This episode of SciShow Kids is made in partnership with our friends at Soil Cycle
[♪ intro ♪ ]
Hey, everyone!
Squeaks and I just got back from our nature walk, and it’s time to record our observations.
[Squeaks squeaks in excitement.]
Okay, what did we see today?
[Squeaks]
Some oak trees;
I bet those grew from the acorns we see by the woods!
[squeak]
We saw blackbirds.
Remember when they had just hatched earlier this year?
[squeak]
Oh yeah, all of the seeds we planted this spring have grown into beautiful flowers!
We have such good soil in our garden —
or what you sometimes hear called dirt.
The good soil really made a great place for those little seeds to grow.
What else, Squeaks?
Oh, what are you thinking about?
[Squeak squeaks.]
Oh, that’s such a good question.
Squeaks was just asking where soil comes from.
On our walk, we saw plants that came from seeds and birds that came from eggs,
so what about soil?
Well, soil comes from a few places!
And it’s made all the time outside,
just by everyday things happening in nature!
Soil is mostly made of tiny bits of rock.
Over hundreds or even thousands of years,
big rocks are slowly broken into smaller pieces.
And there are a few ways that can happen.
For example, this can happen as waves from a stream or an ocean hit rocks,
or as strong winds blow on them.
When that happens, the wind or water slowly breaks off tiny pieces of rock
and sweeps them away.
Or, sometimes, rocks are trapped under lots of other, heavy rocks.
And if the rocks on top shift or scrape against the rocks on the bottom
, that can break the rocks [on the bottom] into smaller pieces, too.
Rain can even get into holes in rocks, and freeze there in the winter.
And then, the ice can slowly crack rocks wide open.
No matter how it happens, when rocks are broken into pieces like this,
we call it weathering.
And even plants and animals can weather rocks!
Roots can split rocks as plants grow,
and digging animals like moles can scratch up rocks as they burrow around them.
Now, Squeaks, you know there are lots of different kinds of rocks, right?
They come in all different colors and textures.
Do you think that they all make the same kind of soil?
[Squeaks squeaks.]
You’re right, different rocks make all different kinds of soil.
Rocks like quartz are really hard,
so they take a long time to weather, and when they do,
they make hard, grainy soils like sand.
Other rocks, like shale, are a little easier to break.
So shale, for example, weathers into really teeny-tiny pieces, and makes thick, softer
soils like clay.
Soil isn’t just rock, though.
It also contains living things,
and pieces of things that used to be alive.
Things like dead leaves, bits of old logs and plant stems,
even old bones and fur that have broken down over many months or years
— they’re all part of soil.
Scientists call these pieces of plants, animals, and fungi organic matter.
And it’s full of nutrients, the stuff that plants need to survive.
Some soil is full of organic matter, so it’s really good for growing plants.
Other soil doesn’t have as much.
[Squeaks squeaks] Good question!
How can you tell which soils have a lot of organic matter?
Well, organic matter is dark black.
So you can guess how much organic matter is in soil by looking at how dark a color it
is.
The closer it is to black, the more organic matter is in it.
[Squeaks squeaks] Good eye!
The soil in our garden is really dark.
Good, black soil has a bunch of organic matter in it, so it’s great for growing flowers.
Soil is made out in nature every day, but it does take a very long time.
The soil you see outside was made over many years —
around a hundred years for just the top layer of soil!
And every day, rocks and organic matter are changing just a little bit,
slowly turning into more and more soil.
[Squeaks makes a suggestion.]
Ooh!
Maybe we can see how things change as we take more nature walks, Squeaks.
That sounds fun.
We’ll have to take some good notes if we’re going to notice where soil is being made outside,
though.
And You can become a neighborhood soil scientist, too!
See where soil is being created near your home or school,
and look closely at what the color of the soil around you might tell you.
Are there tree roots weathering rocks, or are there dead leaves or other organic matter
mixed in with the soil?
You can record your findings like Squeaks and I do,
and we’ll be excited to have another soil scientist to share in our observations.
And speaking of soil.
the next few SciShow Kids episodes are brought to you by our friends at Soil Cycle
They collect food scraps and make compost in the town of Missoula, Montana
They do really cool things with soil and we were excitex to partner with them to make
these episodes
If you wanna learn more about soil you can hit the subscribe button
We’ll be talking about soil a lot this month at the fort
See you next time
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