You're listening to Shortwave from NPR.

I have to admit, I tend to take dirt a little bit for granted.

It's something I think about mostly if I track it in on the rug or if I need to wash it

off the dog after we've gone for a hike.

So in honor of World's Soil Day, I am here in the backyard digging in the dirt.

In this handful of soil that I just shoveled up, you know, first glance, it looks exactly

like what you'd think.

It's brown and crumbly.

It's got some clay consistency because it just rained.

But as I start to break it apart and look closer, I see all sorts of things.

There are earthworms, there are little white bug eggs like caviar.

There's, you know, rotting little chunks of wood.

And then just this web of roots and fungi all twisted together.

If you put, you know, a handful of healthy soil, say a forest topsoil if you will undisturbed

on the palm of your hands and look at it, just think about how that amount of soil holds,

you know, up to 10 billion individual living things in it.

Wow.

Most 10 billion individual things can come from anywhere up to five, maybe even more thousand

different species.

So we're talking about not just a lot of life, but a lot of diversity of life.

This is Asmratt Asif al-Bahe, a professor at the University of California, Merced.

She's also currently serving as the director of the Office of Science, the Department of

...