The Farm Progress Show in Boone, Iowa is a vast event. Now in its 65th year, agricultural manufacturers show off their latest products to thousands of farmers attended. 

But this time, this country's largest outdoor farm event is taking place against the backdrop of concerns over trade tariffs. 

It is billed as a celebration of agriculture. But many farmers could be forgiven for feeling more somber this year. 

After the Trump administration imposed tariffs on various countries in recent months, many of them, in turn, responded with tariffs of their own, with farming a key target. 

US Secretary of Agriculture Sonny Perdue spoke at the event and acknowledged that times are tough for farmers but positive changes are on the way. "The president has to do what he has to do, but I'd like to see it done by harvest time, so we can get prices back to where they need to be," he added.

Earlier in the week, the Trump administration announced a trade agreement reached with Mexico. Talks are also ongoing with Canada as the White House looks to revamp the North American Free Trade Agreement. 

But with crop prices falling and even below the cost of production, many farmers, including Iowa farmer Time Bardole, remain concerned. "My son just started farming with us a year ago, and we did some expanding to make room for him. An operation like ours is going to be one of the first that's going to be a casualty if this continues on so long."

It's not just crop prices that are drawing concern amongst farmers. The tariffs on steel and aluminum imports into the US have added a further input cost for manufacturers of agricultural equipment. And that is putting yet more pressure on the farming industry as a whole. 

Farmer LeVerne Arndt is among those to feel that manufacturers will struggle to make sales this year. "I feel sorry for many of the people on this ground here. They probably thought they were going to sell more equipment, especially the larger pieces of equipment. It's going to hurt the farm economy and the economy around here."

The developments with Mexico and Canada give some hope to farmers. Davie Stephens, vice chairman of the American Soybean Association, hopes an agreement with China will soon follow. "China is a huge market to us. We've taken about 35 to 40 years to cultivate that relationship and get it worked out. And we don't want to lose that market as once we lose that market. There is a fear for me, will we get it back?"  

On the surface, business appears to be as usual at the Farm Progress Show. But given the uncertainty over tariffs, the reality is anything but usual.