土壤是如何形成的？

ABC，听好了。

ABC listen.

你好。

Hello.

我在这儿。

Nij here.

今天在《想象一下》节目中，正是苹果收获季。

And today on Imagine This, it's apple season.

果园里有很多苹果树，地上也落了不少苹果。

There's lots of apple trees, and there's lots of apples on the ground.

是的。

Yeah.

我在农场帮忙采摘。

I'm on a farm doing some picking.

能来帮个忙吗？

Wanna give me a hand?

是的

Yeah.

这个不错。

Here's a good one.

我可以吃这个吗？

Can I eat this?

当然可以。

For sure.

随便吃。

Help yourself.

真好吃。

Yummy.

这里还长什么？

What else grows here?

水果。

Fruits.

草莓。

Strawberry.

是的。

Yeah.

这里有

There's

草莓、大黄、大蒜和洋葱。

strawberries, rhubarb, garlic, and onions.

真的很了不起。

Pretty amazing.

所有这些都长在我们脚下的土地里。

It all comes from the ground under our feet.

来自土壤。

From Soil.

而这正是今天要讨论的问题。

And that's what today's question is all about.

你好，尼吉。

Hi, Nij.

我是埃薇，今年七岁。

I'm Evie, and I am seven years old.

我想知道土壤是怎么形成的？

And I want to know how is soil made?

这是个好问题。

That's a good question.

土壤啊

Soil

其实到处都有。

is kind of everywhere.

但它到底是从哪儿来的呢？

But where does it come from?

也许土壤是来自植物，因为它们需要土壤才能生长。

Maybe soil comes from plants and some because it maybe helps them grow.

是的

Yeah.

土壤来自昆虫。

Soil comes from from insects.

也许吧。

Maybe.

来自地底下。

Comes from the ground.

也许是堆肥？

Maybe compost?

我觉得我得吃点东西才能想明白这个。

I think I need some brain food for this.

选择边缘很重要。

It's important to choose edge.

天哪。

Oh, no.

这儿没垃圾桶。

There's no bin.

直接扔地上就行。

Just chuck it on the ground.

这不算乱扔垃圾吗？

Isn't that littering?

不算。

Nah.

它会像堆肥一样变成土壤。

It'll turn into soil like compost.

只能是水果这类东西，塑料不行。

Only stuff like fruit, not plastic.

你确定吗？

Are you sure?

我觉得土壤不是由苹果核组成的。

I don't think soil is made of apple cores.

是吗？

Is it?

也许吧。

Maybe.

我不确定。

I don't know.

我们该去问问土壤专家。

We should ask a soil scientist.

有人提到土壤专家了吗？

Did someone say soil scientist?

萨姆·格罗弗教授。

Professor Sam Grover.

你好。

Hello.

刚才听到你们在讨论土壤问题，忍不住插一句。

Couldn't help but overhear your wonderful soil questions.

萨姆在RMIT领导着土壤-大气-人类圈实验室。

Sam leads the Soil Atmosphere Anthroposphere Lab at RMIT.

人类圈。

Anthroposphere.

萨姆。

Sam

她和团队对土壤、环境与人类之间的关联了如指掌。

and her team know all about the connections between soil, the environment, and people.

没错。

That's right.

如果你们需要，我可以帮你们解答这些关于土壤的问题。

I can help you with those soil questions if you'd like.

好的，麻烦你了。

Yes, please.

不过回实验室一趟得花不少时间。

It'll take too long to get back to the lab, though.

那我们不如来想象一下？

So how about a bit of imagining instead?

对。

Yeah.

我们可以跟着尼吉的苹果核，看看它在土壤里的旅程。

We can follow Nij's apple core on its journey through the soil.

啊，所以我可以直接把它扔在地上？

Ah, so I can put it on the ground.

这不算乱扔垃圾吧？

It's not littering?

我可不会随便乱丢，比如扔在路上或人行道上，但要是埋在这棵树下的土里，那就完全没问题。

Well, I wouldn't chuck it anywhere, like on the road or a footpath, but in some soil under this tree is just fine.

把它放进去，然后我们想象自己变得跟一颗苹果籽那么小。

Pop it there, and let's imagine we're as small as an apple seed.

我们往下走吧。

Down we go.

一切都好大好大啊。

Everything is so ginormous and big.

哇哦。

Woah.

这个苹果核大得像栋房子。

The apple core is as big as a house.

我觉得我肯定吃不完这个。

And I don't think that I will be able to eat one.

Nij，别吃那个。

Nij, don't eat that.

哎呀，真恶心。

Oh, gross.

别闹了。

Come on.

现在我们变小了。

Now we're tiny.

还有很多东西可以吃呢。

There's way more to eat.

但它在地下啊。

But it's on the ground.

来吧。

Come on.

五秒规则，没事的。

Five second rule.

吃起来还是挺香的。

It still tastes good.

你不是

You're not

唯一这么想的人。

the only one to think so.

你听到了吗？

Can you hear that?

它可能正朝那棵树过来。

It could be coming towards the tree.

听起来像有很多脚步声。

It sounds like it sounds like lots of feet.

是只

It's a

大部队在奔逃。

stampede.

近了。

Close.

是千足虫。

It's a millipede.

天哪。

Woah.

它大得跟过山车一样。

It's as big as a roller coaster.

这是一辆过山车，不过是一条过山狗。

It's a roller coaster, but it's a roller dog.

它要带我们兜一圈了。

And it's gonna take us for a ride.

快点。

Quick.

跳上去。

Jump

到处都颠得厉害。

on.

它背上的凸起就像过山车的座位一样。

It's really bumpy everywhere.

哇哦。

Wow.

它背上的凸起就像过山车的座位一样。

The bumps in its back are like seats on the roller coaster.

上面可能连安全带都没有。

No seatbelts on it, maybe.

像马陆、蚯蚓、甲虫和潮虫这类小生物，被称为分解者。

Little critters like millipedes, worms, beetles, and slaters are called detritivores or decomposers.

它们是表层土壤里的清洁团队。

They're the cleanup crew at this top layer of soil.

我猜它们可不是拿拖把和吸尘器来打扫的。

Something tells me they don't clean up with mops and vacuum cleaners.

会不会是它们身体里的某种东西，能帮土壤变得更肥沃？

Maybe something in their body just, like, helps the soil to grow like, to come into soil?

没错。

Yes.

分解者的作用就是把东西分解掉。

Decomposers help decompose things.

它们吃植物的残渣，比如这个苹果核。

They eat old bits of plants, like this apple core.

它们也会吃其他死去的动物，甚至粪便。

They'll eat other animals that have died, even poo.

听起来真恶心。

That sounds disgusting.

它们会吃牛粪吗？

Do they eat cow poo?

提醒我以后别跟马陆一起吃饭。

Remind me not to have dinner with a slater anytime soon.

对我们来说很脏，但对土壤健康至关重要。

Yucky to us, but vital for healthy soil.

抓紧了。

Hang on tight.

我们要下去了。

We're going under.

哇哦。

Yeehaw.

我们在哪儿？

Where are we?

看起来全是隧道。

Looks like lots of tunnels.

天哪。

Woah.

小心点。

Look out.

你右边有条蚯蚓。

Earthworm on your right.

对。

Yes.

这些由蚯蚓和其他昆虫挖出的隧道对土壤健康至关重要，它们能让空气、水分和植物根系自由通过。

These tunnels made by worms and other insects are an important part of healthy soil because they let air, water and the roots of plants move through it.

太神奇了。

Wow.

下面居然有这么多生命。

There is so much life down here.

你根本想象不到。

You have no idea.

一茶匙土壤里的生物数量，可能比地球上的人口还多。

There can be more life in just a single teaspoon of soil than there are human beings on earth.

这真是太棒了。

That's really cool.

我能看到蚯蚓、蚂蚁、马陆、甲虫。

I can see a worm, ants, millipedes, beetles.

我觉得我好像还看到一个……那是蠼螋吗？

I think I can see a is that a earwig?

这味道可真够重的。

That's a lot of funk.

不过我可看不到几十亿个生物。

I can't see billions, though.

其他人去哪儿了？

Where's everyone else?

你马上就知道了。

You're about to find out.

那是什么？

What's that?

幼虫。

Larvae.

虫子的宝宝。

Bug babies.

它们在吃什么呢？

Are they eating hey.

那是我的苹果核吗？

Is that my apple core?

现在还说不上是你的苹果核，但它们可能在清理几周前从树上掉下来的那个。

It's too soon to be your apple, but they might be finishing off one that dropped off the tree a few weeks ago.

也许它们吃了东西之后，把排泄物当成土壤排出来？

Maybe they eat food and then prune it out as soil?

对。

Yes.

这些幼虫在制造一种叫粪沙的东西。

These larvae are making something called frass.

粪沙？

Frass?

其实就是粪便。

It's basically poop.

因为我觉得这对植物生长有帮助。

Because I think it helps the plants grow.

没错。

That's right.

它看起来像深色的粉末，说明树木和其他植物也能从这种苹果残渣里吸收养分。

It looks like a dark powder, and it means that the trees and other plants can also get the nutrients from things like this apple.

所以土壤是用苹果核做的？

So soil is made from apple cores?

可以这么说。

It can be.

对。

Yes.

土壤主要是细小的岩石颗粒，混着空气、水分，再加一点有机物。

Soil is lots of tiny bits of rock mixed with air and water and a dash of organic matter.

有机物？

Organic matter?

就是以前活过的东西，比如枯叶、从树上掉下来的水果，甚至死去的动物和昆虫。

So that's things that used to be alive, like old leaves, a fruit that's fallen off trees, even animals and bugs that have died.

所以土壤就是石头、水，还有死掉的东西？

So soil is rock and water is dead stuff?

其实里面也有很多活的东西，比如这些小家伙。

It's made of lots of alive stuff too, like these guys.

这些虫子也算土壤的一部分吗？

The bugs count as part of the soil?

当然算。

For sure.

土壤是一个生态系统。

Soil's an ecosystem.

它是这些活的和死的东西共同组成的群体。

It's a community of all these alive and unalive things working together.

它们就像一群饿坏了的小宝宝。

They're hungry babies.

确实如此。

Sure are.

它们吃得多，拉得也多。

They eat a lot and, well, they poo a lot too.

接下来我们就说说这个。

And that's where we're headed next.

天哪，不会吧。

Oh, no.

没错。

Oh, yes.

现在来想象一下自己成为

Time to imagine being

哇，小虫虫的屁股。

Woah, baby bug's bum.

你还记得之前问过其他人去哪儿了吗？

Remember when you asked where everyone else was?

瞧，他们都在这儿呢。

Well, here they are.

我能看见细菌。

I can see bacteria.

好多啊。

So many.

是的。

Yes.

在显微镜下，土壤里充满了细菌、真菌、古菌和病毒。

At the microscopic level, soil is full of bacteria, fungi, archaea, and viruses.

我现在能看到几十亿个了。

I can see billions now.

这简直是个微生物大都会。

It's a microbial metropolis.

大都会。

Metropolis.

它们都是病菌。

They're germs.

病毒不是会让人生病吗？

Don't viruses make you sick?

有些会，但土壤里的大多数微生物对人类都是无害的。

Some can, but most of the germs in soil are harmless to humans.

它们都在忙什么？

What are they all doing?

这其实是土壤形成的下一步。

Well, this is the next layer of soil making.

你的苹果核被虫子吃了，虫子排泄之后，微生物就开始分解这些排泄物。

Your apple core was eaten by bugs, and then the bugs booted out, and now the microbes are eating the poo.

真恶心。

Ew.

为什么？

Why?

因为这对它们的营养有好处。

Because it's good for their diet.

里面全是对土壤有益的物质。

It's full of good soil stuff.

等它们分解完，地上就会长出更多的草。

And then when they pull it out, it grows more grass.

没错。

That's right.

微生物把昆虫剩下的残渣分解成最基础的成分，比如碳、氮、磷。

Germs break down the leftovers from the insects into their very smallest parts, elements like carbon, nitrogen, phosphorus.

刚才说什么？

What was that?

听起来像打雷。

That sounded like thunder.

上面肯定下雨了。

Must be raining up there.

往后退。

Push back.

哎呀，全是泥水坑。

Oh, muddy puddles.

水也是造土的重要部分，来自雨水、河流，甚至山顶融化的雪水。

Water is another important part of making soil, water from rain and rivers and even melted snow from mountaintops.

经过很多很多年，它会把岩石一点点地分解成越来越小的颗粒。

Over many, many years, it breaks down rocks into smaller and smaller paces.

我们学过这个。

We've learned about that.

这叫侵蚀。

It's called erosion.

大石头会变成沙子、盐，还有更小的颗粒。

Big rocks turn into sand, salt, and tinier pieces.

这些叫做矿物质。

They're called minerals.

土壤看起来有点闪闪发亮。

The soil is kind of sparkly.

这些是岩石里的矿物质吗？

Are they the minerals from rocks?

对。

Yes.

它们是岩石中最微小的组成部分。

They're the smallest parts of a rock.

哇哦。

Woah.

真棒。

Cool.

这边发生什么了？

What's happening over here?

看起来所有的养分都在往这边聚集。

It looks like all the nutrients are heading this way.

小心点，尼吉。

Careful, Nij.

别被卷进……

Don't get caught up in the

帮帮我。

Help me.

那只巨大的地下蜘蛛把我缠在网里了。

The giant underground spider's got me in its web.

快自救吧。

Save yourself.

这不是蜘蛛网，Nij。

It's not a spider web, Nij.

这叫菌丝。

It's called hyphae.

你只是不小心踩进菌丝网里了。

You've just tripped over in the mycelium.

它不粘人。

It's not sticky.

你站直就行。

Just stand out.

哦。

Oh.

菌丝是什么？

What's mycelium?

就像真菌的根系一样。

It's like the roots of a fungus.

它们在土壤里蔓延，有点像树木之间的电话网络。

They spread through the soil and work a bit like a telephone for trees.

所以树木能互相交流？

So the trees can talk to each other?

差不多吧。

Kind of.

主要是分享养分。

It's all about sharing nutrients.

叮铃铃。

Ring ring.

鳄梨树来电。

Avocado tree here.

你好，埃薇。

Hello, Evie.

有什么可以帮你的？

What can I do you for?

有多余的氮吗？

Got any spare nitrogen.

当然有。

Oh, for sure.

我这儿正好有糖，需要吗？

Need any sugar while I'm at it?

不用了。

No.

谢谢。

Thanks.

我这边没事。

I'm free.

有益的真菌。

Helpful fungi.

谢谢。

Thank you.

谢谢。

Thank you.

我会尽力的。

I'd try my best.

不是你，尼吉，是那个真菌。

Not you, Nij, the fungus.

而且

And

这都是在培育土壤的一部分吗？

and this is all part of making soil?

是的。

Yes.

你还记得我说过土壤是一个社群吗？

Remember how I said soil is a community?

我们认识的每一样东西——蜈蚣、微生物、菌丝，它们都在一起合作，把养分在土壤里传递，维持整个系统的生机。

Everyone we've met, the millipedes, the microbes, the mycelium, they're all working together, moving nutrients through the soil to keep everything alive.

所有东西？

Everything?

是的。

Yes.

连我们也不例外。

Even us.

我们正被树根吸进去呢。

We're getting sucked up by a tree's roots.

就这么被吸上去了。

Up we go.

哇哦。

Woah.

嘿。

Hey.

我们又恢复到正常大小了。

We're back to our normal size.

我们现在坐在苹果树上。

And we're sitting in the apple tree.

所以我们回到了起点。

So we're back to where we started.

对。

Yep.

当树的根系生长在富含养分、菌丝和昆虫、有益微生物的健康土壤里时，水分会把这一切混合起来，让树木通过根部吸收。

When a tree's roots are in healthy soil that's full of nutrients and mycelium and bugs and good germs, water mixes it all together, and the tree can drink it up through its roots.

这正是让植物长得健壮、果实特别香甜的关键。

It's what helps to make really healthy plants and super tasty fruit.

比如苹果。

Like apples.

所以我的苹果核又回到了树里，帮助长出更多的苹果。

So my apple core became part of the tree again to make more apples.

对。

Yep.

不过这个过程很慢。

It's a slow process, though.

要形成几毫米健康的土壤，可能需要一百年，而且这跟地表发生的事情息息相关。

It can take a hundred years to make just a few millimeters of healthy soil, and it has a lot to do with what's happening on the surface.

你这话是什么意思？

What do you mean?

其实，土壤常常被当成普通的 dirt 来对待。

Well, soil often gets treated like dirt.

我们得像保护海洋和天空一样，好好照料我们的土壤。

We need to look after our lovely soil just as much as we look after the sea or the sky.

你可以把香蕉皮扔进堆肥箱，它会变成养分，帮助花园生长。

You can throw banana peels into compost, and it makes nutrients to help the garden so it can grow.

你可以养个蚯蚓箱，再放很多土进去。

Well, you could, like, get a worm farm and then put, like, lots of soil in there.

你可以种一株植物，拿些土把它好好地、轻轻地培好。

You can get a plant and get some soil and tuck it in nicely and smoothly.

真不错。

Lovely.

和土壤建立联系挺有意思的。

It's fun to have a relationship with soil.

这可能是园艺、堆肥，或者用土画画、捏泥巴。

That might be gardening or composting or using soil for painting or making mud pies.

所以，

So,

埃薇，土壤是由许多细小的岩石颗粒组成的。

Evie, soil is made from lots of tiny bits of rock

比如沙子。

Like sand.

还有闪亮的矿物。

And sparkly mineral.

混合着空气、水和大量的有机物。

Mixed with air and water and lots of organic matter.

苹果和玉米。

Apple corn.

树叶。

Leaves.

还有花苞。

And buds.

首先被蚯蚓、甲虫和马陆这些生物分解。

First, decomposes like worms, beetles, and millipedes.

把它们全都吃掉。

Munch it all up.

土壤的清洁团队是大豆。

Clean up crew of soya.

咔嚓。

Crunch.

咔嚓。

Crunch.

咔嚓。

Crunch.

咔嚓。

Crunch.

咯吱。

Munch.

咯吱。

Munch.

然后它们就把排泄物排出来。

Then they poo it out

哎呀，真恶心。

Ew.

用来制造一种叫粪壤的东西。

To make what's called frass.

粪壤。

Frass.

然后细菌和真菌等微生物会进一步分解它，变成更小的成分，比如氮和磷。

Then germs, like bacteria and fungi, break it down even more into even tinier stuff like nitrogen and phosphorus.

植物的养料。

Plant food.

营养物质。

Nutrients.

这些营养物质可以通过水和菌丝在网络中在土壤里传递。

These nutrients can then move through the soil with the help of water and mycelium.

就像树木之间的电话网络。

Like a telephone for trees.

真菌的助力。

Help for fungi.

这样就能长出更多植物，还能生成更多土壤。

Which helps to grow more things and make even more soil.

健康的土壤是一个丰富又热闹的生态系统。

Healthy soil is a rich and bustling community.

这简直是一个完整的地下世界。

It's a whole underground world.

它们拼命工作，维持着地面上所有生命的运转。

Working hard to keep everything on land alive.

这是ABC儿童播客。

This is an ABC Kids podcast.

想听更多精彩故事？请在ABC Listen应用的儿童专区搜索你喜爱的播客，或者发现新的内容。

For more awesome stories, search for your favorite podcast or find something new in the kids tab of the ABC listen app.