Hello, this is Mr. James.

I hope you're feeling ready to learn some science.

Are you feeling curious? Good.

Let's begin.

Starting with our lesson outcome.

And today our lesson outcome is this.

I can plan a fair test investigation to compare how water moves through different soils.

As always, there are going to be some keywords that will help you with your learning.

So let's take a look.

Our first keyword is this one.

Do you know it? It's permeable.

Permeable.

Can you say that after me? Permeable.

Plan.

Fair test.

Variables.

Well done.

Let's have a think about what these words actually mean.

If a material or a substance is permeable, it allows liquids and gases to pass through it.

A plan is a method that maps out the steps that you'll take during an investigation.

A fair test is where only one variable is changed to see what effect that has on the results of the investigation.

So what's a variable? You need to know what that is.

Well, variables are things which can be changed and measured in an investigation.

Here's the outline for today's lesson.

We're going to think about the questions that scientists ask about soil first, and then we're going to go on to planning a permeability test.

So let's start with scientists asking questions about soil.

There are so many fabulous science jobs out there.

What sort of scientist thinks about the soil in their job? Well, soil scientists study the first few metres of the earth's crust.

Here we can see a soil scientist checking out a sample.

So where do they work? Where do soil scientists work? They work outside.

They dig for soil samples, and also they work in laboratories where they observe and investigate the soil samples that they've collected when they were outside.

Different types of soil provide varying conditions.

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

So for example, we might think about the best type of soil to farm crops on, or the best type of soil for sheep farming.

So to sum up the job of the soil scientists, it's this.

Helping farmers to improve the quality of their soils, to grow healthy crops and produce grass to feed animals.

Soil scientists help engineers that are solving problems such as flooded land, erosion, or landslides.

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

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

So what might a soil scientist ask questions about? What do you think? Is it A, space? B, the oceans? C, the Earth's crust? Or D, animals? Yeah, it's C, the Earth's crust.

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

Here's an aerial photograph.

What sort of landscape do you think this is showing? They compare different types of land, soil, vegetation, and climate to discover their effect on the landscape.

And they can see from images like this one which soils are more permeable.

Being a soil scientist is an interesting and varied job.

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

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

Plants that need moist soil grow in these wetlands.

For which of these purposes would a soil scientist's questions about soil be useful? Time to have a think.

Is it Sofia? She says, to help a farmer to improve his land to grow more crops.

Jacob says, to help an engineer decide the best place to build houses.

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.

Well, a soil scientist's questions about the soil would be useful to help a farmer to improve his land to grow more crops.

And it would also be helpful to an engineer to decide the best place to build houses.

It wouldn't really help a manufacturer decide the best material for making a car.

But yes, it would help conservationists create a conservation project in wetland areas.

Soil scientists ask different questions about soil and the land before carrying out investigations to solve problems. Alex thinks about this.

I wonder what sort of questions they ask? A soil scientist might ask, what's the best soil to use to improve a farmer's field to grow different crops? Or perhaps, which soil would be the best to build a new park on? Or, 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.

So let's think about this.

Which of these questions might a soil scientists ask? What do you think? Is it A, which soil is cheapest from my local garden centre? B, which soil is best for growing crops? Or C, which soil will reduce flooding? Just take a moment to think of your answer.

Yeah, it's the second two, not the first one.

Which soil is best for growing crops, and which soil will reduce flooding.

The scientists ask questions about soil, and here we can see an extremely muddy football pitch.

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

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

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 their permeability, can you think of an inquiry question for the soil scientist to investigate? Discuss your ideas with a partner.

Pause the video now while you do that.

That's great work.

Well done.

I wonder what questions you came up with.

Well, you might have thought of an inquiry question for the soil scientist to investigate a bit like this.

What would be the best soil to use to create a dryer football pitch? Or which soil would drain the quickest? Or which soil is the most permeable, or which soil is the least permeable? Which soil does not hold water? Great job if you came up with a question that was something like that.

Now we move on to the second part of our lesson, planning 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? Just think about that for a moment.

Pause the video if you need to.

I wonder what you thought.

Permeable soil lets water pass through it easily and quickly.

And 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.

Permeable soils often feel dry quickly after it's rained.

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

So what happens to permeable soil when water's poured on it? Time for you to have a little think about that.

Here are some options.

A, it doesn't let the water flow through it easily.

B, water flows through it slowly.

C, it allows water to flow through it easily.

Or D, it doesn't hold the water for a long time.

What do you think? Pause the video if you need to.

Yes, it was the last two of those options.

Permeable soil, if you pour water on it, it allows the water to flow through it easily and it doesn't hold the water for a long time.

So getting back to the football pitch problem, which type of soil do you think will be most suitable for that new football pitch? Who do you agree with? Well, Lucas says, I think the soil scientist needs to find the least permeable soil.

And Sam, she says, I think they would need to find the most permeable soil.

Pause the video for a moment and have a think about this.

Cool.

Well done.

Well, I think, Sam said, they'd need to find the most permeable soil.

And she's quite right.

The most permeable soil will allow the most amount of water to pass through.

Here's our scientist, our soil scientist, with an inquiry question, and it's this.

Which type of soil is the most permeable? Well, she says, I'll need to plan a fair test to help me answer this question.

In a fair test, only one thing has changed, and that's the thing you are asking the question about.

So in this fair test, the only thing that our soil scientist is going to change is the type of soil.

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

I'll need to keep everything else the same.

So here we can see the three soil samples that our scientist has collected.

The things that we can change or keep the same in a fair test investigation are called variables.

Lucas and Sam are making sure they understand this fair test investigation.

Lucas says, so, in a fair test, only one variable is changed, and all the other variables must stay the same.

Well, Sam says, yes, everything else must stay the same, such as the amount of soil being tested, the amount of water poured onto the soil.

Can you think of any other variables that must be kept the same? Have a think now.

Pause the video.

I hope you found a few.

There always are quite a few when you think about it.

So who do you agree with? Lucas: To keep a test fair, you need to keep all the variables the same.

Sam: To keep a test fair, you need to keep one variable the same.

or Jun: To keep a test fair, you only change the variable you want to test.

The other variables stay the same.

Pause the video if you need to.

Yeah, Jun, to keep a a test fair, you only change the variable you want to test.

The other variables, well, they all stay the same.

Back to our soil scientist.

In my plan, I'll also need to decide what I will do to test soil permeability and what equipment I will need, such as these things.

A funnel, filter paper, a measuring jug, plastic bottle, and a timer.

Have a good look at this equipment and take a moment to think about how you could use it to plan a fair test.

Pause the video to talk about that now.

I don't know about you, but I always find it quite exciting planning for an investigation.

So which piece of equipment would a scientist use to measure how permeable a soil is? Would it be A, a magnet, B, a timer, or C, a force metre? What do you think? Take a moment to think about it and pause the video if you need to.

Yes, out of those three options, a timer would be the most useful piece of equipment for measuring the permeability of soil.

So we need to, for our task B, plan our permeability test.

So create a plan to help you find out which type of soil is most permeable.

Decide what equipment you'll need, including two to three soil samples from different locations.

Explain in numbered steps, writing, or diagrams, what you will do.

And as this is a fair test, you'll need to include which variable you'll change and which variables you will keep the same.

Pause the video now and start to think about planning your permeability test.

Here's a little more detail on what your test might look like.

Your test plan, that is.

Well, deciding what equipment you'll need.

We talked about a funnel, filter paper, plastic bottle, measuring jug, timer, water and soil.

Those soil samples, remember? Explain in numbered steps, writing or diagrams what you will do.

Here's an example.

Number one, place a funnel inside a plastic bottle.

Number two, put filter paper inside the funnel.

Number three, add a cup full of soil onto the filter paper.

Four, place the end of the funnel into an empty recycled plastic bottle.

Five, slowly pour an agreed amount of water onto the soil.

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

Seven, repeat steps two to six with the other soil samples.

Number three of our permeability test plan.

As it's a fair test, you do need to include which variables you will change and which ones you are going to keep the same.

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.

The variables that I'll keep the same will be the amount of soil, the amount of water, and the temperature of the water.

Scientists ask questions about which type of soil is best 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're going to need.

In a fair test, only the variable you are testing should be changed.

All the other variables, well, they must be kept the same.

That's a lot of thinking you've been doing today about soil scientists and soil permeability.

Well done and see you next time.

Bye.