Coming up as the world prepares to make a climate deal, we look back on the first stirrings of sustainability.

In the late 60s and early 1970s, people were beginning to think that we were in the midst of an environmental crisis.

And the incredible world of soils.

I wish everybody could see what we see when we look through a microscope.

There might be thousands of very, very different nematodes, mites, microarthopods.

Plus a new technique promises super high-res ultrasound.

This is the nature podcast for November the 26th, 2015.

I'm Kerry Smith.

This year, 2015, is the International Year of Soils, a muddy subject, but an important one.

Soils perform a whole plethora of functions, from the obvious like giving plants a place to grow, to

the less so, like purifying and storing our water. Soils can even keep our bodies healthy.

They contain millions of constantly interacting organisms, including pathogens that infect plants

and animals, humans included, of course. The way we manage our soils can put these delicate

interactions out of whack, potentially leading to the outbreak of disease. In short, the changing

health of soils has direct consequences for the health of, well, us. Nowa Baker spoke to Diana

Wall from Colorado State University, who has written a perspective article on the subject of

soils and health. Here's Diana. There have been significant advances in our knowledge below our feet

just in the last 20 years. I mean, it is a rapid advance in knowledge of who's under our feet

and what they're doing and how they work in factories

and food webs, so to speak, to provide a lot of benefits to all of us.

So what kind of things are you talking here living underneath our feet?

Oh, there's some, I wish everybody could see what we see when we look through a microscope.

...