your largest soybean export customer is having negotiations with your government. >> reporter: and president trump's take no prisoner negotiation style is worrying the rural constituency that helped put him in the white house. >> i have some concerns with the president. >> reporter: china is threatening to put a 25% tariff on all soybeans. the result of all iowa soybean farmers has been stomach churning for a crop that hasn't even been planted yet. >> i grow 125 bush he wiels. a year. that's $50,000, so that's a big deal. >> in the united states, one of three rows you see driving down the road will end up in china. >> reporter: he's a sixth generation farmer in his family, and like many, he's hoping the tariff threats don't become a reality. >> i want to encourage both governments to continue the