Corn, soybean and wheat futures are down at least 15 percent since the end of August, helping to send the Standard & Poor's GSCI Agriculture Index to a 16 percent decline. The MSCI All-Country World Index of equities gained 4.7 percent during the period, touching a six-month high Feb. 3, while Treasuries returned 2.5 percent, a Bank of America Corp. index shows.

World food prices fell to a 14-month low in December, led by declines in grains, sugar and oilseeds, the UN's Food and Agriculture Organization said Jan. 12.

Monetary Fund

The USDA affirmed its forecast for moderating food costs last month. Prices will increase 2.5 percent to 3.5 percent in 2012, below last year's 3.7 percent gain, the agency said Jan. 25. The same day, the International Monetary Fund forecast a 14 percent drop in non-oil commodities this year, citing more supply.

Farmers in the Midwest, the main growing region, are less than two months away from planting seeds, and dry soils in some areas could limit output. The most widely-held option on December corn futures gives the holder the right to buy the grain at $7.

"It's been an abnormally warm winter," said Alan Tiemann, who is preparing to expand corn planting on his 2,000-acre farm in Seward, Nebraska, by 15 percent. "That may not relate to what's going to happen this summer, but it keeps you on the edge of your seat a little bit, wondering when the next moisture event is going to happen."

Corn averaged $6.79 in Chicago last year, the highest ever and twice the level of the previous decade, exchange data show. Soybeans averaged a record $13.21, 72 percent above the 10 previous years, while wheat's average of $7.235 was the second- highest ever and 57 percent more than the past decade.

Trading Commission

Money managers have been betting on lower wheat prices since September, U.S. Commodity Futures Trading Commission data show. They cut their bullish wagers on soybean and corn in two of the past three weeks.

Floods, drought and freezes last year prevented planting of the three crops on about 8.577 million acres, 28 percent more than in 2010, USDA data show. An additional 1.84 million acres that were planted failed to produce, more than double the amount a year earlier.

Crop insurers paid out a record $9.1 billion last year to cover the damage, and the bill may top $10 billion when all claims are settled, Overland Park, Kansas-based National Crop Insurance Services said Jan. 24.

A return to normal weather in 2012 would mean more production from last year's lost acres. The government also has reduced the amount of land it pays farmers to leave fallow by 4.7 percent, adding 1.47 million acres that weren't available in 2011, USDA data show.