Farmers are mostly pleased with President Trumps first yearbut were also worried about what comes next.

Our general approval was on display last week, when the President addressed the annual convention of the American Farm Bureau in Nashville, TN. I was at the convention for his remarks, which were often interrupted with loud applausemost obviously when he mentioned his victory on the tax bill, which includes a reform of the estate tax that will make it easier for us to keep our farms in our families across generations.

That line earned a standing ovation.

We appreciate other accomplishments as well. The booming stock market improves our retirement savings. New opportunities for rural communities to receive internet access will help us stay connected with the world. And on reducing regulations, the president has been a great champion.

Many of you have endured burdensome fines, inspections, paperwork, and relentless intrusion from an army of regulators at the EPA, the FDA, and countless other federal agencies, he said.

Thats so trueand we appreciate his efforts to make it easier for us to farm. A perfect example is his repeal of the EPAs Waters of the United States rule. It sounds so nice. It sounds so innocent. It was a disaster, he said. The title was beautiful. Thats where it stopped.

More applauseand also laughter.

Yet our apparent good mood masked a tremendous anxiety: Despite these policy achievements, were worried about the Trump administrations approach to tradeand the possibility that a withdrawal from NAFTA will devastate our ability to sell what we produce.

President Trump spoke about trade only briefly, and what he said was vague: On NAFTA I am working very hard to get a better deal for our country and our farmers and our manufacturers.

Ill take a better deal. Everyone knows that NAFTA could use a few updates after nearly 25 years. We might also imagine improvements for agriculture, such as resolution of trade issues with Canada related to the dairy and forestry industries.

At the same time, we must recognize that NAFTA has been a boon for farmers and our customers. Under its provisions, our exports to Canada and Mexico have nearly quadrupled, to about $20 billion and $18 billion, respectively, resulting in total economic activity exceeding $107 billion according to the Center for North American Studies. Together, these two countries buy about one-third of all the products farmers sell abroad.

Our country cant afford to lose these marketsand thats exactly what could happen if the White House were to withdraw from NAFTA.

My hope is that the rhetoric of withdrawal is merely the presidents tough-talking way of achieving a better agreement. By threatening to abandon a trade pact that also benefits Canada and Mexico, perhaps hell win key concessions that American farmers will cheer as loudly as we cheered his estate-tax revisions in Nashville last week.

Our fear is that President Trump really will walk away from NAFTA, much as he quit the Trans-Pacific Partnership shortly after assuming office last year. The difference is that although TPP would have helped farmers, its benefits lay in the future. They are like a gift we wont receivea disappointment, but not a catastrophe.

The benefits of NAFTA, however, are in the presentand withdrawal would remove an important part of our livelihood. It would feel like a theft.

The problem is complicated by our high productivity during a time of low commodity prices. Last year, my farm enjoyed a record-setting yield. New technologies promise that soon well grow even more.

As much as we appreciate regulatory relief and tax reform, what we really need are markets: Unbroken access to the ones that we have now, and new ones that trade diplomats can open for us.

At the start of his speech last week, President Trump joked that he was disappointed to learn that his hosts were celebrating their 99th year as an organization. A hundred is so much cooler, he said. So Ill be back, I think. Next year, Ill come back. All right? Well come back.

His reception in 12 months will depend largely on what happens with NAFTA. If he wants the applause to continue, hell keep us in this trade agreement and make it even better.

The alternative is too grim to contemplate.

A version of this column first appeared January 16 at The Hill.