GRAINS-Corn, soybeans climb on supply worries after USDA report

* March 1 corn supplies miss analysts' expectations

* USDA sees U.S. corn acres down sharply from 2013

* Record U.S. soybean plantings expected

(Updates with USDA data, analyst comments) CHICAGO, March 31 (Reuters) - U.S. corn futures on Monday climbed above $5 per bushel for the first time since September after a highly anticipated U.S. crop report revealed that inventories were smaller than expected on March 1. The market gained further support from U.S. Department of Agriculture data projecting that U.S. farmers will plant fewer acres of corn this spring than analysts had expected. The reduced plantings outlook combined with concerns about tightening supplies to fuel fears of potential production risks during the upcoming growing season. Traders had been expecting supplies to be more comfortable this year after a massive U.S. harvest in 2013. "Corn acres were a huge drop from a year ago," said Karl Setzer, grain solutions team leader for MaxYield Cooperative. "I just can't see where those corn acres are going to be lost." Soybean futures rallied on concerns about tight supplies as well, with March 1 inventories below levels from a year earlier. Chicago Board of Trade May corn was up 7 cents, or 1.4 percent, at $4.99 a bushel by 12:25 p.m. CDT (1725 GMT). May soybeans surged 21-1/2 cents, or 1.5 percent, to $14.58 per bushel. The USDA, in a quarterly grain stocks report, said U.S. soybean stocks on March 1 were 992 million bushels, above analysts' expectations for 989 million bushels. However, stocks were down from 998 million a year earlier. Despite a large U.S. soy harvest last year, strong demand for U.S. crushing and for exports has kept supplies low. "The USDA report today didn't solve the problem for tight 2013/14 stocks," said Mike Zuzolo, president of Global Commodity Analytics. "I think the trade is taking it upon themselves to take prices up against that $14.60 resistance to encourage imports. We don't have conclusive evidence that we have rationed enough demand yet, after today's stocks report." U.S. corn stockpiles were 7.006 billion bushels as of March 1, below analysts' expectations for 7.099 billion bushels. Wheat stocks were 1.056 billion bushels, above analysts' estimates for 1.042 billion. CBOT May wheat was down 3-3/4 cents, or 0.5 percent, at $6.91-3/4 a bushel. Following the release of Monday's stocks data, the USDA will likely lower its 2013/14 U.S. corn carryout estimate by 50 million bushels in a monthly supply/demand report on April 9, said Terry Reilly, senior commodity analyst for Futures International. The soybean carryout will likely drop by 10 to 15 million bushels in the April report, he projected.

MASSIVE SOY PLANTINGS SEEN The USDA on Monday projected soybean plantings at a record 81.5 million acres, up 6 percent from last year, suggesting a bin-busting harvest above 3.6 billion bushels. Analysts had expected plantings of 81.1 million. Expectations for large plantings pressured new-crop soybean futures while nearby prices jumped. November soybeans were down 5-1/2 cents at $11.85 a bushel. U.S. farmers will plant the smallest amount of corn since 2010 and cut back on other feed grains as they switch into soybeans and other oilseeds this spring, according to the USDA.

The government pegged corn plantings at 91.7 million acres, down from 95.4 million last year and below analysts' expectations for 92.7 million.

Prices at 12:19 p.m. CDT (1719 GMT)

LAST NET PCT YTD CHG CHG CHG CBOT corn 498.75 6.75 1.4% 18.2% CBOT soy 1456.75 20.25 1.4% 11.0% CBOT meal 476.50 8.10 1.7% 8.9% CBOT soyoil 40.42 -0.06 -0.2% 4.1% CBOT wheat 691.00 -4.50 -0.7% 14.2% CBOT rice 1555.50 4.50 0.3% 0.3% EU wheat 207.50 -2.25 -1.1% -0.7% US crude 101.43 -0.24 -0.2% 3.1% Dow Jones 16,467 144 0.9% -0.7% Gold 1285.25 -8.25 -0.6% 6.6% Euro/dollar 1.3772 0.0020 0.1% 0.9% Dollar Index 80.0770 -0.0990 -0.1% 0.1% Baltic Freight 1362 -11 -0.8% -40.2%

(Additional reporting by Julie Ingwersen in Chicago, Manolo Serapio Jr in Singapore and Sybille de La Hamaide in Paris; editing by Joseph Radford, Richard Pullin, David Evans and Matthew Lewis)