Sitting in a combine, hour after hour, gives Blake Hurst a lot of time to worry. But it's not low corn prices he's fretting about, or the damp fog that's threatening to turn to rain.

Hurst is worried about NAFTA and what could happen to his farm, his family and his community if the U.S. pulls out of the trade agreement, as President Donald Trump has threatened to do.

"Here's this harm we're inflicting on ourselves. I feel like I should be able to do something about it. And I can't," said Hurst, who is also the president of the Missouri Farm Bureau.

"This isn't the difference between vacationing on the Riviera and not — this is the difference between our farm surviving or not."

The Hursts harvest corn on their four-generation farm. They export the corn to Mexico, which is a partner with Canada and the U.S. in NAFTA. (Lyndsay Duncombe/CBC) Four generations of the Hurst family have farmed in northwestern Missouri, near Tarkio. They have 6,000 acres of corn and soybeans, half owned, half rented. It's hard to know exactly where all their production goes, but much of the soybean crop ends up in China, and corn is exported to Mexico.

The concern is that without the NAFTA agreement between the U.S., Canada and Mexico, tariffs as high as 15 per cent on corn will return. And that, says Hurst, will turn a razor-thin profit margin to a loss.

"Of course the response you get when someone talks about trade and how it affects agriculture, the typical response is, 'Well, y'all voted for Trump, you deserve what you're getting.' That's sort of tough."

Tough, but also true. Three-quarters of voters in Atchison County, where Hurst farms, voted Republican in the 2016 presidential election. That includes Charlie Hurst, Blake's 83-year old father. He wasn't thinking about NAFTA when he cast his ballot, despite Trump's many calls to get rid of the agreement.

"I hope when all's said and done, he won't upset agriculture that much," said the elder Hurst, taking a quick break from combining.

"But you never know what will happen here. We're a long way from Washington."

A $13 billion warning

The hope that Trump's anti-trade talk was bluster is turning to panic in the U.S. agriculture industry.

This week 168 farm organizations and businesses wrote to all 50 U.S. governors arguing that leaving NAFTA would cost more than 200,000 jobs and $13 billion in GDP.

Just giving notice to withdraw, which would put negotiators on a six-month deadline, would have consequences for farmers. The letter warns, "Contracts would be renegotiated or cancelled, sales would be delayed or lost altogether, able foreign competitors would rush to seize our export markets."

Warren Erdman, executive vice-president of Kansas City Southern Railway, says, 'We remain optimistic that things will get worked out, simply because it's so critically important that they do.' He sits in the Harry S. Truman rail car, in which the former U.S. president used to ride. (Lyndsay Duncombe/CBC) Negotiators from the three countries are expected to meet again in mid-December for another round of talks. This whole renegotiation was sparked by Trump's denunciation of the trade deal.

One company with much at stake is Kansas City Southern, which owns and operates railways in the United States and Mexico, a complicated web of commerce so tied to trade that many simply call it The NAFTA Line. Grain from the Midwest goes south; vehicles and other finished products head north.

In an interview at the company's headquarters in Kansas City, executive vice-president Warren Erdman warned this latest round of NAFTA negotiations could be bumpy.

"This is a very big deal for our continent and for our country," he said. "It really comes down to remaining competitive in a global economy. We remain optimistic that things will get worked out, simply because it's so critically important that they do."

Just like the farmers: the railway seems to be holding out hope that the tough trade talk is posturing and ultimately, their industry and their bottom line won't suffer.

Blake Hurst's nephew, Dallas Hurst, holds kernels of the farm's corn. (Lyndsay Duncombe/CBC) "Sometimes the negotiations can establish positions that might be more severe than what ultimately is agreed to," said Erdman. "But there's no way of knowing that until we reach the final results."

Despite this uncertainty: many farmers still support the president. When Trump chose Springfield, Mo.,to launch his tax reform plan, Blake Hurst went to the rally. The president's speech, he said, was eloquent.

"Talking about how important it is for U.S. business to be competitive, and how tax reform would make that happen. So that's pretty good stuff. That's pretty exciting, and I agreed with it."

But then Trump mentioned NAFTA. He called the deal terrible and horrible.

"From my perspective, he's incorrect," said Hurst.

Hurst points out Trump made that speech at a factory that manufactures industrial fans. But the factory is surrounded by farms.