Slumping prices and aggressive competition mean the US will import as much food in 2005 as it sells overseas, government figures say.
Old customers are becoming new rivals for US farmers
The Department of Agriculture report suggests exports will fall about 10% to about $56bn (£30bn), while imports grow 3.3% to reach the same level.
The US has been a net exporter of foodstuffs for almost half a century.
Canada is the only country thought likely to buy more US goods, with China showing the biggest fall in sales.
Cotton and soybeans are likely to be the biggest victims of a $1.5bn reduction in Chinese demand, the report's authors said.
Soybean sales the world over were predicted to fall almost 15%, as competition from Brazil and other countries hots up, while Russia - once a lucrative customer - is now a rival in the wheat trade.
And there could be more bad news yet to come for beef farmers.
Some 30 countries, including Japan, have banned US beef after several cases of BSE, or "mad cow disease", reducing exports by about $300m.
Tests on the most recent cow suspected to have been infected are due shortly.
The predictions from the Department of Agriculture could spur heightened calls from US farmers for more government assistance.
In 2002, the Bush administration upped farm subsidies by some $60bn, despite criticism from trading partners and potential problems with World Trade Organisation (WTO) negotiations.