Hello everyone and welcome to our science lesson today.

Today we are going to be planning an investigation to find out about the permeability of soils.

Now, don't worry if you're not sure about what that word means.

We are going to be finding out all about that very, very soon.

And this lesson comes from the unit Rocks and soils.

The outcome for today's lesson is: I can plan an investigation to compare how water moves through different soils.

So that might already give you a clue about what permeability means.

Have a think about it.

What do you think it means? Permeable is our first keyword that we're going to be using in the lesson today.

We're also going to be using these keywords: plan, comparative test, and variables.

And here are some keyword definitions.

Now, you might want to pause the video and take some time to read through these definitions, or you might want to wait until further on in the lesson, maybe even at the very end, and come back and check your understanding of these keywords.

In the first part of the lesson today, we are going to be learning about how scientists ask questions about soil.

Is everyone ready to get started? Yes? Off we go.

Soil scientists study the first few metres of Earth's crust.

Where does a soil scientist work? Have a think about it, and you might want to share your ideas with somebody else.

Well done.

Soil scientists work outside, often digging for soil samples and also inside in laboratories where they observe and investigate the soil samples they have collected.

Now, did you know that there are different types of soil? And different types of soil provide varying conditions.

Soil scientists ask questions about which type of soil is best for different purposes.

So they might consider which is the best type of soil for growing crops, or which is the best or the most suitable type of soil for sheep farming.

Different types of soil for different purposes.

Soil scientists help farmers to improve the quality of their soils to grow healthy crops, and also to produce grass to feed animals such as sheep.

Soil scientists also help people like engineers when they're solving problems such as considering land that has been flooded or erosion of land or landslides.

And we have a photograph here of land that has been flooded.

They ask questions about different types of soils and investigate how to make them more permeable to reduce flooding.

Now, here's our keyword, permeable.

And today, do you remember, we are planning an investigation to find out more about soil permeability.

So if we're looking at making soils more permeable to reduce flooding, does that give you any clues about what that word means? I think it could be.

What do you think? Something to do with how easily liquids such as water are able to pass through the soils.

Okay, let's move on and find out more.

Permeable soils allow water to flow through easily, which means the land dries out quickly.

And that's really important, isn't it? If you live in an area where there's likely to be floods, you really want the water to flow through the soil quickly so that it can dry out.

Let's take a moment to carry out a quick check for understanding.

What might a soil scientist ask questions about? Is it A, space; B, oceans; C, Earth's crust; D, animals? Take a moment to gather your thoughts and choose your answer that you think is correct.

And the answer is C, Earth's crust.

Well done.

And the crust of the Earth is the outside layer of our planet.

Soil scientists use aerial photographs and satellite images to research different areas of the country.

And we have a fabulous aerial photograph here that was taken high up above looking down onto Earth's surface.

Soil scientists compare different types of land, soil, vegetation, and climate to discover their effect on the landscape.

And they can see from the images which soils are more permeable.

Being a soil scientist is an interesting and varied job, and that means that I would imagine no two days are the same.

Lots of different interesting things to do and investigate.

Soil scientists may be involved in conservation to help provide a suitable environment for birds, other animals, and plants to thrive.

Take a look at this photograph of wetland.

You can see there are animals and plants that depend on this habitat to grow and stay healthy and survive.

The soil in the wetland needs to have low permeability so it stays wet for the animals suited to this habitat.

And don't forget the plants as well that need moist soil to grow in these wetlands.

So this is the opposite, isn't it, to soil that you might find in an area that's prone to flooding, where that kind of soil would need to have a high permeability to allow the water to flow through.

Whereas in wetlands, we want the soil to stay wet, so we would need soil with a low permeability.

Let's take time for a quick check for understanding.

For which of these purposes would a soil scientist's questions about soil be useful? And we've got four children with four different suggestions.

And Sofia says, "To help a farmer to improve his land to grow more crops." And Jacob says, "To help an engineer decide the best place to build houses." And Laura says, "To help a manufacturer decide the best material to make a car." And Andeep says, "To help conservationists create a conservation project in wetland areas." Now that would be to help to protect the plants and animals that live there.

So pause the video and think about which of these would a soil scientist's questions about soil be useful? Have you had time to make your decisions? Now I have a feeling that more than one of these suggestions are correct.

So let's make a start.

Sofia is correct saying that, yes, a soil scientist could definitely help a farmer to improve his land, and also Jacob to help an engineer decide the best place to build houses.

Now, unfortunately, Laura, I don't think a soil scientist's question would help a manufacturer decide the best material for making a car.

And how about Andeep's? Did you agree? Yes, to help conservationists.

Definitely.

Well done, everyone.

So we've been thinking about how soil scientist's questions can help people.

Soil scientists ask different types of questions about soil and the land before carrying out investigations to solve problems. Now, Alex is saying, "I wonder what sort of questions they ask?" Do you know? Pause the video and have a think about what different types of questions soil scientists might ask.

A soil scientist might ask, what is the best soil to use to improve a farmer's field to grow different crops? A soil scientist might ask, which soil would be the best to build a new park on? Or maybe they might ask, what can I do to improve the soil conditions in these wetlands? The soil scientist then needs to create a plan to work out the best way to carry out their investigation.

And here's another keyword in the lesson today, plan.

And I'm sure that you've had opportunities to plan science investigations before, have you? Well, we'll be finding out more about how to make a plan coming up later on in this lesson.

Before we do, let's take time to check your understanding.

Which of these questions might a soil scientist ask? Is it A, which soil is cheapest from my local garden centre? Is it B, which soil is best for growing crops? Or is it C, which soil will reduce flooding? And the answers here are B and C.

Well done, everyone.

A soil scientist has been asked to help a football team improve their football pitch as it gets too muddy when rainwater doesn't drain away quickly enough.

Goodness me, take a look at the photograph of that muddy football pitch.

They definitely need a more permeable soil, don't they, to help the rainwater to drain through more easily.

The soil scientist will first need to create a question about the soil to investigate.

And this is known as an inquiry question.

To help the football team, think about the problem and what you know about types of soil and permeability.

Think of an inquiry question for the soil scientist to investigate.

And it would be a great idea if you could discuss your ideas with a partner.

So I want you to imagine that you are the soil scientist and we are going to start our investigation with your inquiry question, and it needs to be something to do with the type of soil and the permeability of the soil.

So pause the video and take some time to formulate your inquiry question.

Well done, soil scientists.

You might have created some questions like this.

What would be the best soil to use to create a drier football pitch? Was your question similar to that? Or maybe, which soil would drain the quickest? Or which soil is the most permeable or the least permeable? Or which soil does not hold water? Now remember, your question may have been different to these, so take a little bit more time and share your ideas with the people around you.

We are moving on to the second part of this lesson now, and we are looking at how to plan a permeability test.

A soil scientist needs to know which soils are permeable.

This helps them to understand which types of soil are best for different purposes.

Do you know what happens to permeable soil when it rains? Take a look at this photograph of a rainy day, and we see that a large puddle has formed on the ground.

Now we know that some of this rainwater will pass through into the soil below.

Do you know what happens to permeable soil when it rains? Permeable soil lets water pass through it easily and quickly.

We know that some soils are less permeable than others.

A soil with low permeability holds the water and only allows it to move through the soil slowly.

So we have a photograph here of some quite dry soil, and that's because permeable soils often feel dry quickly after it's rained.

And we know now, don't we, that that's because they've allowed the water to flow through.

We have a photograph here of some wet soil.

Less permeable soils often feel wet and sticky for a long time after it has rained.

Now, they do let the water slowly flow through them, but just much more slowly because this is a less permeable soil.

Let's check our understanding.

What happens to permeable soil when water is poured onto it? Now really think about what we know and what we've learned so far about permeable soil.

Is it A, it doesn't let the water flow through it easily? Or B, water flows through it slowly? Or C, it allows water to flow through it easily? Or D, it doesn't hold the water for a long time? So take some time to go through each of these options and choose which you think is correct.

And the answers are C and D, because we know that if a soil is permeable and water is poured onto it, it allows the water to flow through it easily because it's permeable soil.

And that also means that it doesn't hold the water for a long time.

Did you get those correct? Very good work, scientists.

Another check now.

Which type of soil will be most suitable for the new football pitch, and who do you agree with? Now, Lucas is saying, "I think the soil scientist needs to find the least permeable soil." And Sam is saying, "I think they would need to find the most permeable soil." So we're thinking again, aren't we, about our understanding of what that keyword permeable means.

Take a moment.

Who do you agree with, Lucas or Sam? Yes, Sam is correct.

The soil scientist needs to find the most permeable soil because it will allow the most amount of water to pass through.

We have our soil scientist here saying, "My inquiry question is, which type of soil is the most permeable?" Can you remember your questions that you created as part of the first practise task? Did anybody come up with the same question as this? Now, the soil scientist is also saying, "I will need to plan a comparative test to help me answer this question." Now we know that we need to plan the investigation, and we need to just double check that we know what our keyword comparative test means.

And the scientist is saying, in a comparative test, only one thing has changed.

This is the thing you are asking the question about.

So let's go back to the question, which type of soil is the most permeable? So the thing that we're asking the question about is the type of soil.

So in this case, that's the only thing that we're going to change when we carry out our comparative test.

So we could investigate different types of soil, couldn't we? And maybe we could pour water through them and maybe we could find out which soil is the most permeable, the one that lets the water flow through it most quickly and most easily.

Now, that sounds like a really good investigation to plan, doesn't it? Now, remember, in this comparative test, the only thing I will change is the type of soil.

So we keep going back to our inquiry question, and that gives us that big clue, doesn't it, the type of soil.

It's right there in our question.

Now this is exactly what the soil scientist is planning to do.

"In my comparative test, I will change the type of soil, so I have found different samples of soil from different places to test and compare.

I will need to keep everything else the same." That's fantastic.

So we've got three different samples of soil from three different locations, and these are the three samples that we're going to test.

Now remember, scientists, the things that we can change, measure, or keep the same in an investigation are called variables.

Fantastic.

So actually the type of soil is a variable that we are going to change.

Now, Lucas is saying, "So in a comparative test, only one variable is changed, and all other variables must stay the same." And Sam is agreeing with Lucas, saying, "Yes, everything else must stay the same, such as the amount of soil being tested." That's true.

So we're changing the type of soil, but we still need to use the same amount of soil each time.

What else will need to stay the same, Sam? Now Sam is suggesting the amount of water that we pour onto the soil.

Now that makes good sense, doesn't it? So we need to measure out an agreed amount of water and make sure that that's the same amount that's poured on each different type of soil.

It's very, very important to remember that we're only changing one variable, the type of soil, but all the other variables must be kept the same.

And Sam's given us two starters, two really great ideas.

Can you think of any other variables that must be kept the same in our comparative test? Pause the video and take some time to have a think.

Did you come up with any ideas? I was thinking about maybe the temperature of the water needs to stay the same.

So it would be no good pouring hot water or warm water or cold water onto the different soils each time.

Did you come up with anything else? Let's take time for a quick check for understanding.

Who do you agree with? Lucas is saying, "To compare in a fair way, you need to keep all the variables the same." And Sam is saying, "To compare in a fair way, you need to keep one variable the same." And Jun is saying, "To compare in a fair way, you only change the variable you want to test.

The other variables stay the same." Who do you agree with? It gets a bit confusing, doesn't it? But we are going to agree with Jun.

Well done, Jun.

Don't forget that you only change the variable that you are going to test.

So we're only changing one variable, and all the other variables need to stay the same.

So we're moving on with our plan, and we have our soil scientist saying that, "In my plan, I also need to decide what I will do to test soil permeability and what equipment I will need, such as these things." So we've got lots of equipment gathered together here for our soil permeability investigation.

We have a funnel and some folded filter paper.

We have a measuring jug, a plastic bottle, and a timer.

And again, pause the video and think about how could you use this equipment to compare soils.

Well done.

Now I want you to keep those ideas in your head because we are going to be using these ideas in our second practise task, which is coming up very soon.

But first, let's do one final check for understanding.

And we're thinking about scientific equipment.

Which piece of equipment would a scientist use to measure how permeable a soil is? Is it A, a magnet; B, a timer; or C, a force metre? And the answer is B.

Well done if you got that one right.

I think that a scientist would use a timer to time how long it takes an amount of liquid to flow through a certain type of soil, and then they could do it again and again with different types of soil, and they could use those measurements of time to compare.

So moving on to our final practise task now.

And do you remember I asked you to keep those ideas safe? And I want you to use those ideas to create a plan to help you to find out which type of soil is the most permeable.

So first of all, you're going to decide what equipment you'll need.

And don't forget that needs to include two to three soil samples from different locations.

After that, I would like you to explain, in numbered steps, so you could write sentences or draw diagrams or both if you would prefer, but you need to explain what you will do.

So how you will use that equipment and how you plan to investigate.

And then finally, don't forget, as this is a comparative test, you need to include which variable you will change and which variables you will keep the same.

So there's quite a lot to include in this plan.

Now don't forget, this part of the lesson is not to actually carry out your comparative test.

It is just to really think about and create the plan for what you will do another time.

Pause the video and start planning.

Now, you might have planned to use some of this equipment: a funnel, filter paper, plastic bottle, measuring jug, timer, water, and soil.

But remember, you might have some different ideas.

Moving on.

Let's think about either writing or drawing diagrams or both to explain what you will do.

So if you decided to write the instructions of your plan, it might look something similar to this.

Put filter paper inside the funnel.

Add a cup of soil into the filter paper.

Place the end of the funnel into an empty recycled plastic bottle.

Slowly pour an agreed amount of water onto the soil.

Time for five minutes, and then measure how much water has passed through the soil into the plastic bottle using the measuring jug.

Repeat steps with the other soil samples.

Now remember, your plan might be completely different to this.

You might have entirely different ideas, but this is one way of doing it.

You also might have drawn some diagrams to help you to plan out and remember exactly what you're going to do.

Now, the final part of this task is to think about which variable you will change and which variables you will keep the same in your comparative test.

The variable I will change is the type of soil.

Changing this will allow me to see what effect that has on the results of the investigation.

And the variables I will keep the same are the amount of soil, the amount of water, and the temperature of the water.

Did you come up with any other variables that you will keep the same? You may have done.

Take some time to share your ideas.

Fantastic work, scientists.

I'm really proud of all the learning that's taken place today.

Let's take a final moment to have a look at a summary of our learning.

Scientists ask questions about which type of soil is best for different purposes.

So remember that not all soil is exactly the same and there are different types, and they're best or they're most suited for different purposes.

Water moves very easily through permeable soils, and very slowly through soils with low permeability.

Scientists make plans that include what they will do and what equipment they will need, just like you've done in this lesson today.

And finally, we've learned a lot about a comparative test, haven't we? Remember, only the variable you are testing should be changed, and all other variables must be kept the same.

Well done, everyone.

I'm really looking forward to us carrying out this comparative test together.

So I will see you again, ready to investigate.