Three-week delays in shipping soybeans from Brazilian ports are shifting importers to the U.S. for coverage of near term supply needs.

Soybean supplies stored at export terminals and elevators at Louisiana Gulf ports dropped by 1.479 million bushels, or 34%, in the week ended Tuesday, according to data released by U.S. Department of Agriculture.

The drop in stocks at the Gulf is a signal that end users are tapping into stored soybean supplies at a fast pace, said Karl Setzer, analyst with MaxYield Cooperative in West Bend, Iowa.

Farmer sales of U.S. soybeans up until this week were not keeping up with relative needs of the spot market, pushing basis levels to record levels for this time of year.

Basis is the difference between cash and futures prices.

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Farmers unhappy with the lower prices, shut the doors to their storage facilities, unwilling to market supplies until prices rallied.

U.S. exporters and domestic processors remain in a price war for available U.S. supplies.

"The drawdown of Gulf inventories is the result of a strong export pace and domestic crushers stopping many beans from making it to River terminals for shipment to the Gulf," Setzer said.

Despite an incredible amount of supplies entering the cash supply chain in the past three days on rallying soybean futures prices, domestic crushers are still pushing basis levels to secure inventories, Setzer said. "End users know the flush of fresh farmer sales is a short term event, and want to lock in as much inventory before that selling runs dry," Setzer added.

Farmer selling historically dries up once the planting season begins, as producers working in their fields have little time for shipping supplies to grain elevators. End users particularly domestic crushers want to book as much supply as they can before being forced to pay higher prices from commercial elevators once farmers shift attention to planting needs.

Exporters continue to step up their push for inventories, as world importers shift attention back to the U.S. amid the threat of smaller South American crops after heat and dryness cut yield potential.

Increased export demand has resulted in Louisiana Gulf basis bids holding firm in the face of rallying futures in an attempt to lure supplies to export locations to replenish declining inventories.

Cash prices rose 2.5% for soybeans at the U.S. Gulf since last week compared to a 2.7% rise in futures during the same period, according to U.S. Department of Agriculture data.

Export terminals are paying upwards of $13.89 a bushel for soybeans, 78 cents above the March CBOT soybean futures contract.

"Cash prices trading at significant premiums to futures, indicate commercial firms are still having a tough time sourcing available supplies," said Dave Marshall, independent marketing adviser in southern Illinois.