WASHINGTON, June 30 (Reuters) - U.S. farmers seeded a record amount of soybeans this spring, the government said on Friday, amid hopes that strong export demand will soak up much of the harvest this fall despite bumper crops in Brazil and Argentina that have swelled global stocks.
All-wheat plantings fell to a record low of 45.657 million acres, with ample global stocks and weak export prospects pushing U.S. farmers away from that crop.
Corn plantings rose unexpectedly from the U.S. Agriculture Department's March estimate.
Spring wheat plantings dropped to a 45-year low. Prices for spring wheat have surged to their highest levels since 2014 this week as drought conditions in the northern U.S. Plains threaten crop yields, stoking concerns about a supply crunch for high-protein wheat in the coming months.
Supplies for all three commodities remained robust, with stocks of both corn and soybeans as of June 1 the third biggest ever for the period. Wheat stocks as of June 1 were the largest in 29 years.
USDA said farmers planted 90.886 million acres of corn, up 890,000 acres from the government's March forecast. Analysts had been expecting corn plantings of 89.903 million acres, according to the average of analysts estimates in a Reuters poll.
Soybean plantings came in at 89.513 million acres compared to analysts' estimates of 89.750 million. In March, USDA had forecast soy plantings of 89.482 million acres.
USDA pegged spring wheat acreage at 10.899 million acres, down from its March estimate of 11.308 million acres and below the low end of analysts expectations that ranged from 10.990 million to 11.589 million. In 1972, the last time spring wheat plantings were below the 2017 total, farmers planted 10.138 million acres.
On the supply front, corn stocks as of June 1 were 5.225 million bushels, up from 4.711 million bushels a year earlier and the most since 1987.
Soybean stocks as of June 1 were 963 million bushels, up from 872 million bushels a year earlier. The June 1 soy stocks reading was the biggest in 10 years.
Wheat stocks rose to 1.184 billion bushels from 976 million bushels a year earlier.
The average of analysts' stocks estimates was 1.137 billion bushels for wheat, 5.123 billion bushels for corn and 983 million bushels for soybeans.
(Reporting by Mark Weinraub; Editing by Paul Simao)