Developed by CLACE- PI Marina La Grave, Dr. Barry Kluger-Bell and Kristine Johnson
UNIT: Soil
LESSON # 5
TITLE: What Happens to Dead Plants in the Earth
Summary: This lesson deals with the question, What Materials:
happens to dead plants and animals in
for child observations
the earth? It is primarily a presentation
Quantity per
with artifacts for the children to examine. Item
group of 6–15
NASA Source: Adapted from information at NASA, Earth
Plants from
Observatory feature “The Carbon Cycle”
seeds
website
several for
planted in
http://earthobservatory.nasa.gov/Featur
demonstration
earlier
es/CarbonCycle/page1.php
lessons
Grade level: 3-5
Wooden
1 and 1 for
Time: Total time: 70 minutes
kitchen
Snack & introduction:
10 minutes
storyteller
match
Gather children:
5 minutes
Compost
Storytime:
45 minutes
from
1 or 2 sample
Journaling and cleanup:
10 minutes
previous
containers
Children Children will begin learning that:
lesson
Learning  Plants take carbon dioxide from the air Peat moss
several samples
and
make
plant
material
from
it.
Outcomes:
in plastic cups
 Humus is made via the decomposition
Coal
a few lumps
of organic material like plants. This
Oil (crude
decomposition returns carbon dioxide
oil if
a few vials
to the air.
available or
 Under certain conditions, over long
motor oil)
periods of time, plants can turn into
Fossilized
peat, coal, oil, natural gas or can
leaves or
fossilize and trap carbon in the earth.
fern
Children will engage in and thereby
(borrowed
1 or 2 samples
strengthen a number of scientific
from the
practices such as:
natural
 Observing the various forms of fossil
history
fuels.
museum)
 Communicating by listening to
information about fossil fuel formation
Word Wall:
and responding to questions.
Children will be able to (cultural goals):
Include following words in
 Relate overall science learning goals to
discussion (in both English and
the context of their schools, families,
Spanish), orally defined in
and community.
understandable terms, and
 Communicate ideas, collaborate with
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Developed by CLACE- PI Marina La Grave, Dr. Barry Kluger-Bell and Kristine Johnson
other children, and learn in a personally
meaningful way.
Big Questions:
Lesson format:
National
Standards
Addressed:
visibly displayed. If possible,
project a large image of the
words (and associated pictures)
on the wall of the teaching area.
 Carbon
• Carbono
 Carbon dioxide • Dióxido de
 What happens to organic material in the
carbono
earth?
 Fossil
• Fósiles
 How do fossil fuels and their use effect
 Fossil fuel
• Combustibles
carbon dioxide in the atmosphere?
fósiles
Presentation and hands-on observation.
 Humus
• Humus
This activity relates to the following
 Peat
• Turba
standards from the Next Generation
 Coal
• Carbón
Science Standards:
 Petroleum
• Petróleo
4-ESS3-1. Obtain and combine
(oil)
(aceite)
information to describe that energy
and fuels are derived from natural
resources and their uses affect the
environment.
5-PS1-3. Make observations and
measurements to identify materials
based on their properties.
5-LS1-1. Support an argument that plants
get the materials they need for growth
chiefly from air and water.
5-LS2-1. Develop a model to describe the
movement of matter among plants,
animals, decomposers, and the
environment.
DIRECTIONS:
Overview: This session involves two parts and one take-home activity:
1) Introduce the lesson.
2) Children listen to presentation and observe sample materials.
3) Instruction for Take-home Kit/activity.
Steps:
LESSON INTRODUCTION (10 minutes)
Tell children that today, we will find out about what happens to dead plants and
animals in the soil.
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Developed by CLACE- PI Marina La Grave, Dr. Barry Kluger-Bell and Kristine Johnson
LESSON LEARNING TASKS (60 minutes)
Tell Story (50 minutes)
Note to facilitator: the timings are approximate.
Introduction (2 mins)
Program leader says: “Today, we are going to talk about the soil, the air, plants and the
earth and something that is closely tied to all of them. That thing is carbon. Carbon is
found in many different substances, like carbon dioxide. You may have heard about the
greenhouse effect—how too much carbon dioxide in the atmosphere is acting like a
blanket holding the heat from the sun in and causing the Earth to get hotter and
changing our climate. The things that you have been learning about will help you
understand about this carbon dioxide in the atmosphere; what happens in a balanced
way and how humans have been causing more carbon dioxide in the atmosphere. We
will start this story by looking at plants.”
1. Plants (4 mins)
 At each table, have the children look at the plants growing from the seeds
planted in a previous lesson.
o The facilitator says, “Look at the plant parts – the leaves, the stems, and
think about the roots and the radishes or beans that will grow from these
plants.”
o Ask the children, “Where do you think this plant material comes from?
What do you think makes it up?” Have children talk at the table for 2 mins
and prepare to share 1 idea from each table.
 After the table groups have had time to think the facilitator takes a response
from each table group leader. Then program leader says,
o “It may be hard to believe, but most of the “stuff” that makes up the plant
material comes from the air. Plants take in carbon dioxide and, using the
energy from the sun, combine the carbon with water to make food for the
plant and building materials for the plant’s body. Leftover oxygen from
the water is released to the air. Growing plants of all sorts take carbon
dioxide out of the air and “trap” the carbon in the plant’s own body.
Think about a tree. It has a BIIIG body. That is a lot of carbon that used to
be in the air.”
o “The oxygen produced by plants is super important. Without plants there
would not be much available oxygen in the air. This oxygen is what we
and many other living things need to breathe; to live. We and all animals
and plants need this oxygen to live. Without plants to produce free
oxygen, there would not be any animals on Earth.”
o “When we (and all animals) breathe, we take in oxygen. Our body uses
oxygen to get energy from the food we eat and in the process, we breathe
out carbon dioxide. The carbon in the carbon dioxide we breathe out
comes from our food. The carbon in our food comes directly from plants
or from an animal that ate plants.”
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Developed by CLACE- PI Marina La Grave, Dr. Barry Kluger-Bell and Kristine Johnson
Show visuals of a man and a plant.
The facilitator now lights a wooden match. (And has each small group leader
light one.) (3 mins)
The facilitator says, “When we burn plants, or material from plants like
the wood in this match, the carbon in the plant material combines with
the oxygen in the air to produce heat and carbon dioxide. Burning plants
quickly returns the carbon dioxide to the air that the plant took out of the
air when it was growing and releases the energy that was stored. When
we eat plants, our bodies use the air we breathe in to do something
similar so we also return the carbon dioxide to the air and get the energy
that was stored for our bodies to use.”
2. Compost (4 mins)
 Bring out the compost produced in an earlier lesson and the facilitator says:
o “Eating or burning plants is not the only thing that can happen to plants.
Think about the composting that we did. What happened to the plants in
the compost pile often happens to dead plants in the soil. What can you
say about what happens to plants in the compost pile or similar things
that happens to dead plants in the soil?”
o Take some time to take comments from the children. What you are
looking for is something about decomposing and forming humus but do
not count on the children producing this idea.
o Build on the children’s responses to say, “Most plants, when they die and
enter the soil decompose. They are broken down into simpler parts and
used for food by microorganisms. This is what happened in our compost
containers.”
At each table look at the compost (3 mins). It would probably not be completely
decomposed at this point but have children notice the changes that have
happened on the way to complete decomposition. Take some comments from
the children on the changes that they notice and what they think will happen if
they gave it more time.
o The facilitator tells them that in the soil, the same kind of things happen
to the dead plants as what they saw in the compost containers. “In this
process, the microorganisms that are doing the decomposition, take
oxygen from the air, combine it with carbon from the plants, and return
carbon dioxide to the air. Not all of the carbon from the plants returns to
the air. Some of it can stay in the soil (in the humus). Humus helps plants
grow, and it is another place to “store” carbon that used to be in the air.”
3. Balance of carbon dioxide (1 min)
 “All of what we have been talking about so far is a nice, balanced carbon cycle
for the Earth. Plants take carbon dioxide from the atmosphere and, powered
by the sun, use the carbon to build plant material and release oxygen to the
atmosphere. When the plants are eaten, when they die and decompose, or
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Developed by CLACE- PI Marina La Grave, Dr. Barry Kluger-Bell and Kristine Johnson
are burned, the plant carbon is turned into carbon dioxide and returns it to
the atmosphere. Growing and decomposition can take time, as we saw with
our seeds and compost pile, but most of this happens over weeks or months
or, at most, years. If we look at longer periods of time, we can see other
things happening.”
4. Fossilized Leafs or Ferns (9 mins)
 The facilitator tells the children “When dead plants go into the soil,
decomposition is not the only thing that can happen. Take a look at what I am
about to lay on the table.”
 Lay the sample fossil leafs or ferns on the table and tell the children that they
can look but not to touch or to touch very gently under supervision. (6 mins)
Tell them how old the samples that you are showing them are and, if you
know, where they were found. Ask children what they notice. Tell them the
following:
o “When dead plants get buried in the soil in a way that oxygen from the air
cannot get to them, the decomposer microorganisms cannot do their
work. The plants are not broken down. Over millions of years, the weight
of all the material that falls on top of the soil where these plants are
buried compresses the plant and the carbon in the plant becomes part of
the rock. The carbon in the fossil is trapped and cannot return to the
atmosphere. But remember, this fossil formation takes place over
millions of years.
5. Look at the Peat Moss (4 mins)
 The facilitator tells the children, “Other things can happen to dead plants when they
get buried. Take a look at this. It is called peat or peat moss.”
Table leaders passes out the samples of peat moss to each group. (3 mins)
 The facilitator tells the children, “When plants like moss growing in wetlands die,
they can encounter cold, acidic conditions (think of cold vinegar!) where they do not
get any oxygen. The decomposer microorganisms are slowed down and/or stop
breaking down the plant material. The dead plants pack closely together and over
time, form something we call peat. Most peat bogs in the world, add only 1mm of
new peat per year (show with fingers). It can take hundreds or thousands of years
for peat to build up, as layers of new plant material grow on top of layers of
decomposing peat.
 Peat is another way that nature takes carbon dioxide out of the air. The peat stores
the carbon so that it does not make new carbon dioxide. When people burn peat as
fuel, they release carbon dioxide in minutes that took thousands of years to take out
of the air.”
6. Coal (5 mins)
At each table, have the children pass around the samples of coal. (4 mins)
 The facilitator tells children that what they are handling is called coal.
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Developed by CLACE- PI Marina La Grave, Dr. Barry Kluger-Bell and Kristine Johnson


“Sometime, over long periods of time, the Earth’s surface changes. Oceans and rivers
move sand, clay and other minerals that pile up and bury the peat. This accumulated
material can form sandstone or other rocks. The weight of these rocks squeeze the
water out of the peat and as the material got buried deeper, the temperature got
hotter. Over thousands to millions of years, this material turned into coal. Most of
the coal we use was formed about 300 million years ago, before the dinosaurs lived.
It took many millions of years to form the coal we now find.
Coal is mainly made of the carbon that the plants took from the carbon dioxide in
the air. Coal is a “rock” that burns. Humans burn coal to get the energy that was
originally stored in the coal that came from the plants that made the coal. Today, we
mainly use coal in power plants that make our electricity. But when we burn coal,
we put carbon (in the form of carbon dioxide) back into the atmosphere in a very
short time that took millions of years to accumulate in the coal. This added carbon
dioxide adds to global warming.”
7. Oil (Petroleum) (4 mins)
At each table, have the children pass around vials of oil. (3 mins)
 The facilitator tells the children that what they are handling is oil that comes from
petroleum.
 “All of our motor oil, gasoline, diesel fuel and fuel oil come from petroleum.
Petroleum is another substance formed from plants that get buried.
 Petroleum is created by the remains of small animal and plants dying, falling to the
bottom of the ocean or deep lake. Here they partially decompose leaving mainly the
carbon that the plants got from the carbon dioxide in the air. This decomposed
material is then compressed by billions of tons of silt and sand that cover them over
several million years. When the layer gets deep enough, the natural heat of the earth
and the intense pressure from all of the weight of the layer of silt and sand “cooks”
the material into liquid petroleum. Under some temperature conditions, this
material can also turn into natural gas.
 When we use gasoline or diesel oil to power our cars and trucks, or when we burn
fuel oil or natural gas to heat our homes we release some of the stored energy. But
we also put the carbon in the petroleum back into the atmosphere (in the form of
carbon dioxide) in a very short time that took millions of years to accumulate in the
petroleum. This added carbon dioxide adds to global warming.”
8. Discuss global warming (4 mins)
 “280–340 million years ago, before dinosaurs existed, the Earth was a very different
place. It was much warmer and more humid with lots of swampy areas. There was
much more carbon dioxide in the atmosphere. The carbon dioxide acted like a
blanket helping to keep the Earth warm.
 The warm swampy conditions were perfect for plant growth. The land was covered
with swamps filled with large trees, moss, ferns and other leafy plants. The water
and seas were filled with algae, which is actually millions of very small plants. Using
energy from sunlight, these plants built their bodies by taking carbon from the
carbon dioxide from the atmosphere.
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Developed by CLACE- PI Marina La Grave, Dr. Barry Kluger-Bell and Kristine Johnson





Many of these plants in the swamps were buried and, over millions of years, became
coal. Much of the algae fell to the bottom of the seas, were buried and over millions
of years became petroleum (oil) or natural gas.
The carbon that these plants took from the carbon dioxide in the atmosphere was
locked up in the coal and oil. The atmosphere contained much less carbon dioxide.
And, like when we have a thinner blanket, things got cooler.”
“Today, we call coal and oil fossil fuels because they were made so long ago. We
burn them to produce energy—to create electrical power, to run our cars and other
vehicles and to heat our houses. But this burning puts carbon dioxide back into the
atmosphere. And, like getting a thicker blanket, the Earth heats up.
When the plants that formed the coal and oil removed carbon dioxide from the
atmosphere and lowered the Earth’s temperature, it happened over millions of
years. Living things had time to evolve, to change and adjust to the lower
temperatures. But by burning fossil fuels in large quantities, we are putting that
carbon dioxide back into the atmosphere and raising the temperature over
hundreds of years instead of millions. Many living things may not have enough time
to evolve to deal with the changing conditions.”
“What can we do to help reduce the amount of carbon being put back into the
atmosphere? The answer is helping to store carbon or using less energy from fossil
fuels.” Give one example of each and take ideas from the children on how they can
do something to store carbon or use less energy.
o Storing:
 Plant trees.
 Recycle paper (keep trees from being cut down).
 Compost.
 Conserver natural vegetation.
o Using less energy:
 Switch lights in your house to energy saving bulbs.
 Reduce, reuse, recycle (takes less energy than making new things).
 Keep your house temperature cooler and wear warmer clothes.
 Turn lights, computers and all your chargers off and unplug them
when they are not in use.
 Only do full loads of laundry.
 Take shorter showers.
 Use your bike or walk instead of riding in a car.
Journaling and cleanup (10 minutes)
Tell the children to draw a picture of one thing they could do to reduce their energy use.
From this lesson, children should have learned:
 Plants take carbon dioxide from the air and make plant material from it.
 Humus is made via the decomposition of organic material like plants. This
decomposition returns carbon dioxide to the air.
 Under certain conditions, over long periods of time, plants can turn into peat, coal,
oil, natural gas or can fossilize and trap carbon in the earth.
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Developed by CLACE- PI Marina La Grave, Dr. Barry Kluger-Bell and Kristine Johnson
ASSESSMENT:
 Ongoing, through the discussion and activities: monitor children’s usage and
understanding of words and ideas related to today’s lesson. Ask supporting questions
to encourage children to make connections. Clarify misconceptions.
 Demonstrations of understanding: do any drawings, writing, theater, etc., display
sophisticated, accurate understanding of today’s lesson? Were children able to make
personal connections to the ideas? Were children able to make connections to prior
lessons?
 Take-Home work (assessed following week): did children follow through and discuss
the lesson with their families, bring a related show and tell object, and/or make a
drawing/other art project related to today’s lesson? Did discussion around these things
show continuing understanding of the ideas, including making connections to prior
lessons and to community?
 Do children’s understandings, as displayed by their demonstrations of understanding,
questions, and discussion show connections between today’s topic, and the big picture
of the unit topic?
 Photograph objects and save drawings brought in for sharing in individual child’s
portfolio. Do the artifacts in the portfolio demonstrate an increasing trajectory of
understanding about the elements of the Earth System over time? Do children show
understanding of climate change? Do children show personal connections, including
self, school, family, and community, to their understandings of climate change?
RELATED NASA ACTIVITIES AND RESOURCES:
Soil Science Education
http://soils.gsfc.nasa.gov/
The portal to a large array of NASA education resources on soil.
Earth Observatory: The Carbon Cycle
http://earthobservatory.nasa.gov/Features/CarbonCycle/page1.php
Introduction to basics about the Carbon Cycle.
Earth Observatory: The Slow Carbon Cycle
http://earthobservatory.nasa.gov/Features/CarbonCycle/page2.php
The movement of carbon between the atmosphere and the Lithosphere (rocks), including
formation and burning of fossil fuels.
Earth Observatory: The Fast Carbon Cycle
http://earthobservatory.nasa.gov/Features/CarbonCycle/page3.php
The movement of carbon through life forms on Earth, or the biosphere.
Earth Observatory: Changes in the Carbon Cycle
http://earthobservatory.nasa.gov/Features/CarbonCycle/page4.php
Includes human caused changes due to use of fossil fuels.
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Developed by CLACE- PI Marina La Grave, Dr. Barry Kluger-Bell and Kristine Johnson
Earth Observatory: The Effects of Changing the Carbon Cycle
http://earthobservatory.nasa.gov/Features/CarbonCycle/page5.php
Includes climate change and global warming.
BACKGROUND INFORMATION:
Background information for this lesson is contained in the lesson itself.
CULTURAL BACKGROUND INFORMATION:
Communities around the world have adapted their agricultural needs to its soils and
geography.
During pre-Hispanic times one of the methods of agriculture of ancient peoples of
Mesoamerica was by the system of "chinampas.” The Toltecs developed this system. A
“chinampa” is something like a floating garden that was planted on the banks of lakes. The
soil of a chinampa was obtained from the bottom of the lake, and thanks to its nourishing
properties, crops prospered and were able to produce up to 6 harvests per year. An
important fact of this practice is that a sustainable chinampas did not need watering, as
plants simply absorbed the water off the lake or from rain. “Ahuejotes”, (willow tress) were
planted on the banks of the chinampas in order to provide greater stability.
Many countries continue to use this sustainable ancient practice!
LESSON CONNECTIONS
The soil unit has two strands. The soil strand deals with what makes up soil and what soil
contributes to life. The transformation strand deals with change over time including how
soil is made and things growing in soil.
This lesson is tied to ideas in other lessons:
In Lesson 1 (What makes up soil), children learn about the components of soil (sand, silt,
clay and humus). They begin to make humus by constructing a composter.
In Lesson 2 (What makes soil), children learn some basic soil profiles and how rocks and
minerals are broken down into soil by weathering and other processes.
In Lesson 3 (What makes soil good for growing), children explore what makes soil that is
good to grow things in and how plant roots interact with the soil.
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Developed by CLACE- PI Marina La Grave, Dr. Barry Kluger-Bell and Kristine Johnson
In Lesson 4 (What lives in the soil), children learn about things that live in the soil from
microscopic bacteria to worms and bugs to burrowing mammals like rabbits.
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