Spotlight Earth
From the Ground Up
6/6/2025 | 16m 23sVideo has Closed Captions
This episode is from WHRO’s Spotlight Earth series. Watch this video to learn more about soil.
This video dives into the importance of soil, explaining how this often overlooked substance is crucial for life on Earth. You will learn why understanding and caring for soil is essential as you get “down and dirty” in this episode of Spotlight Earth.
Problems playing video? | Closed Captioning Feedback
Problems playing video? | Closed Captioning Feedback
Spotlight Earth is a local public television program presented by WHRO Public Media
Spotlight Earth
From the Ground Up
6/6/2025 | 16m 23sVideo has Closed Captions
This video dives into the importance of soil, explaining how this often overlooked substance is crucial for life on Earth. You will learn why understanding and caring for soil is essential as you get “down and dirty” in this episode of Spotlight Earth.
Problems playing video? | Closed Captioning Feedback
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Learn Moreabout PBS online sponsorship(uplifting music) Soil.
Dirt.
But it doesn't matter what you call it, as long as you understand that it's necessary for life on Earth.
We're getting down and dirty today on "Spotlight Earth."
This is Drishti Compost in Virginia Beach.
This nonprofit is taking much of what we throw away and turning it into nutrient-rich soil.
We'll have more on the science of this amazing place a bit later in the show, but for now, let's get more of the dirt on dirt.
Let's head over to the studio where my partner in grime is standing by.
What's going on?
Hey, Michael.
It looks like you'll be doing some laundry later.
While Michael is ankle deep in the dirty work at the Compost Center, we're doing lunch here at the studio.
I whipped up a batch of my mom's famous hummus dip, loaded with delicious ingredients.
And it's not unlike the Earth's soil, a beautiful mixture of wonderful ingredients.
Soil is the thin upper layer of the Earth's surface, and it's made up of several components, minerals in the form of sand, gravel, silt, and clay, organic matter like worms, insects, fungi, and decaying plants and animals, plus water and tiny pockets of air.
We call the decayed plant and animal matter humus.
It is the primary source of nutrients for plant growth.
But don't confuse that humus with my chickpea hummus.
(Jarrell munching) Needs more pepper.
Just like how a recipe might differ from family to family, soil composition is unique to individual ecosystems.
In deserts with low rainfall, the soil will be sandy and dry.
Along rivers, you might find high-moisture silt-clay mixture.
Each location soil provides just the right proportions of organic matter, minerals, water, and air needed for the plants in that ecosystem.
If you take a core sample, you can see the different layers of the soil.
Each of these layers is called a horizon.
The combination of a soil's horizon is called a soil profile.
The two top layers of the soil are labeled O as in organic and A refers to the topsoil.
These two layers are what supply primary producers, like plants and algae, with the nutrients they need to grow.
There are many ways to categorize soils: by their color, mineral content, or profile.
One of the easiest ways to identify soil and its components is by taking a soil sample and analyzing its texture.
Just like my hummus, I like my soil chunky.
(hands rustling) Let's join Hails in the lab to learn how to sample soil.
Welcome to the lab.
Today, we're gonna be conducting soil sampling and soil texture analysis.
The United States Department of Agriculture categorizes soil into 12 identified texture classes.
These texture classes are determined by the proportions of clay, sand, and silt in the mineral part of a soil sample.
The words clay, sand, and silt actually refer to the size of the mineral particles in the soil.
Clay particles are so tiny that you can't see them individually.
Silt is the size of dust, like what you see floating in a ray of sunshine.
And particles that are sand size are .05 millimeters to two millimeters big.
Anything bigger, we call gravel.
The ratio of these particles is what determines the soil's texture, which refers to its water-holding capacity, permeability, and soil workability.
In this scientific investigation, we're going to measure the amount of clay, sand, and silt in a soil sample.
Then we're going to use a tool called the Soil Textural Triangle to identify and classify the soil sample.
I've gathered all the materials: a glass jar with a lid, two dry erase markers, a ruler, the stopwatch app on my phone, some lab trays, 15 milliliters of powdered laundry detergent, water, and enough soil from a local source to fill the jar 1/3 of the way full.
This soil was collected right outside the lab here in Norfolk.
(lighthearted music) We're going to need to break up the big clumps and remove all of the rocks, dried leaves, sticks, roots, things like that.
So I'm gonna break it up with my hands and then sift through it.
(lighthearted music continues) Okay, I think that looks pretty good now.
Next, I'm gonna fill the jar 1/3 full with soil.
(lighthearted music continues) And I need to fill the remainder of the jar with water, leaving space at the top.
(lighthearted music continues) Next, I'm gonna add 15 milliliters of powdered laundry detergent.
Once I have that in there, I'm gonna add the lid and shake the jar vigorously for three minutes.
(playful music) (water sloshing) (Hails exhaling heavily) Now, I'm going to place the jar on a level surface and set the timer for one minute.
Now that things have settled in the jar a bit, let's add a mark and measure the first layer that appears on the bottom of the jar.
(bright music) It looks like it's measuring about 2.0 centimeters.
Now, this is the coarse sand.
We do have to wait two hours to measure the next layer.
The next settled layer is the silt layer.
Let's mark the top of this layer and measure between the first line and the new line.
(bright music continues) It looks like it's measuring about 0.9 centimeters.
(relaxing music) Now, the last layer takes a little bit longer.
We would need to wait 48 hours before that settles completely.
But fortunately, we thought ahead, and we pulled an identical sample a couple of days ago.
And this is what that looks like.
(relaxing music continues) Check out this last light-colored layer here.
That's the clay.
Make the mark and then measure between the silt line and this final line.
(relaxing music continues) (marker lid clicking) 0.4 centimeters.
And now, I need to measure from the bottom of the jar to the final line.
It measures 3.3 centimeters.
All right, that's it for measurements.
Now, a few calculations to determine the percentage of the hole each layer is using a standard percentage formula.
(hopeful music) So the sand layer height was 2.0 centimeters.
And the total sample height was 3.3 centimeters.
If we plug these figures into the equation, we find that 2.0 divided by 3.3 times 100 equals 60.6% of the sample, and that's sand.
If we calculate silt in the same way, 0.9 divided by 3.3 times 100, we find that the sample is 27.3% silt.
Finally, we'll complete the calculation for the clay layer.
(hopeful music continues) The sample is 12.1% clay.
Now that we know these three percentages, we can use the soil textural triangle provided by the United States Department of Agriculture to classify the soil.
Starting with clay, we find the area where it indicates 12.1% clay.
Clay, that's about 12.1%.
(gentle uplifting music) And then we match it with the area that indicates 27.3% silt and match them both with the area that indicates 60.6% sand.
(gentle uplifting music continues) (gentle uplifting music continues) (gentle uplifting music continues) It looks like our soil sample is sandy loam.
This type of soil holds water better than a lot of sandy soils and is often high in the nutrients that plants need.
If you took a soil sample from another location, you could use the same process to test that sample and determine its texture.
Soil is a precious resource, especially when it comes to feeding the planet.
Let's check back in with Jarrell in the studio and learn more.
That is some awesome science, Hails.
Soil provides foundation for plants to grow and animals to feed.
38% of the global land surface is used for agriculture.
About 1/3 of this is used as cropland, while the remaining 2/3 are meadows and pastures for grazing livestock.
However, topsoil is under threat.
The removal of native species, overgrazing, over-farming, and development can compromise soil, rob it of nutrients, and expose it to erosion.
And pollution can make the land unusable.
And while topsoil is technically a renewable resource, it builds very slowly.
It can take a year to build just one millimeter of topsoil in ideal conditions.
So what can be done to protect soil and help it stay healthy?
Farmers have lots of management techniques for conserving and enhancing soil health.
Crops such as legumes, like soybeans and alfalfa, put nitrogen into the soil so they're rotated seasonally with crops like wheat and corn, which strip nitrogen from the soil.
How you till and plow when you plant, how you irrigate, and how you leave the land to rest every few years also conserves and protects the soil.
Instead of deforesting for new development, we can rehabilitate existing structures and we can control development and industrialization to protect our precious and dwindling farmland.
Luckily for us, Michael is still knee deep in a solution to replenish our Earth.
Let's go back to Drishti Compost in Virginia Beach to learn how their company helped save the soil.
Time to get down and dirty here at Drishti.
I get a tour from a guy named Farmer John.
One, two, three.
He provides all of the hard work to make this process happen, and he provided me with a tour of Drishti Composting.
That's really good.
(enlightening music) (faint tractor whirring) I may be the only person you know who gets excited when I see manure and food scraps.
(chuckles) And I have been a farmer for the past 25 years.
Now I only make compost.
Basically, what we try to do is mimic nature.
For example, right now, we're having an issue with phosphorus.
Some people say we may be running out of phosphorus.
It's very important for chemical farmers.
I can capture that phosphorus in all the food scraps that come here.
We were farming an organic farm for several years.
Most of the product was going right to our restaurants and other local restaurants.
When you start dealing with chefs, you know, you're a restaurateur, they're restaurateurs, but you're also growing the food, then they really start listening to you.
(lighthearted music) Our restaurant, it's called Prosperity Kitchen & Pantry.
Mainly a bakery, but we make pizzas, we make sourdough bread, but we use mostly local produce, and herbs, and stuff growing from round here.
Every bit of our scraps, including eggshells and everything, goes back into the compost pile.
So it's hundreds and hundreds of pounds, you know, over a course of a couple days.
There's a major problem with where we put all of our waste these days.
And we know that in not just Virginia Beach, but cities across the world, there's not any room left in landfills.
And there's no point in putting all these food scraps inside there that could be making really good healthy soil.
(lighthearted music continues) So what do you do?
Do you bag it up and sell it?
We do bags and we sell by the yard.
So I can fit two yards in my truck and have a trailer that has five-yard capacity.
The good news is it is always growing.
Regenerative, organic farming, composting is slow, but it is growing every year, and there are opportunities.
(lighthearted music continues) Are there any incentives at any, at a local, state, or federal level that are happening right now with this?
They are starting.
They're just starting to incentivize some of that.
But for me, 'cause I'm not a paperwork kinda guy, I'm a farmer, paperwork is, how do I say it, not my favorite thing.
(Michael chuckling) We're working with the City right now on trying to get them to come up with some sort of program to incentivize restaurants to divert all of their scraps 'cause right now, we're basically asking restaurants, "Hey, can you do this?
'Cause it's the right thing to do."
That's difficult for a small business.
Takes some time to create, but we hope that Virginia Beach can be one of the first.
(tractor whirring) I know that using compost makes this a good tomato.
I'm inspired and planning to do my part to help by putting together a composting project in my own backyard.
Thanks again to Kevin and John for talking to us about composting.
It's good, clean fun in the Virginia Beach mud.
From that to this.
During our interview with the folks at Drishti Compost, they mentioned that they get their organic food scraps from, among other places, food trucks.
Well, the truck behind me, The Coop Gourmet Burritos, is one of the trucks that lends its scraps to Drishti.
We wanted to give them a shout-out and try some of their awesome food.
(bright music) It's so good.
So remember, nutrient-rich soil is one of Earth's most precious resources, and composting is a great way to replenish those nutrients back into the earth.
Thanks for rolling around in the mud with us.
See you next time on "Spotlight Earth."
(bright music continues) (scene thudding)

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Spotlight Earth is a local public television program presented by WHRO Public Media