DES MOINES, Iowa (AP) — China's announcement Monday of higher tariffs on $60 billion of American exports — retaliation for President Donald Trump's latest penalties on Chinese goods — hit particularly hard in the farm belt. China's vast consumer market has been a vital source of revenue for American farmers.

Since December, when U.S. and China negotiators called a truce to tariffs and began signaling that an agreement might be reached, soybean farmers had been holding out hope that sales to China would resume, said Todd Hultman, an Omaha-based grain market analyst with agriculture market data provider DTN. In the meantime, the farmers had been storing a record stockpile of nearly 1 billion bushels.

The latest news of a new round of tariffs, with no agreement in sight, spooked the financial markets and some farmers who had been tentatively optimistic.

"This is hitting the market at a very emotionally distressful time," Hultman said. "The rug of hope was pulled out from under us and especially with the announcement this morning that China is going to retaliate with higher tariffs of their own."

In a statement Monday, the American Soybean Association reacted with frustration edged with anxiety.

"The sentiment out in farm country is getting grimmer by the day," said John Heisdorffer, a soybean farmer in Keota, Iowa, who is chairman of the ASA. "Our patience is waning, our finances are suffering and the stress from months of living with the consequences of these tariffs is mounting."

A slowdown in soybean sales, and the huge stockpiles that result, has a ripple effect. Farmers in many parts of the corn belt have suffered from a wet and cooler spring, which has prevented them from planting corn. Typically when it becomes too late to plant corn, farmers will instead plant soybeans, which can grow later into the fall before harvest is required. Yet now, planting soybeans with the overabundance already in bins and scant hope for sales to one of the biggest buyers in China, could raise the risk of a financial disaster.