- Hi there, I'm Frank Graff.

How science created North Carolina's most popular crop, we'll visit a solar sheep farm, and go truffle farming.

We're harvesting science next on "Sci NC."

- [Announcer] Quality public television is made possible through the financial contributions of viewers like you, who invite you to join them in supporting PBS NC.

[gentle music] ♪ [gentle music continues] - Hi again, and welcome to "Sci NC."

Researchers at NC State developed the Covington brand of sweet potatoes, and that has helped make North Carolina the nation's top producer of sweet potatoes.

But as students from the UNC Hussman School of Journalism and Media show us, there are challenges on the horizon.

[gentle music] - [Student] It's harvest time again for sweet potatoes.

These Southern staples are a cultural icon of North Carolina.

The beloved vegetable unites people around the table, and support a huge farm industry.

- Right here behind me, we are in the middle of peak harvest.

It's a beautiful October day, we've got all of our guys out here making sure we get a beautiful crop into our storage this year, and we are ready for the 2023-2024 season, and ready to pack these potatoes, and send them on to their final destinations.

- [Student] These workers from Mexico came to North Carolina on a temporary agricultural employment visa.

They may stay as long as six months, as they fulfill jobs in the farming industry, which is facing a shortage of labor.

[gentle music] Taylor Hill is a third generation farmer at J. Roland Wood Farms in Johnston County.

Granddaughter of James Roland Wood, the company's founder, Hill grew up helping her family on the farm.

After graduating from North Carolina State University, she's been marketing and selling the family's crops.

- J. Roland Wood Farms.

To bring a new perspective to the table, especially with my own farm, I'm the youngest one here, and it's really nice to be able to bring a female perspective, but also bring a younger audience in perspective.

- [Student] Since its start in 1967, J. Roland Wood Farms now cultivates more than 1500 acres, producing up to 30 million pounds of sweet potatoes a year.

Statewide, the UNC Carolina Demography Program reports that in 2020, sweet potatoes added $375 million to North Carolina's economy.

That ranks as the state's third most valuable crop.

The top selling sweet potato variety was the Covington.

Crop Scientist Craig Yencho spearheaded North Carolina State University's efforts to develop the variety.

- Covington was a result of a long-term breeding program.

Before in the performance, until released Covington in 2005, the major competitor for Covington was a variety called Beauregard.

The thing that Covington did better than Beauregard was that Covington performed year in and year out, yielded well in a wide range of situations and circumstances, and packed out much better, and that's really what helped Covington succeed.

- [Student] The Covington variety now accounts for 90% of sweet potatoes grown in the state, but crop scientists are looking to improve it.

To help in that effort, farmers can volunteer to plant new varieties that Yencho and his team think have potential.

Scientists track the crop's success in the field.

The partnership with farmers is a critical piece to the breeding program's success.

Another important piece includes guidance from the Horticultural Crops Research Station in Clinton, where Hunter Barrier connects farmers with crop scientists.

- We fail so that farmers don't have to, so we try to solve production challenges, and give growers answers.

- [Student] Shortly after switching to the Covington, J. Roland Wood Farms opened a new packing facility in 2017.

After harvest, workers sort sweet potatoes into two different grades, and then pack them into wooden crates, before they go into storage.

There, sweet potatoes undergo a process known as curing, that turns starches into sugars, giving them their distinctive sweetness.

Although the Covington variety has brought Hill and her family success, she anticipates challenges ahead.

- Covington, it's had a good run.

It's doing good, but it's slowly starting to become a thing of the past.

[camera shutter clicking] - One of the big challenges right now in sweet potato production is a new pest in North Carolina, called the guava root-knot nematode, and it has potentially devastating consequences to our international markets.

- [Student] The guava root-knot nematode is an invasive worm that comes from the tropics.

The pest feeds on sweet potatoes' roots, and deprives the crop of needed nutrients, hurting crop yields.

Yencho says a top priority for his team is to produce a new variety, with quality similar to the Covington, but with the resistance to the nematode.

While scientists are testing potential new varieties, they encourage farmers to look for signs of nematode damage in the field, and report it to the North Carolina Department of Agriculture.

- It's still very strong, don't get me wrong.

In North Carolina, it's the biggest variety we grow, but they're definitely doing a lot of research to give us a new variety, and I'm excited to see what is gonna come in the next few years.

- [Student] In the meantime, workers are busy getting the current sweet potato crop ready for market.

This truck is leaving the Benson packing facility in Johnston County, for its 12-hour trip to a New York City wholesale market.

The sweet potatoes could be in grocery stores the next day.

- I grew up around agriculture, of course.

I grew up here on the farm, but as I got older, I realized how much I loved being here, and how much it was good for me to be here with my family.

Working with my family has been something I've always enjoyed all my life, and I plan to continue here, and I hope one day I can bring along a fourth generation.

[gentle music] - Truffles are a rare and expensive fungi.

They are a delicacy.

And as producer Evan Howell explains, truffles are difficult to grow, and it takes a special farmer to find them.

[playful music] - [Evan] This is Aki, he's a special dog with a very special skill.

It's so special, Aki was brought to North Carolina from Serbia.

- This is Aki, Aki is our truffle dog.

He is a Lagotto Romagnolo.

He had to have his passport.

He came in, changed planes, went to Washington, D.C., got off the plane, got on a van, and came to the farm.

- [Evan] That's right, Aki is a truffle dog, actually a truffle-finding dog.

But wait, what's a truffle?

- A truffle is the fruiting body of a particular kind of fungus.

- [Evan] Truffles have been around for centuries.

They've been used in dishes around the world, and are prized for their unique taste and aroma.

These days, foodies everywhere have created a kind of insanity around truffles, and that makes Aki's special skills all the more valuable.

[playful music] - To get him to work, I have to give him a command of search.

Search, search.

[Aki sniffing] Find the truffle, find the truffle.

He smells the truffle, you can tell it, and then he'll paw it, he'll paw it.

[playful music] Buddy, tree.

- [Evan] At around two years old, Aki is a veteran.

And on any given shift, he'll find dozens of them growing around the roots of these loblolly pine trees in the northern part of the Piedmont.

And yes, when he finds them, he gets treats.

- [Walter] Eh, eh, eh, eh, good dog, good dog, good boy.

Today he's getting pepperoni.

- [Evan] Jeffrey Coker is another one of Aki's colleagues.

He's a plant scientist, who found himself in the truffle business about 10 years ago.

- In nature, they're biologically designed to attract animals to eat them.

So they're sitting in the ground, and if you're in the ground, how do you lure animals to you?

You have to put off an aroma, a really strong aroma.

So that's what truffles are doing.

They're trying to send their spores elsewhere, to reproduce fungi, using a really strong aroma.

- White means October, we found this truffle in October crowning.

- [Evan] Growing truffles is difficult.

People in the United States have been trying to do it for a long time, but the conditions need to be just right.

- The truffle that we're growing is called the Bianchetto truffle.

The scientific name is tuber borchii.

It grows in in Italy, France, Spain.

It's a European truffle.

Our stock comes primarily from Italy.

Whenever you find one, it's just like dealing with an iceberg.

You never know how big it is [laughing], until you pull it back far enough.

- [Evan] There are forage truffles, which are found in the wild.

And then there are farm truffles.

Here at Burwell Farms, they've built and maintained an orchard specially designed to produce them.

- The biggest reason why our farm works is really just the basic biology, having two robust species, having a very robust tree, partnered with a very robust European truffle.

- [Evan] The tree he's talking about here is a loblolly pine, which is found everywhere in the Piedmont.

The region also has a balanced soil, made up of sand, silt, and clay.

The trouble is pines grow well in acidic soil, but truffles don't, and both tree and truffle need to grow in this orchard.

So Coker's team is bringing the acid levels in the soil down to help the truffles.

Meanwhile, the truffles help the pines by carrying water and nutrients into their roots.

It's a match made in, well, North Carolina.

- Good boy.

- So again, it's that powerful symbiosis, is what allows the pine trees to exist in the soil conditions that we create.

[playful music] - [Evan] Besides the soil challenges, here's the other thing about truffle farming, it takes a long time, and this farm has been growing for a little over 10 years.

But they're also in the business of cultivating young trees to expand their own stock, and sell to other farms as well.

Coker's team places tiny truffle fungi on the roots of these baby pines in a process called inoculation.

- So this is our greenhouse.

Behind me are thousands of young loblolly pine trees that we've placed the truffle fungus on the roots.

As you can see here, there are lots of little white fungal threads all through this root system.

And this pine tree could successfully be placed in an orchard today, that was properly prepared, and would be producing truffles within a few years.

- We actually sell out before our season even starts.

- [Evan] Truffle growing may be slow, but the clock starts ticking once a truffle is taken out of the orchard.

Truffles lose their taste and aroma about one week after they're harvested.

Kate Dinges says that doesn't give her much time to clean and package the truffles for delivery to their clients.

- Our turnaround time is very short, so we can't get them a truffle a few days in advance, because it's starting to go downhill from the day we take it out of the ground.

So we normally get the truffle out of the ground, say on Wednesday, and then Wednesday morning we clean, Wednesday afternoon, we ship that out, and they get it the next morning.

And latest, I would say three, four o'clock.

[playful music] - [Walter] He found about 40.

- [Evan] Aki here can sniff out a few hundred truffles a day around the orchards Burwell Farms operates.

Back in the day, farmers used pigs to do the job, but dogs won out.

- [Walter] It was hard to get a 400-pound pig to keep it from eating the truffle.

- [Evan] Even with science behind this process, there's no guarantee these trees will yield a quality truffle.

Again, they're notoriously difficult to grow, but thanks to Aki, finding them is not an issue.

[Aki barking] - The United Nations reports that 3/4 of the world's food supply is pollinated by bees.

Producer Rossie Izler has more.

[gentle music] - [Rossie] When you picture a bee, it's probably the honeybee you're thinking of, and that makes sense.

[bees buzzing] We raise millions of these honeybee colonies in the U.S., because we rely on them to pollinate 1/3 of all our commercial crops, things like almonds, berries, and squash.

Plus, they are cute with their fuzzy little appendages.

But here's the thing, honeybees are just one of the thousands of bee species worldwide, and they tend to be the poster child for bee conservation, and that's really bad news for the thousands of bees you've never heard of.

Let's talk about wild bees.

[playful music] - So as far as bees go, they're a extremely diverse group of organisms.

There are more than 20,000 different species of bees in the world, over 4,000 in North America, and right now in North Carolina, we think we have about 564 different species of bees.

- [Rossie] But more than half of these species are declining, and one in four are at risk of extinction.

Meanwhile, honeybees are domesticated.

We know how to raise them.

So rallying conservation support behind the honeybee is kind of like rallying behind the house cat, when you're trying to save the critically-endangered West African lion, or trying to save the chicken, when you're concerned about declining bird populations.

What's really concerning are the thousands of bees we don't know much about.

Some of these bees have specialized relationships with specific plants.

Without them, we lose those plants, and the animals that depend on those plants.

Bee loss could damage countless delicate ecosystems, and ripple through the food chain.

- So bees get sick just like us.

They can be infected with viruses, as well as gut parasites.

- [Rossie] This is Dr. Hannah Levenson.

She's a community ecologist, and she's working on solutions to the pollinator problem.

- But I think one of the biggest ones is the habitat.

I think that when we add habitat back into the environment, that can have immediate impacts on bee populations working to support them.

And so that's a big one that I think we can focus on.

- [Rossie] The irony of this situation is that we're growing plants that need pollination in an incredibly tough environment for bees, and that is monoculture farming.

It's highly mechanized, incredibly efficient, and responsible for feeding the eight billion-and-counting people on this planet.

But these homogenous landscapes, and the pesticides that come with them, aren't great for wild bees.

The same is true for sprawling housing development.

- So bees need nesting habitat, where they build their nests, lay their eggs, raise their young.

And they also need forage habitat, where they collect food resources.

- [Rossie] Honeybees and bumblebees are cavity nesters, but the vast majority of bee species live and lay eggs underground.

So disturbed land, whether it's for farms or subdivisions, means less habitat for wild bees.

- So as we clear areas to develop and build, there's not gonna be the bare ground the bees need.

There won't be the woody materials that bees need.

And then if there's no flowers around, then there's no pollen and nectar for bees to collect.

- [Rossie] But Hannah is documenting a solution to this problem, and discovering that even a little effort can go a long way.

This is an experimental farm.

It's part of NC State's Agriculture Extension Network.

A few years ago, these research sites were required to add pollinator-friendly flowers along the edges of their crops.

It's a throwback to the ancient hedgerow, which were used for centuries in Europe, to divide agriculture fields and residential properties.

- We wanted to see what actually happened to the bee community when this habitat was added into the environment.

Was it actually doing what we wanted it to do?

Was the effort we were putting in providing enough resources to bees, and could we come up with some recommendations for how to improve that habitat?

- [Rossie] The short answer, it worked.

Even adding small plantings increased both the number and the diversity of bee populations.

Hannah even found a very rare species of bumblebee, and there are other benefits to these plantings too.

- So a lot of the research stations planted this in areas that were otherwise unusable, or weren't suitable for certain crops.

So if you have an area that just is sitting, you could plant this seed mix there.

It also provides reduced maintenance during the summer.

So while the plants are active in providing habitat for all of our wildlife, you don't have to mow, you don't have to do weed maintenance.

- [Rossie] Hannah says this research applies to non-farmers too, basically anyone who has access to a yard, or even a window box.

Start small, get a local flower seed mix, and leave the flowers alone after they die.

- So a lot of people have the tendency to when the plants start dying, it doesn't look as nice, to cut it back.

But we would recommend actually leaving it as long as possible.

And there is evidence that organisms that we care about overwinter in this sort of habitat, so we need to leave that for them all winter, and into the spring.

But then beyond that, start where you can, add little bits at a time, and you can always work up and expand it.

Even when people are doing it and it's not perfect, we still do get a benefit to the bee community.

- Producer Michelle Lotker now takes us to a farm that combines the future with the past.

[serene music] - I think you can only disobey the laws of gravity so long.

Solar really is the most economical gravitational force for energy generation.

Solar is inexpensive, it's easy to put almost anywhere, and it makes an ideal place where agricultures can also thrive if you plan early in the design and layout phase.

Whoo, come on.

Whoo, come on, big mamas.

Development, in general, can really occupy a lot of what was previously farmland, and that's not necessarily true with solar farming.

This site, for example, wasn't being used for agriculture at all, but after we finished solar, now all 200 acres are put into agriculture.

The word that's been used to describe what we're doing here is agrivoltaics.

The agri part means agriculture, where we're using livestock to maintain the vegetation underneath the solar panels.

The voltaics part of that is photovoltaics, where we're converting light into electricity.

[gentle electronic music] This is called the Montgomery Sheep Farm.

We use this as kind of a research station.

- We had to kinda prove that it really made sense to raise sheep on solar farms, and we've been doing that now for several years.

This is our innovation station, where we have school classes, we have farm dinners, and an educational place for people to come and stay, and see how it really works.

The model is we partner with local farmers where the solar sites are, and they bring their sheep.

After a while doing that, we figured we need a market for our lamb.

I grew up in Norway, and I grew up with lamb salami, that's a pretty common thing to have on the table.

We have the lamb salami, we have all different types of lamb cuts that's kind of hard to find other places.

We utilize the whole animal.

We do dog bones, for, you know, some of the bones.

It's really good for dogs.

And we do have a also a sausage, that's a garlic bratwurts, which is good.

We get a lot of positive feedback.

People enjoy coming out, see the farm, see the operation, come here, have dinner outside, meet new people, and enjoy a different type of food.

[serene music] - The Montgomery Sheep Farm has a 20 megawatt AC solar panel installation.

So during sunlight hours, we're generating 20 megawatts of power, which is, if you break that down into how much power the average home consumes on a yearly basis, that's about the same as what 3000 homes would consume of power.

That power is transported here to this substation, and you can think about it like water, right?

The water that's coming in these big pipes on transmission lines are looking at the substation, and saying, "Hey, do we need to add more water?"

If the Montgomery Sheep Farm has generated enough power that the bucket is full, then that power will go to the next town.

We're in the center of North Carolina in Montgomery County, and we are just on the edge of the town of Biscoe.

During daylight hours, the Montgomery Sheep Farm is basically filling up the local bucket here, so the power on that transmission line gets transmitted downline.

60% of the U.S. population lives east of the Mississippi, so putting a bunch of solar in the desert, and somehow transporting that to the East Coast doesn't make a lot of sense.

We're located 60 miles from Charlotte.

We're located 60 miles from Raleigh, 40 miles from Greensboro.

So in a sense, we're in a rural part of the state, but we're certainly not in the desert in Nevada.

So whatever we generate here is very closely linked to, you know, what people in the utility industry call our load centers, the larger cities where we need a lot of power.

[gentle music] Normally you'll see the sheep kind of attracted to being underneath the panels, because of the environment it creates.

In the winter, you're protected from snow, and rain, and whatnot, but in the summer, you're protected from the heat.

The solar panels do two things.

One, is they kind of mimic what trees do.

They create shade that lowers the temperature on different parts of the soil.

So underneath the solar panels, you have vegetation like clover and fescue, that don't normally grow in North Carolina in the middle of the summer.

And you can very clearly see that line where the sun hit during the summer months, and created this different type of grass, Bermuda or crab grass, or hot weather grasses.

But you've got this diversity in vegetation, which is good for their diet.

The waste of the animal was helping to fertilize the soil as well.

So before we had a solar farm, and before we had sheep, there wasn't much organic matter in the soil.

But now you see how thick it is?

So that's really good to regenerate the health of the soil.

It's a really neat ecosystem in a solar farm, because they have kind of the best of both worlds.

[gentle music] By 2016, we had the second most solar installed in the country here in North Carolina.

Because of some of the legislative and regulatory changes, a lot of the market that was here in North Carolina has moved to other states.

We've gone from number two in the country, now we're number four, and we're falling pretty fast.

So it's something that we need to get together with, and find a solution that allows us to generate the power we need, cleanly, affordably, and safely.

- And that's it for "Sci NC," I'm Frank Graff, thanks for watching.

[gentle music] ♪ [gentle music continues] ♪ [gentle music continues] ♪ - [Announcer] Quality Public Television is made possible through the financial contributions of viewers like you, who invite you to join them in supporting PBS NC.