Work through this resource material in the following sequence:

10-15 minutes

Tune In: What lives in the soil?

25 minutes

Find Out: Soil food chains

20 minutes

Take Action: A soil food chain short story

5 minutes

Reflection

Tune In: What lives in the soil?

Step 1

Begin this lesson by setting the scene for students:

Ask students to put on their soil scientist lab coats. Today we will be taking a deeper dive into what’s under our feet and how what’s underground impacts us.

Step 2

Share the following image with students (also available here):

Invite students to share what they see in this image.

Differentiation: You could invite a student requiring extension to annotate the drawing or record ideas about what students see in this image on the board.

Step 3

Now share the following image (also available here):

Take a moment to talk through this image with students and compare it to what you saw in the un-annotated version of the image:

did they see all these things in the image the first time around?
how many different types of organisms can they see in this image?
how many organisms can they count overall? Note: You could remind students of this image and how many organisms are in one gram of soil!
what do students already know about how all these organisms are connected? For example, some organisms might be the main food source for other organisms.
what do students already know about how these organisms are connected to their environment? For example, some organisms might break down dead plant materials and turn them into food for other creatures, while other creatures just eat stuff.

Explain to students that it is okay if they don’t know the answer to the final two questions because, in this lesson, they will be working as soil scientists to investigate what these relationships might be. The important thing here is to introduce that these organisms do have relationships and that many are connected to each other and to their environment.

Find Out: Soil food chains

Step 1

Write the following term up on the board:

food chain

Invite students to speculate what they think this might be.

You can then share this video:

Once complete, invite students to share what they observed in this video and what they found interesting or surprising.

Below are some points from this video that you might like to include in your discussion:

Food chain - A food chain is a model (or visual representation) that shows how energy flows between living things. As discussed earlier in this clip, all living things need to eat! The food that we eat is called energy because it gives us the power to grow and live (this is a different type of energy from the one that is used to make electricity). A food chain shows us what eats what in an ecosystem.
Plants and energy - When plants take the energy from the sun's rays and change it into chemical energy, this is called photosynthesis (and this is why plants need sunlight to grow and be healthy).
Habitat - A habitat is the natural home or environment of an animal, plant, or other organisms.
Ecosystem - An ecosystem is an area where plants, animals, and other organisms, as well as weather and landscape, work together to form a community of life. An ecosystem includes all the living and non-living things and how they interact.

Step 2

Once complete, pose the following question:

what would the model showing the energy flow between the sun, grass, rabbit and hawk look like?

Invite students to have a go at creating a food chain on the board involving these four parts.

You can then clarify student understanding by creating a correct food chain or sharing the image below (also available here):

Through this process, explain to students that in a food chain, the arrows flow in the direction of the energy. So, in this case, the energy moves from the sun to the plant. Then when the rabbit eats the plant, the energy moves from the plant to the rabbit. And then, when the hawk eats the rabbit, the energy moves from the rabbit to the hawk.

Step 3

Invite students to have a go at creating another food chain based on the scenario below (differentiation: students could work as a class, in groups or individually, depending on their level of understanding and confidence):

Scenario - A flower is growing in a hot sunny desert. A butterfly collects nectar from the flower and then flies away to find another flower. On the way, it is plucked out of the air by a bird and eaten! The bird feels full after its snack, so rests on the ground. But along comes a hungry dingo; it catches and eats the bird.

Pose the question:

can you show the energy flow in this story as a food chain?

Step 4

Invite students to take a look at the food chains they created and pose the following questions:

what happens to the bird after the dingo has eaten it?
what do you think happens when the animals in the food chain poop (create waste)? Is there energy in this waste? What might happen to this energy?
what do you think happens when the animals at the top of the food chain (i.e. the hawk or the dingo) die? Where does the energy go? Does it just disappear?

Introduce students to the idea that there are some organisms whose role in a food chain is to break down dead organic matter and waste and convert this energy from these materials into nutrients that are cycled into the soil and then absorbed by plants. These organisms are known as ‘decomposers’.

Step 5

Explain to students:

What types of organisms are decomposers? Many organisms that live in the soil have some role in breaking down dead materials and helping the nutrients from these materials move through the soil. Some examples of decomposers in the soil include fungi, earthworms, nematodes and bacteria. You might remember some of these organisms featured in the images at the start of this lesson!

Extend: If time permits, you could explain to students that food chains are a useful tool in helping us to understand some of the ways that energy moves through an ecosystem. The problem is they don’t show us all the ways that energy can move in one ecosystem because many plants are eaten by many different animals, and those animals are also eaten by different animals, which might eat both plants and animals, which means that the flow of energy is never just a straight line. This is why scientists have created food chains - these are more complex and show how energy travels in an ecosystem (for example, see this soil food web).

Take Action: A soil food chain short story

Step 1

Students will now put on their soil scientists hats and create a short story that describes the relationship and flow of energy between 3 animals in a soil food chain. The aim of this story is to show people who aren’t very familiar with life in the soil that there is a whole world of stories and characters happening right under our feet!

Students will use the information about soil organisms on this Soil Organisms in Food Chai ns sheet to help them plan and write their stories.

Differentiation: Students can work independently or in pairs to complete this task. The length of the story can be adjusted according to the extension or support required for students.

In creating their stories, students should spend time planning them, particularly focusing on storylines, characters and settings before working on their final drafts. For example:

will their characters have names? How will you decide on the names? Will you use the features or characteristics of these organisms to inspire your names (e.g. Wriggly the Earthworm, Mini the Mite, or Stringy the Fungi).
where will you set your story? It may be easiest to set it in the soil, but you may want to be more specific and set it in the tunnel of an earthworm, the nest of an ant or around the roots of a plant.
what will happen in your story? Remember that you have to show how the energy is transferred between the organisms, so there is plenty of scope for drama with organisms being chased and eaten! You will also need to consider how your story will start and end.

You could also cut out and distribute the organisms on this sheet to understand more about the size, features and movements of these organisms. Students could conduct further research on these organisms.

Students can use this rubric to help them plan and write their stories.

Extend: If time permits, invite students to illustrate their stories.

Step 2

Students/pairs should share their work with another student/pair to help them review and edit their work.

Reflection

Invite students to discuss the following:

what did you find interesting or surprising about this lesson?
what questions do you still have about what you looked at in this lesson?
what do you think life in the soil tells us about how healthy the soil is?
why are soil scientists important to us? What are they finding out that could help us?

Differentiated learning

We trust that teachers are the best equipped to know how to cater to the diversity in their classes. At Cool, we incorporate a variety of differentiation strategies into each lesson. Firstly, each lesson in this unit appeals to an array of different learning preferences. Learning activities can be completed in a number of different ways - if a student feels more comfortable speaking rather than writing, there are opportunities to accommodate this.

In lessons that feature group work or learning stations, we trust that teachers will use their discretion in knowing how to best organise their students in accordance with positive working relationships and ability. Graphic organisers and scaffolds are often included so students can ‘visually think’ and keep a record of their work. While our lessons are designed to be 55 - 60 minutes in length, we trust that teachers will manipulate lesson and segment times according to the needs of their students.

Soil Food Chains

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