Bret Davis runs a 3,500-acre family farm in Delaware, U.S. state of Ohio, which grows corn, soybeans and wheat. Thanks to a crop-friendly weather across the Midwest this year, his farm has a good harvest. However, that could not spare him from worries.

Like many farmers in the country, Davis is concerned about the trade disputes that Washington started earlier this year as well as counter measures from its trading partners, including additional tariffs on U.S. agricultural exports.

"For us to survive as farmers, it's going to be pretty tough," Davis told a town hall meeting recently held in Columbus, Ohio's state capital.

The United States is a major agricultural producer and exporter, whose crop production far exceeds domestic needs. The tariffs from other economies on U.S. agricultural products are impacting its exports, causing concerns about oversupply and price decline in the country.

For instance, soybeans, a major U.S. agricultural product, have witnessed a significant drop in exports in recent months and prices fell to their lowest point in nearly a decade this summer.

Davis said that he cannot lock in the next two to three years if soybean prices were to maintain that level, which would threaten his ability to pay back his creditors and the families that work for him.

As to the subsidies on U.S. agricultural products proposed by the federal government months ago, Davis said they are "nothing but a band-aid."

In the neighboring state of Indiana, Brent Bible and his wife co-own a corn and soybean farm with another couple. He told an event in Indianapolis earlier this month that a drop in soybean prices between 15 to 20 percent would translate very quickly into a loss for him as his farm only keeps a margin of around 10 percent.

"We don't operate in a large margin and we are similar to other small businesses," Bible said. "If we can profit somewhere in the 10 percent range on our crop year over year, we can have a return on investment. We would feel like we are doing pretty good."

Bible said the tariffs have taken their business from what looked to be a very profitable level and some farmers are even selling their crops less than what they invested to raise them.

"That doesn't sustain itself for very long at all," he added.

Besides concerns over his farm's operation, Davis is also worried about the impact of tariffs on the U.S. agricultural industry on the whole and the country's food security.

He said the United States' plentiful, sustainable food source relies on free trade with the rest of the world.

Analysts said overseas buyers and consumers provide price support and allow U.S. farmers to continue farming at a profitable rate. If they could not sell their crops overseas, it would be difficult for them to invest in future production, endangering normal rotation and even domestic food supply.

Some U.S. farmers market their crops up to three years ahead. To them, long-term contracts and predictability in international trade are key to sustaining their farming activities and operations.

To expand the global market, Davis traveled to around 40 countries and regions and talked to buyers in person about his crops. Some visited his farm for assessment.

"We have very good relations back and forth," he told Xinhua, proud of farming and his products.

"We just want to make sure that the markets are open and that you can buy that product," he said.

Both Davis and Bible were speaking at town hall meetings held by a group of trade associations as part of a national campaign against tariffs. Called "Tariffs Hurt the Heartland", the campaign highlights the negative impact of tariffs on U.S. farmers, manufacturers, workers and consumers and the benefits of international trade to the U.S. economy.

"These things have very real consequence for businesses," Brian Kuehl, executive director of Farmers for Free Trade, said in Indianapolis. "It's happening everywhere."

Davis, the fifth generation owner of his family farm, said he hoped that the business can be passed down to future generations.

"It's not just a livelihood but also what our family does," he said. "We've got too much invested in this business to walk away."