Dig deep
View Sequence overviewStudents will:
- investigate and model soil layers.
Students will represent their understanding as they:
- design and create a labelled model of soil layers.
- undertake a gallery walk.
In this lesson, assessment is summative.
Students working at the achievement standard should have:
- demonstrated an understanding that rocks, and therefore minerals are components of soil, and that soil, rocks and minerals have observable properties that affect their use.
- constructed a physical model that shows simple relationships.
- applied their learning when creating their labelled model of soil layers.
Evidence should be found in student models and during the gallery walk.
Refer to the Australian Curriculum content links on the Our design decisions tab for further information.
Whole class
The video Organic Matter on the Soil (0:58)
The video Soil Health, Humus (0:27)
The video The 5 Layers of Soil (3:39)
Optional: Shovel and access to a location on the schoolgrounds where you can dig a hole and observe soil layers. Alternatively, a pre-dug sod of soil with grasses, weeds intact.
Demonstration copy of the Soil layers and labels Resource sheet (digital or hard-copy)
Food safe preparation area if the models are edible
Each group
Glass or clear plastic jar
Materials for soil layers, for example:
- natural materials such as stones, sand and leaves.
- edible items such as cookies, choc chips, marshmallows and sour worms.
- other suitable items such as coloured paper, paper clips, cotton wool, string/wool, etc.
Soil layers and labels Resource sheet
Scissors
Glue, sticky tape or blutac
Each student
Individual science journal (digital or hard-copy)
Lesson
The Inquire phase allows students to cycle progressively and with increasing complexity through the key science ideas related to the core concepts. Each Inquire cycle is divided into three teaching and learning routines that allow students to systematically build their knowledge and skills in science and incorporate this into their current understanding of the world.
When designing a teaching sequence, it is important to consider the knowledge and skills that students will need in the final Act phase. Consider what the students already know and identify the steps that need to be taken to reach the level required. How could you facilitate students’ understanding at each step? What investigations could be designed to build the skills at each step?
Read more about using the LIA FrameworkRe-orient
Review the previous lessons, focusing on what is in soil and in particular:
- the analysis of a cup of soil in Lesson 2—stones/rocks, leaves, insects, sand.
- the soil profiles made in Lesson 3—the layers of different matter that settled in the jars.
- rock—soils contain pieces of rock and rocks are made of minerals.
The Inquire phase allows students to cycle progressively and with increasing complexity through the key science ideas related to the core concepts. Each Inquire cycle is divided into three teaching and learning routines that allow students to systematically build their knowledge and skills in science and incorporate this into their current understanding of the world.
When designing a teaching sequence, it is important to consider the knowledge and skills that students will need in the final Act phase. Consider what the students already know and identify the steps that need to be taken to reach the level required. How could you facilitate students’ understanding at each step? What investigations could be designed to build the skills at each step?
Read more about using the LIA FrameworkIdentifying and constructing questions is the creative driver of the inquiry process. It allows students to explore what they know and how they know it. During the Inquire phase of the LIA Framework, the Question routine allows for past activities to be reviewed and to set the scene for the investigation that students will undertake. The use of effective questioning techniques can influence students’ view and interpretation of upcoming content, open them to exploration and link to their current interests and science capital.
When designing a teaching sequence, it is important to spend some time considering the mindset of students at the start of each Inquire phase. What do you want students to be thinking about, what do they already know and what is the best way for them to approach the task? What might tap into their curiosity?
Read more about using the LIA FrameworkWhat’s underneath the soil?
Revisit the terms:
- organic matter—living or dead plants and animals and their wastes. Show the video Organic Matter on the Soil (0:58).
- humus—dark crumbly material of decomposed organic matter. Show the video Soil Health, Humus (0:27).
- What organic matter have we found in our soil samples and school yard?
- Leaves, worms, bugs, ants, fungus, dead leaves.
- Why is it important to have organic matter in soil?
- Organic matter breaks down and provides nutrients for plants—similar to how people need food, worms make holes for roots to grow into.
- Can we see a dark humus layer in our school garden?
- Can we create extra humus to add to the top of our soil?
- Yes, through composting.
Pose the question: If we keep digging through the soil, what would we find underneath it?
The Inquire phase allows students to cycle progressively and with increasing complexity through the key science ideas related to the core concepts. Each Inquire cycle is divided into three teaching and learning routines that allow students to systematically build their knowledge and skills in science and incorporate this into their current understanding of the world.
When designing a teaching sequence, it is important to consider the knowledge and skills that students will need in the final Act phase. Consider what the students already know and identify the steps that need to be taken to reach the level required. How could you facilitate students’ understanding at each step? What investigations could be designed to build the skills at each step?
Read more about using the LIA FrameworkThe Investigate routine provides students with an opportunity to explore the key ideas of science, to plan and conduct an investigation, and to gather and record data. The investigations are designed to systematically develop content knowledge and skills through increasingly complex processes of structured inquiry, guided inquiry and open inquiry approaches. Students are encouraged to process data to identify trends and patterns and link them to the real-world context of the teaching sequence.
When designing a teaching sequence, consider the diagnostic assessment (Launch phase) that identified the alternative conceptions that students held. Are there activities that challenge these ideas and provide openings for discussion? What content knowledge and skills do students need to be able to complete the final (Act phase) task? How could you systematically build these through the investigation routines? Are there opportunities to build students’ understanding and skills in the science inquiry processes through the successive investigations?
Read more about using the LIA FrameworkBuilding soil layers
Show the video The 5 Layers of Soil (3:39). Explain that the broken rock layer is called ‘weathered rock’ or ‘parent material’ (as in the video). We will use the term ‘weathered rock’ as it is more descriptive.
Using the demonstration copy of the Soil layers and labels Resource sheet, create a labelled diagram of soil layers.
Optional: Investigate what soil layers are visible in the local area by digging a hole with the class or examining a pre-dug sod of soil. Discuss and compare the local soil to the soil in the video.
- What soil layers can we see?
- Is there an obvious layer of organic matter and humus on top?
- What do we predict we would see if we could dig down further?
- Are the layers easy to see?
Students then construct a model of soil layers in teams. They should label the layers using the Soil layers and labels Resource sheet. Discuss the materials they will be using and any required safety precautions.
Allow time for teams to plan and construct their model of soil layers.
Soil layers
How deep does soil go, and what’s underneath it?
Soil is not a single uniform layer but a complex structure made up of several distinct layers.
The uppermost layer, called organic material, consists of living or dead plants and animals and their waste. Over time the organic material breaks down to form humus, a dark crumbly material rich in vital nutrients.
Beneath it lies the topsoil, which is often dark in colour due to humus and organic material. It is rich in minerals essential for plant growth. Most plant roots, earthworms, insects and micro-organisms can be found here.
Below that is the subsoil, containing less organic matter but more minerals and clay, often making it lighter in colour.
Deeper still is weathered rock. Over time bedrock has broken down into smaller pieces, forming this weathered rock layer. Soil from above has also made its way down and is mixed with the rock pieces.
At the very bottom is the bedrock, the solid foundation from which all other soil layers are formed. Bedrock covers the earth and is found under all continents and the sea floor. Note that bedrock is made of different types of rock in different places such as granite, sandstone, limestone. The term ‘bedrock’ means the solid rock below us once you dig down through the soil and weathered rock near the surface. This is important as ‘bedrock’ features in Minecraft and many students who play Minecraft believe that it is a type of rock.
Each layer plays a crucial role in the soil’s ability to support life. In some locations the soil layers may be easily distinguished when digging deep with machinery. In others, the layers will be less obvious, and some layers may not be present at all. For example, Uluru is an outcrop of sandstone bedrock and is not covered by layers of soil.
Soil is not a single uniform layer but a complex structure made up of several distinct layers.
The uppermost layer, called organic material, consists of living or dead plants and animals and their waste. Over time the organic material breaks down to form humus, a dark crumbly material rich in vital nutrients.
Beneath it lies the topsoil, which is often dark in colour due to humus and organic material. It is rich in minerals essential for plant growth. Most plant roots, earthworms, insects and micro-organisms can be found here.
Below that is the subsoil, containing less organic matter but more minerals and clay, often making it lighter in colour.
Deeper still is weathered rock. Over time bedrock has broken down into smaller pieces, forming this weathered rock layer. Soil from above has also made its way down and is mixed with the rock pieces.
At the very bottom is the bedrock, the solid foundation from which all other soil layers are formed. Bedrock covers the earth and is found under all continents and the sea floor. Note that bedrock is made of different types of rock in different places such as granite, sandstone, limestone. The term ‘bedrock’ means the solid rock below us once you dig down through the soil and weathered rock near the surface. This is important as ‘bedrock’ features in Minecraft and many students who play Minecraft believe that it is a type of rock.
Each layer plays a crucial role in the soil’s ability to support life. In some locations the soil layers may be easily distinguished when digging deep with machinery. In others, the layers will be less obvious, and some layers may not be present at all. For example, Uluru is an outcrop of sandstone bedrock and is not covered by layers of soil.
The Inquire phase allows students to cycle progressively and with increasing complexity through the key science ideas related to the core concepts. Each Inquire cycle is divided into three teaching and learning routines that allow students to systematically build their knowledge and skills in science and incorporate this into their current understanding of the world.
When designing a teaching sequence, it is important to consider the knowledge and skills that students will need in the final Act phase. Consider what the students already know and identify the steps that need to be taken to reach the level required. How could you facilitate students’ understanding at each step? What investigations could be designed to build the skills at each step?
Read more about using the LIA FrameworkFollowing an investigation, the Integrate routine provides time and space for data to be evaluated and insights to be synthesized. It reveals new insights, consolidates and refines representations, generalises context and broadens students’ perspectives. It allows student thinking to become visible and opens formative feedback opportunities. It may also lead to further questions being asked, allowing the Inquire phase to start again.
When designing a teaching sequence, consider the diagnostic assessment that was undertaken during the Launch phase. Consider if alternative conceptions could be used as a jumping off point to discussions. How could students represent their learning in a way that would support formative feedback opportunities? Could small summative assessment occur at different stages in the teaching sequence?
Read more about using the LIA FrameworkModelling soil layers
Conduct a gallery walk for students to see how others have approached the task, provide opportunities for feedback and to make any alterations to their work. Use the huddle method to focus on teams’ work during the gallery walk, drawing attention to specific things as described in the discussion prompts below.
- What is the deepest/thickest layer in this model? Does that match what we have learned about soil layers?
- How has this team represented the bedrock/organic matter?
- What else could they have used?
- If you were pushing a stick or pole into the ground, which layer do you think you would push down to? Why do you think that? Would be influenced by how heavy the stick or pole was, or if it was holding something up?
Reflect on the lesson
You might:
- review the TWLH chart. Record what students have learned about soil layers and add any new questions.
- add to the class word wall vocabulary related to soil layers.
- discuss how students were thinking and working like scientists during the lesson. Focus on creating a model to communicate science knowledge and understanding.
Huddle method
What is the huddle method?
The huddle method is a simple strategy to get students to focus on a particular work sample that demonstrates features or ideas that will support the development of student understanding. They often occur during a gallery walk, when you want students to focus on a specific work sample.
- Call a 'huddle' and direct students to stand in a location where they can see the work clearly.
- Use questioning and discussion to guide a conversation about the features you would like to draw attention to. For example, one team may have represented many forms of organic matter in their organic material and topsoil layers, such as worms, roots, and decaying plant matter.
- Consider carefully the questions you will pose to the class and to the team/student whose work you are examining. For example, you might first ask the class what organic matter they think has been represented, then ask the team to confirm or add to this. You might continue to question and discuss the role of each thing in term of making 'healthy' soil.
- Students might progress to calling their own 'huddles' around work samples they'd like to discuss.
Take care to consider and manage negative or discouraging questioning and discussion during a huddle.
Many teachers use this, or similar, strategies under different names, such as 'fishbowl', 'assemble', 'cluster' etc.
The huddle method is a simple strategy to get students to focus on a particular work sample that demonstrates features or ideas that will support the development of student understanding. They often occur during a gallery walk, when you want students to focus on a specific work sample.
- Call a 'huddle' and direct students to stand in a location where they can see the work clearly.
- Use questioning and discussion to guide a conversation about the features you would like to draw attention to. For example, one team may have represented many forms of organic matter in their organic material and topsoil layers, such as worms, roots, and decaying plant matter.
- Consider carefully the questions you will pose to the class and to the team/student whose work you are examining. For example, you might first ask the class what organic matter they think has been represented, then ask the team to confirm or add to this. You might continue to question and discuss the role of each thing in term of making 'healthy' soil.
- Students might progress to calling their own 'huddles' around work samples they'd like to discuss.
Take care to consider and manage negative or discouraging questioning and discussion during a huddle.
Many teachers use this, or similar, strategies under different names, such as 'fishbowl', 'assemble', 'cluster' etc.