AMNA NAWAZ: Among the many horrors of war, one lingers and kills for years, even decades afterward, land mines and unexploded ordinance.

Ukraine is now littered with land mines and bombs from both sides of the firing line.

The task of clearing those explosives is massive and complicated.

But a technological advancement tested in Oklahoma could make that job far easier in the breadbasket of Ukraine.

With the support of the Pulitzer Center, special correspondent Jack Hewson reports.

JACK HEWSON: Cautious steps into the farmland of Mykolaiv, Southern Ukraine, these soldiers are on dangerous ground.

In just over 18 months of conflict, Ukraine has become the most mined country on the planet.

In this liberated territory, these military engineers, or sapper, are practicing mine clearance the old-fashioned way.

It is a process of walking out in lines of about 50 meters at a time with a piece of rope behind you marking where you have been.

Even on a clear stretch, that will take 15 minutes at least.

And If they find something, then they are going to be there digging it out for significantly longer, then maybe blowing it up.

That's how long it takes just for 50 square meters.

You can see how big this field is.

It's going to take forever just one field, never mind the rest of the country.

More than 67,000 square miles of Ukraine is reportedly littered with land mines and unexploded ordnance, or UXO.

That's a landmass equivalent to Florida.

Tasked with much of the clearance of Ukraine's civilian areas is the Special State Transportation Service, or SSTS.

Sergeant Dymytro Savytsky tells us it's slow and dangerous work.

SGT.

DYMYTRO SAVYTSKY, Ukrainian Military (through translator): My squad leader, he had a traumatic amputation of his right leg.

JACK HEWSON: What goes through your mind doing this job every day knowing that something like what happened to your friend could happen to you?

SGT.

DYMYTRO SAVYTSKY (through translator): We realize that our citizens, children, and women will walk on these lands.

Even here, in the field, workers and combine harvesters are working, and people's lives depend on our work.

JACK HEWSON: Just down the road from this field, Oleksandr Kunitsa knows this all too well.

He was nearly killed foraging for mushrooms near his home.

OLEKSANDR KUNITSA, Injured By Land Mine (through translator): I don't even want to recall it.

There, I hit the plastic mine.

Considering the things I saw doctors extracting from me, I hit the PMN-2, an anti-personnel pressure high-explosive mine.

The only other thing that I remember is that I asked those guys who were carrying me out of there to shoot me.

I'm used to walking on my two legs.

JACK HEWSON: The area had supposedly been cleared several times.

OLEKSANDR KUNITSA (through translator): It is very difficult to find such mines.

It's 30 percent likely that you will find this mine and 70 percent likely that you will hit it.

Even if you run a metal detector over that mine, it won't see it.

JACK HEWSON: This constant background anxiety that your next step could be your last leaves Oleksandr's community on edge.

OLEKSANDR KUNITSA (through translator): During this last month, there have already been three cases of people hitting mines.

I was the most lucky because I remained alive.

JACK HEWSON: It's not just lives that are threatened by mines, but livelihoods too; 19,000 square miles of Ukraine's agricultural land has been polluted by UXO.

Mykolaiv commercial tomato producer Furman Konstantin is unable to use 85 percent of his fields.

FURMAN KONSTANTIN, Farmer (through translator): This is a disaster, but what can we do?

We are trying to work with what we have.

JACK HEWSON: He's lucky that the army has already cleared 4,500 acres that he has now planted, but manual demining is agonizingly slow.

Agriculture accounts for 41 percent of Ukraine's exports, and rapid demining will be vital for the country's economy.

FURMAN KONSTANTIN (through translator): I mean, demining the territory on foot without special machines will take hundreds of years.

That's why I believe that using technology for demining is the only way to quickly restore agriculture in our country.

JACK HEWSON: Konstantin is right.

A recent study estimated that it could take more than 700 years to clear Ukraine's minefields with the resources it currently has.

But new technology brings hope.

Two young American scientists are in the final stages of testing a machine learning algorithm that locates mines and UXO without having to endanger human life.

JASPER BAUER, Chief Scientist, Spotlight: The demining web application we have developed is called Spotlight because it's going to find different items from the sky, similar to a spotlight would.

GABRIEL STEINBERG, Developer, Spotlight: The mines are very small.

And often, in high vegetation, it's impossible to see them unless you're standing right over them.

The good thing about drones is that they're always right over the mines.

JACK HEWSON: Meet Jasper Bauer and Gabriel Steinberg.

Their yearslong work and research has led to this application, which can be harnessed with commercially available drones.

JASPER BAUER: All you have to do is upload the imagery to the platform and it feeds it through the A.I.

detection.

And what the A.I.

detection does is, it scans all the images that you have uploaded, it's trained on what the munitions and mines look like, and it will draw boxes and identify them and provide locations as well.

So our platform is designed to be very easy to use for deminers and other people, potentially farmers who have contamination in their field.

JACK HEWSON: We travel to Chernihiv in Northern Ukraine, an area occupied by Russia at the start of the war, where the application is being prepped for real-world use.

This is a field test for Spotlight technology on the M42 American cluster munitions that have recently been shipped here and will need to be cleared from Ukrainian land at the end of this war.

FRED POLK, Operations Director, Spotlight: So this is our last test, so we're trying to break it.

JACK HEWSON: Operations director Fred Polk and software engineer Artem Motorniuk are overseeing this final test.

FRED POLK: And with the cluster munitions being employed, it's important that the Ukrainians have the possibility of cleaning up after themselves.

JACK HEWSON: In addition to unexploded cluster submunitions, the technology can also identify around 100 different kinds of land mines and other ordnance.

ARTEM MOTORNIUK, Software Engineer, Spotlight: So, now I'm getting data from S.D.

card from my computer, uploading the data on Spotlight, the application, and then we will have results.

JACK HEWSON: How much more effective is this?

ARTEM MOTORNIUK: Oh, it's very effective, I guess.

It will save a lot of lives.

JACK HEWSON: Since this successful test, Spotlight has been used to clear its first active minefield in Ukraine and is ready for deployment, pending approval from the Ukrainian authorities.

Perhaps this app, dreamed up and tested on the American Great Plains, will save the lives and limbs of Ukrainian civilians.

As for Oleksandr, whatever comes, he does not dwell on his misfortune.

OLEKSANDR KUNITSA (through translator): I will get a prosthesis, and I will be able to walk again.

And, as they say, movement is life, or the road is life.

JACK HEWSON: Now he keeps all of the remnants of war that he's found around his village, of which there is no shortage.

OLEKSANDR KUNITSA (through translator): I had an idea to make a sort of museum where we could educate people on how to protect themselves from mines and show them what they really look like.

JACK HEWSON: Learning to cope with the threat of mines will be a grim reality faced by millions as they return to their homes in Eastern and Southern Ukraine, land they have won back, yet tainted by the deadly legacy of war.

For the "PBS NewsHour," I'm Jack Hewson in Ukraine.