It is not just the US public finances which are approaching a "cliff".

The country's soybean exports are too, nearing what might be termed a physical cliff, in terms of exports, farm officials highlighted, in a report which flags a silver lining to oilseeds groups from the summer's drought.

The US Department of Agriculture - explaining a decision on Tuesday to leave its forecast for US soybean shipments in 2012-13 unchanged at 36.6m tonnes (1.354m bushels), well below the all-time high despite a record start to the season – said that the sharp drop-off in trade is nigh.

"The record pace," which saw the volume of soybean exports inspected by officials reach 648m bushels by December 6, "is unlikely to continue very long," the USDA said.

"It is likely that an uncommonly high percentage of soybean exports will be shipped in the first half of the marketing year.

"Exports should start slowing with a steep decline in new sales," the department said, in comments ahead of weekly US export sales data which came in at 1.3m tonnes - well ahead of market expectations and, indeed, the highest figure of 2012-13.

'Suddenly boosted prospects'

The expectations of the slump in trade reflect expectations that the onset of South American harvests early in 2013 will bring a fresh supply of soybeans onstream, replenishing global supplies depleted by the region's own poor harvest this year, besides that in the US.

Already, soybean processors in Argentina and Brazil "are slowing crush rates due to the scarcity of remaining soybean stocks there," the USDA said.

This dynamic was boosting the competitiveness of US exporters of soymeal and soyoil, the main products of soybean crushing, "at least for the next few months", and fuelling a rise in shipments to China which have in two months beaten their total for the whole of 2012-13.

"In November, unusually large export sales of soyoil have suddenly boosted US trade prospects for the commodity," said the department, which on Tuesday hiked by 280,000 tonnes, to 820,000 tonnes, its forecast for soyoil exports in 2012-13.

Record rate

The ability of US crushers to meet this demand is being helped by a positive factor stemming from the summer drought in the US, the worst since 1956, which cut yields to well below initial expectations.

The USDA, expanding on an upgrade of 210,000 tonnes to 8.30m tonnes in domestic soyoil production, said that the revision was down to "higher expected rates for both the crush and oil yield".

"Above-average oil content is often associated with soybean pods that fill out during an extended period of hot weather, like last summer," the department said.

"If realised, the soybean oil extraction rate forecast for 2012-13 would be at an all-time high."