The US soybean market has an "unusually thin" cushion to absorb supply shocks, such as a failed harvest this year, Oil World has said, in a note estimating that inventories have slumped by 40% in three months.

The oilseeds analysis group forecast US soybean stocks beginning this month at 35.63m tonnes (1.31bn bushels), cutting 670,000 tonnes from its previous estimate.

The figure would represent a fall of 28m tonnes, or more than 1bn bushels, since the start of December.

It would leave the US with little scope for meeting demand, which at a global level averages about 20m tonnes a month, should the pipeline from Argentina or Brazil rupture, or this year's US harvest struggle.

"The safety net to cushion any supply disruptions in South America or crop problems in the US this summer is thus unusually thin," the group said.

Lower still 

The data comes amid fears for the logistical problems of getting Brazilian production, currently in mid-harvest, to port and the threat of strike at the Argentine port of Rosario within the next fortnight by dockworkers sympathetic to the oil crush industry union, which is attempting to win better pay. 

Mr Good's figures are based on analysis of historical soybean use patterns, combined with actual export data and an extrapolation of soybean crush statistics.

For corn, his calculations foresee a March 1 inventory level of 178m tonnes (7.48bn bushels), up 7.5% year on year.

'Slow down pronouncedly'

Oil World added that US soybean crushers were likely to face a sharp slowdown in activity this month, thanks to slow domestic sales of soymeal and a switch by buyers to South America,

The comments echo those from the US Department of Agriculture, which has also forecast an imminent slide in US crushings, and reports that some processors have already begun mothballing capacity.

The USDA will on March 31 unveil inventory estimates for the beginning of the month, along with planting estimates for 2010 crops.