How does soil get made?
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From the brains behind Brains On, this is the Moment of Um. Moment of Um comes to you from APM Studios. I'm your host, Nico Whistler, and welcome to my garden. Today, I'll be planting some carrots. Let's see. The packet says to plant the seeds a quarter inch deep and one inch apart. Okay, here we go.

What's happening? It's so dark in here. Can anybody hear me? I can hear you. Ugh. Tastes like dirt. But it smells really nice. It's so squishy. What is even in this soil? A creature is approaching! It has no-- Get back. Get back!

Don't worry, little seeds. That's a worm. It won't hurt you. Actually, worms are a sign that the soil you're in is healthy. And as far as what the soil is made of and how it's made, you're not the only ones wondering that. Listener Teo had the same question. Hi, my name is Teo.

And my question is, how does soil get made? We went down to the farm to get the answer. Basically, soil is made when rocks and organic materials break down over time and combine. My name is Angel Papineau, and I'm a farmer in Philadelphia. If you imagine...

a, like, section of the forest. So underneath the forest floor, like way down deep towards the center of the earth, there's a piece of rock called bedrock. And also on the surface of the ground, there are bigger rocks and stones and boulders. And so over really long amounts of time, the wind and the rain and tree roots are breaking down

the rocks that are on the surface and breaking it down into lots of little pieces. Over an even longer period of time, that bedrock underneath us also has been eroding and particles from that are also coming off and mixing in with the whole soil mixture.

On that same patch of land, there also could be leaves that fell from trees, or a hiker could have dropped an apple core or an orange peel. Maybe an animal died or an animal pooped. And all of those different things are all organic materials. And so over time, those break down. If you want soil that's healthy for growing plants, for eating, there are a couple of different things that you can look for.

First would be to look at the color of the soil. Usually a dark brown, almost black color means that your soil has a lot more organic material, which is really good for growing fruits and vegetables. You could also smell the soil and see if it has like a sweet and earthy smell, which is obviously not like a specific thing and it's a little hard to describe, but it certainly shouldn't smell bad or stinky.

Because that means that there are still things rotting and decaying in the soil, and you don't want things actively breaking down. ♪

Um... The worms tunneling around in there help break the soil up, which will mean your roots have more space to move and spread. So, how are you doing in there now? You finally settling in? Yep, we're good. I obtained the worm. We're gonna see the world together. Paris, Lagos, Kathmandu. There's no better way to travel than on wormback. Can we get some water in here, please? Thirsty! Thirsty!

If you like this episode, take a second to subscribe wherever you listen to podcasts. And if you want to learn even more about goodies from the ground, check out the Brains On podcast, where we have a whole episode that takes a fascinating look at fungus and mold. If you have a moment of unquestion, we'd love to help you answer it. Drop us a line by going to brainson.org slash contact.

See you next time and the next day and every weekday. Until then, um...