At the Kimberley family farm in rural Iowa the winter frost has lifted and the next few weeks will bring soybean planting season.
"One in every three rows of beans goes to China," said Grant Kimberley, watching a combine harvester spraying fertilizer across a vast field.
But Mr Kimberley, 42, whose ancestors have tilled the soil here since the 1860s, didn't look overly confident those exports would continue.
A potentially devastating trade war looms and US soybeans headed for China could face a 25 per cent tariff. The proposed tariff hangs like a sword of Damocles over Iowa, a state bigger than England known as the "breadbasket of America".
Forty per cent of China's soybeans, $14 billion worth a year, come from the US, and much of that comes from Iowa. The state is now awash with predictions of impending economic doom, and growing anger at Donald Trump for triggering the crisis in the first place by putting tariffs on Chinese steel.
Nowhere would a prolonged trade war bring more disappointment than at the 4,000-acre Kimberley farm, which has in some sense become a focal point for Sino-US trade relations.
In 2012 China's President Xi Jinping, who was vice president at the time, visited the Kimberleys - Grant, his father Rick, and mother Martha - on a tour of America. He sat in their living room and examined a jar of soybeans on the coffee table, explored the shiny metal storage facilities, and drove a giant computerised tractor.
He liked the place so much that a replica "friendship farm" - including a copy of the Kimberleys’ house - is being built in China's Hebei province. Rick Kimberley, 67, was recently in Hebei for the groundbreaking ceremony.
"President Xi sat on that couch just there and hung out," said Grant Kimberley. "I can tell you he’s not your old-school stoic Chinese leader. We talked about the importance of trade between our countries, biotechnology, seed technology. He knows agriculture."
Mr Xi's connection to Iowa goes back to 1985 when, as a party official, he spent two weeks in the state researching farming and lodging with an Iowan family.
That was his first visit to America and, according to those who have spoken to him, he retains a deep fondness for the state. Sadly for Iowa, however, that also means Mr Xi knows well both its economic and political importance.
In addition to being an agricultural powerhouse the state holds a special place in the electoral calendar, voting first in primary elections. In the 2016 general election Mr Trump won with 51 per cent of the vote, largely because farmers rallied behind him.
"The Chinese are very politically astute. President Xi has been to Iowa, he knows the place," said Mr Kimberley. "They know the Mid West is important to Trump. They're communist but they know Democratic political problems. And they're smart businessmen, they've been doing it for 2,000 years." He added: "We had been hoping agriculture would be left out of all this, that it wouldn’t be used as a weapon.
“I don't believe he (Mr Xi) does want tariffs, but he will protect his country.”
If a trade war lasted until 2020, sending many Iowan farmers out of business, they would make their displeasure known at the ballot box. Sooner, they could abandon Republicans in the mid-term congressional elections in November.
The Des Moines Register, the biggest newspaper in Iowa, has been in the vanguard of the outrage, accusing Mr Trump of "playing politics with Iowa's economy" and having "no loyalty" to a state that backed him.
The Quad City Times said Iowa had been "conned". Dave Struthers, a soybean and pig farmer, said the president was making a mistake. He added: "I think it’s going to hurt him, I really do.”
Bill Shipley, president of the Iowa Soybean Association, publicly called on Mr Trump to visit his farm and "meet the people who help create one of America’s most valuable exports".
He said: "Trade wars involving food are a lose-lose." While the rest of the world 's attention was focused on Syria, Mr Trump and his agriculture secretary Sonny Purdue spent Thursday conducting a rearguard action at the White House, huddling with Republican politicians from farming states.
Iowa's Republican governor Kim Reynolds told him tariffs would be "devastating". Mr Trump said he "loved farmers" but they would have to take a hit as he tackled the overall $375 billion US trade deficit with China.
"We'll make it up to them," he promised. The stand-off with China began in earnest a month go when Mr Trump announced a 25 per cent tariff on steel and 10 per cent on aluminium.
He then followed up with another $50 billion worth of proposed tariffs on Chinese goods. China responded in kind, proposing $50 billion on over 100 US goods, including three major imports - soybeans, planes and cars. Studies have suggested the proposed tariffs would reduce US soybean exports to China by 71 per cent.
The gap would be filled by South American producers, and Iowa farmers are already monitoring weather forecasts in Brazil and Argentina.
Meanwhile, Iowa's pig farmers are being hit by a Chinese tariff that has already come into effect. Iowa has three times as many pigs as any other US state. There are 20 million, compared to only three million people. The price of an average-sized pig is down from $170 two weeks ago to $125 now.
Farmers who supported Mr Trump knew he had campaigned on protectionist manufacturing policies. They had hoped agriculture would be spared in any trade war.
But Chad Hart, an a agriculture economist at Iowa State University, said China had deliberately targeted a state that was the "world's grocery store," and a place politically valuable to Mr Trump.
"I'm sure that's a bit of the calculus behind it," he said. "I think at the moment folks here are waiting to see how the Trump administration responds."
In China they are also already feeling the effects of the nascent trade war.
Sun Chao, chief manager of Tianjiao Group, an animal feed supplier in Tianjin, said his company buys bean pulp imported from the US, and sells it on as pig feed to local farmers.
He said: “Prices of bean pulp have already gone up at least 25 per cent, which makes our prices also higher for pig farmers.”
Gary Dvorchak, an Iowan businessman who now lives in Beijing, said: “I think this has made the Chinese sit up straight and make them think that this is not like other US administrations.”
How soybeans sow discontent in trade war
On his 1985 formative visit Mr Xi lodged in Mr Dvorchak’s Iowa bedroom. Mr Dvorchak was away at college at the time. He said Mr Xi’s fondness for Iowa may “mitigate the amount of pain he would want to cause” but the Chinese president would “do what he has to do”.
Mr Dvorchak added: “I have a lot of friends in Iowa, and a lot are soybean farmers. I think they’re going to have to carry the water for their country, I don’t think there is any other way around it.
“But within a year there will be a deal which opens some markets for us in China, and in general the terms of trade are better off.”
As he prepared for planting Mr Kimberley was also determined to remain optimistic. He was sticking with planting soybeans rather than changing to another crop like corn, as some Iowa farmers are considering. And he was confident Mr Xi and Mr Trump could reach a deal.
"I think President Xi understands how important trade is to his country,” he said. “Long term, it's in their best interests to resolve this as well."
He added: "After Brexit I hope we get a free trade agreement with you guys in the UK. That might help a bit.”