tell them their assignment is to turn
the rock into soil. Do not give them any more information.
Tell them they have 5 minutes to write their plan for turning
the rock into soil in their journals. They can use pictures,
words, phrases, or sentences.
- Show them a cake mix and explain that making soil is similar
to making a cake. Think about it...do you just put the box
into the oven and presto a cake comes out? What do you
need to do? (Add other things, mix them together, put it into
the oven and let it bake) Explain that making soil from rocks
is a process much like this. You have to add other things,
mix them together, and it takes time)
- The first step in turning rock into soil is that it must
be broken down into sediments--small pieces. (Pass out
containers of sediment for students to look at and touch)
Access students' prior knowledge about weathering and
ask them how rocks can be broken down. Make sure they
include wind, water, ice, plant roots, people. Once the rock
is broken down it is often moved to a different place. This
is called erosion. Access prior knowledge about erosion.
What forces cause erosion? (Wind, rivers, runoff, glaciers)
The sediments are piled up. Is it soil yet or just a pile of
sediment? It's not soil yet...it needs more.
- Think about the cake mix again. Pour the cake mix into a
bowl. The cake mix is like the pile of sediments. What do
we have to do to make this into a cake?
- Add eggs and oil
- The eggs and oil represent organic matter in the soil. Organic
matter is plants and animals, which die and start to decay in
the soil. Pass out containers of leaf mold. This is what leaves
look like after they have started to decay. Where do you
think the parts of the leaves that are gone went? (Into the
ground)
- So if organic matter gets mixed in with our pile of sediment
then they combine and we are getting closer to making soil, just
like we closer to turning this into a cake.
- Add water
- The cake mix needs water. Soil also needs water. Water
is a component of soil. Rain and snow seep into the pile of
sediments and organic matter.
- Mix up the cake mix
- Why do we mix up the ingredients? It combines them together
and it also adds another important component to the cake. It
adds air. That's why you have to mix a cake mix together for
several minutes...you need to add plenty of air into it or your
cake will look like a pancake!
- Soil is the same way. It needs air. That's why we dig or plow
or till soil before we plant.
- Air is added to the sediments and organic matter over time.
- The last thing we need to make the cake is time. You have to
put it in the oven and bake it. Soil also needs time. It's not
nearly as fast as a cake. A cake takes half an hour. Soil takes
hundreds of years.
- Serve a piece of cake to each of your students. Ask- "What
does your body do with the cake? It takes out the nutrients
your body needs--in cake there are lots of carbohydrates, which
provide energy for your body. Plants do the same thing. They
take the nutrients they need to live and grow out of the soil.
They are adapted to just take the nutrients out and leave the
other components of soil behind. (*Make sure your students
understand that plants don't "eat" soil the way we eat the cake).
Journals: Have the students make a graphic organizer to show a
timeline of the formation of rock. It should have at least 4 different
steps in the process of changing a rock into soil.
If students are struggling have class brainstorm some ideas together
to help them get started, or review the soil formation pages in the book
Dirt used for the Invitation to Learn. You could also make the graphic
organizer and run copies for the students if you feel they need it.
Assessment: Green Card/Red Card statements (you can add
additional statements)
- Soil is made from rocks.
- Changing rock to soil takes just a few weeks
Composition of Soil
- Average soil contains these amounts of the components
discussed in Step 1-Show the overhead transparency of the
circle graph
Inorganic (nonliving) 25% air 25% water Minerals 45% Organic
(living/once living) 5%
Give each student a copy of the circle graph. Paste them in
their journals and complete their own circle graph --fill in each
section to show that material (example: water blue drops;
air gray squiggles; mineral matter different colored pebbles;
organic matter-animals that live in the soil and decaying plants.
Extension: You could have students show the same percentages
on a bar graph to give them practice with different types of
graphs.
- Pass out containers of soil containing organic matter,
magnifying glasses, and paper towels.
- Tell students: We're going to examine this soil and see if we
can find the different components that make up soil. Which do
you think you will be able to see? Will there be any that you
can't see? You should be able to see the minerals; they are the
pieces of sediments. Rub the soil between your fingers and you
can feel the particles. Look for organic matter-living plants and
animals, and evidence of once-living things like bits of plants,
twigs, leaf, or parts of dead animals. You might be able to tell
that there is water by looking at the soil. Soil is darker when it
has moisture in it. You can feel the moisture by touching and
squeezing the soil, or you can look for dampness on the paper
towel-those are all proof of water in the soil. You will not be
able to see the air--but look for the spaces between the particles-
they are filled with air. Spread the soil out onto the paper
towel; examine it with the magnifying glasses. Separate the soil
into Non-living inorganic materials: minerals and evidence of
air and water and organic: living and once-living (decaying)
plant and animals.
Journals: Word Web graphic organizer- Teacher draws a model of
web on board or overhead for students to copy into their journals as
you discuss the components they discovered as they investigated the
soil sample.
Assessment: Red Card/Green Card Statements
- Soil is 45% organic material
- Soil contains both air and water
- Plants and worms are examples of inorganic, non-living material
in soil
- Soil is 45% mineral matter
Soil Particle Size and Texture
- There are hundreds of different types of soil in the world, but
all those types of soil are combinations of the three main types
of soil: sand, silt, and clay.
- These types of soils are identified by the size of the particles or
pieces of mineral matter in them.
- These jars (show the marbles, beans, rice) can help us compare
the particle size of the different types of soil.
- Sand: Sand has large particles like these marbles. Because these
particles are large they fit together loosely. You can feel the
particles in the sand, it feels like sugar. Open the container of
sugar and take a little bit of it. Rub it between your fingers.
What does it feel like? Now open your container of sand. Take
a little bit of it. Rub it between your fingers. Does it feel like
the sugar? That is because you can feel the individual particles.
What words would you use to describe how it feels? (Rough,
gritty, etc.) This tells us the TEXTURE of the soil. Take a few
drops of water and add it to the sand in your hand. What does
it feel like when it is wet?
- Repeat with the jar of beans, flour, and silt. Silt has smaller
particles, they are more finely textured. Silt feels smooth. It
often sticks to your hands. Silt is found near lakes and mouths
of rivers, or where soil particles have been carried by slow
moving water.
- Repeat with the jar of rice, modeling clay, and clay. Clay has
the smallest particles. They pack very closely together so there
is almost no space between them. Clay feels fine and slippery.
When it's wet it feel slick. When it dries it packs so closely
together that it is almost like cement. The dirt clods in your
garden that are really hard to break apart most likely have a lot
of clay in them.
- Optional: Make a sedimentator. You need a clear plastic jar
with a lid. Put in one cup of average soil and then fill with
water until jar is about 2/3 full. Shake jar vigorously for 1-2
minutes. Let it sit overnight. The sediments will settle out of
the water into layers of different soil types. The sand will settle
first and be the bottom layer because of its large particles. Silt particles will follow and form the second layer. Clay sediments
settle last, they might even take longer than 24 hours so keep
observing the jar for a few days. The organic matter will float
on top of the water.
Journals:
- Particle Size: Give students patterns of jars and have them trace
and cut out three jars and glue them into their journal. Label
each jar: sand, silt, and clay. Draw particles to show each type
of soil. Remind them that the bigger the particle, the bigger the
space between it. Have them look at the jars of marbles, beans,
and rice to see the difference in the size of the spaces.
- Texture: Have them write the name of each type of soil using
block letters that represent the texture of that soil. Example:
Sand--use pointy, rough looking letters, spread the letters far
apart. Fill in the letters with a texture pattern that represents
that soil. Choose one or two words that describe the texture of
that soil and write them underneath the name. Cut the name
and words out and glue into journal.
Assessment: Red Card/Green Card Assessment Statements
- Sand is rough and gritty and has large particles.
- Clay has the largest particles.
- Silt feels smooth like flour, it has medium sized particles.
- Sand particles pack very tightly together with no space between
them
- Clay feels slippery when its wet and dries rock hard
Air in Soil
Give each student a straw and give each group a container of water.
Tell them to blow bubbles in the water. Ask what made the bubbles?
(Air) Bubbles are evidence of air. Challenge class to think of other
examples of bubbles being evidence of air. (Fish tanks, scuba divers,
bubblegum bubbles, bottles of bubbles, etc.)
Give each group a measuring beaker, a cup of soil, and a cup of
water. Pour the water slowly over the soil. Watch very carefully for
bubbles. That is evidence of air in the soil. Where is the air in the soil?
(Fills the spaces between the particles)
Which types of soil, sand, silt, or clay do you think has the most
air? Which has the least air?
Why?
Journal: How can you show that there is air in the soil? Could you
add anything to the particle jars to show that there is air? Have them
color in the spaces between the particles gray and then make a key on
the page to show that gray = air.
On the next page have them do a drawing of each type of soil to
show how much air would be in it. Do a circle for each type of soil.
Have them fill the circle showing the particles and air in each type of
soil. Label each circle.
Assessment: Red Card/Green Card Assessment Statements:
- There is no air in soil.
- Air fills in the spaces between the particles in soil.
- The more tightly packed the particles the more air there will be
in soil.
- Sand has the largest particles so it has the largest spaces and the
most air.
- Clay has the smallest particles so it has the most air.
Water in Soil
- Get three different size (diameter) straws and tell the class that
you are going to have a race. Choose three students; give each
one a straw and a cup of water. Tell the class that the race is to
see who can suck all of the water out of their cup the fastest....
have them predict who they think will win and why. Conduct
the race.
Explain that water moves differently through different types
of soils. Water moves through the air spaces, so the more and
bigger the air spaces are, the more rapidly water can move
through it, just as the water moved more quickly through the
larger tube.
- Do "Pick a Path" activity to demonstrate: (from Dirt: Secrets
in Soil page 43 Utah Agriculture in the Classroom Utah State
University)
- Remind students what they learned about the particle and space
size in each soil type.
- Divide the students into four groups. Assign each group one of
the following titles: water, sand, silt, and clay.
- Give each member of the water group a raindrop cut from blue
paper.
- Have the sand group stand together so that just their fingertips
are touching. Their arms should be extended straight out.
- Have the silt group stand together with their elbows touching.
- Have the clay group stand together with their shoulders
touching.
- Tell the water group that their job is to make their way through
each soil group. Have them start with the sand. Discuss the
results. Repeat with the silt and clay. Have class come up with
a statement about how water moves through each type of soil.
- Do a demonstration with actual soil samples. Invite students up
close so they can observe closely. You need:
- A container of water and three paper cups
- 3 measuring beakers
- 3 funnels (you can use tops of 2 liter pop bottles) covered in
cheesecloth
- Sample of each soil type: sand, silt, and clay
- Place funnels on top of measuring beakers; place one soil
sample in each funnel. Do not pack them down. Slowly
pour a cup of water simultaneously into each of the soil-filled
funnels. Watch to see if water soaks into the soil quickly or if it
pools on top. Time for 1 minute and compare how much water
has passed through the soil into the beaker.
- Set timer for 4 more minutes. At the end of 4 minutes (total
time of 5 minutes) Compare again.
- Discuss results with class.
- Journals: Write a simile statement about how water moves
through each soil. Draw a drop of water for each soil and
illustrate to show how it moves through that soil.
- Example: Water moves through sand like a cheetah running.
- Then draw the water drop to look like a cheetah. (Other
possibilities: a jet plane, a racecar, a rocket ship, etc.)
- Silt: The raindrop could be a trotting horse, or a person jogging,
or a car driving through a neighborhood.
- Clay: The raindrop could be a tortoise or a snail.
- Ask students if they think that the water in soil will stay forever
or if it will leave. Leave the soil uncovered until the next day.
Have students check for moisture content again. Ask them
why they think the soil is drier and what caused it. Review
evaporation from the water cycle curriculum.
Assessment: Red Card/Green Card Assessment Statements:
- Water moves through all soils exactly the same.
- The bigger the particles the more quickly water will move
through soil.
- Water moves through the spaces between particles.
- Water moves quickly through clay soils.
- Water move quickly through sandy soils.
Organic Matter in Soil
Look back at the samples of soil that you separated into organic
and inorganic materials, and at the word web graphic organizer in your
journal. Review what types of things are organic matter.
Discuss: Why is organic material so important in soil? The organic
material is what provides the majority of the nutrients that plants need.
Dead and decaying plant and animal material provide fertilizer to the
soil. Without organic matter the soil would not be fertile and plants
would not grow well in it. This would be like you trying to live and
grow without food. Organic materials provide food for plants.
Journal: Life in Soil (2 pages- Blacklines in appendix)
Give each student a copy of the "Life in the Soil" outline and a copy
of the Is Organic /Is Not Organic worksheet. Cut out the Life in Soil
outline and glue it into their journals.
Have them look at each item on the Is Organic/Is Not Organic. If
they agree that is a correct example of organic matter in soil have them
cut it out and glue it onto the Life in Soil page.
Assessment: Red Card/Green Card Assessment Statements:
- Organic means the non-living matter in soil such as minerals,
air, and water
- You can find both living and once-living, organic matter in soil.
- Pieces of twigs and leaves are examples of once living material
in soil.
- Rocks are organic matter.
- Dead and decaying animals are once-living organic matter.
- Organic materials provide nutrients or food for plants to live
and grow.
How Do These Components of Soil Affect Plant?
- Show the class a plant in a pot. Make sure the plant has lots
of roots. Ask the class what soil has to do with plants. Review that soil is important because all life depends on the soil. Plants
need the soil to grow and animals eat the plants.
- Carefully take plant from pot and shake off some of the soil
so class can see the roots. The roots are the part of the plant
that grow down into the soil. What do the roots do and how
do they relate to the soil? Soil particles keep the roots in
place and help hold the plant up. The water, air, minerals, and
organic matter in the soil are all used by the plant to live and
grow. Plants take these things from the soil through their roots.
- Make sure you reinforce the concept that plants don't use up
the soil; they just use the components of the soil.
- What would happen to plants if there were too little or too
much of the different components of soil? Use creative
movement to show these situations. Act like a plant:
...in clay type soil that holds too much water so there is very
little air, and then dries rock hard. (Help, we're drowning,
there's no air, are roots are getting squished, they can't bring us
any food)
...in sandy soil that has large, loose particles where the water
flows through too quickly for the plants to use it. (Help we're
dying of thirst, we're falling over)
...in soil that has no organic material so it has no nutrients
(Help, we're starving to death, there's nothing to eat, we're small
and weak because we have no food.)
- Journal: Have students draw and label the soil and plants from
each situation they acted out in their journals.
Assessment: Red Card/Green Card Assessment Statements:
- Soil is necessary for all life on earth.
- If there was no soil on earth we would still be able to live
- Plants take air and water from the soil through their roots
- Plants grow best in soil that has no organic material in it
- Dead and decaying plants and animals add nutrients and food
for the plants to the soil
Extensions
- The What? No Soil? Mystery! We have learned that soil is
necessary for plants to live and grow. Do you think that plants
could ever grow without soil? What would you need to do?
You would need to find some other way to give them the things
like air, water, and nutrients that they usually get from the soil.
You would also have to find a way to support the plants without
having their roots held in soil. Scientists around the world are
studying ways to do this. Discuss why we would want to be
able to grow plants without soil.
- We're going to do an experiment and see if we could start
to grow plants without soil--maybe you can grow up to be
a scientist and work on this idea to help save our planet's
resources.
- Give each group 2 clear plastic cups. Have them moisten the
inside of one cup and sprinkle grass seed on the sides and
bottom of the cup. Then give them a paper towel and have
them moisten it. Carefully fit the paper towel inside the cup,
try to disturb the grass seed as little as possible. Place 2 or 3
beans on the paper towel. Take half of another paper towel,
moisten it and carefully place it on top of the beans. Put the
second cup upside down on top of the first cup and seal them
together with tape. Put the cups where they will get sunlight.
Observe them and watch for signs of plants growing. The grass
and beans should start to sprout within 2-3 days. Ask students
what they think will happen if they leave the grass just in the
cup. The grass will eventually die because it cannot get the
nutrients it needs. So plants can grow without soil but you
need to find a way to give them nutrients.
- Challenge your high level students to do some research on their
own, and share with the class ways scientists are working on
solving this problem. These methods are called hydroponics.
They could also research plants called epiphytes that grow on
other plants. The website kidsgardening.com has information
on this presented in a child friendly manner.
- Integration with language arts: Write similes for each type of
soil:
Sand is as rough as a scrub brush.
Silt is as smooth as silk.
Clay is as slippery as wet soap.
Or couplets:
Sand is gritty, loose, and dry
It hurts when it gets in your eye!
Silt is soft, powdery, and fine
If it's in your garden, you won't whine
Clay is slick when it's wet
But when it's dry, it's hard you bet
Family Connections
- Do a Soil Treasure Hunt activity. Ask students to bring in samples
from their yard or neighborhood that they think are sand, silt, or clay.
- Ask students to look for areas in their neighborhoods where plants
grow well and areas where they don't. Have them bring in soil samples
and compare them to see if they find out why.
Assessment Plan
- Red Card/Green Card: Stop Me If I'm Wrong statements after each
section.
- Teacher observation of activities, discussions, and journals
- Final Assessment: How Much Do You Really Know About Soil.
Bibliography
Research Basis
Krueger, A., &Sutton, J. (2001). EDThoughts What We Know About Science Teaching and Learning. (84)
Hands on experiences help students make meaning about
scientific phenomena and help students move from more concrete to
abstract levels of thinking. Ongoing learning assessment with timely,
focused feedback helps students attain deeper understanding.
Ruis-Primo, M.A., Li, M., Ayala, C., and Shavelson, R.J. (1999). Student Science Journals and
the Evidence they Provide: Classroom Learning and the Opportunity to Learn. (Paper
presented at the meeting of National Association for Research in Science Teaching.
Retrieved 1/4/2007 from http://www.education.ky.gov
A study of California fifth-graders, which looked at whether
journals were an effective way of assessing learning from inquiry, based
science lessons. Results showed a strong correlation between student
performances on journal entries with their achievement. Students
with low journal scores tended to have poor understanding of science
concepts. Journal writing can be a valid way to demonstrate science
achievement.