U.S. farmers, driven by strong crop prices, will be planting nearly 96 million acres of corn this year, topping market expectations and a 4% increase over last year's acreage, the U.S. Department of Agriculture said Friday.

A shift over to corn and away from soybeans as farmers try to predict where the best returns will come from is behind much of the increase, the USDA said.

The new forecast, released in the annual survey-based Prospective Plantings report, calls for the most acreage of corn since 1937 when farmers planted about 97 million acres.

"Planted acreage is expected to be up in most states compared to last year due to expectations of better net returns in 2012 compared to other commodities," the USDA said.

Farmers in Idaho, Iowa, Minnesota, North Dakota and South Dakota are forecast to plant record-breaking amounts of corn this year, according to the report.

Soybean acreage is expected to decline in the U.S. this year to about 74 million acres, a 1% drop from last year and 5% less than 2010, the USDA said. The level of soybean planting either remained the same or dropped off from last year throughout the Corn Belt and Great Plains.

"Compared with last year planted acreage intentions are down in many areas as some acreage is expected to shift to corn," the USDA said. "Additionally, soybean acreage intentions in Kansas, Oklahoma and Texas are down from 2011 due to drought conditions that have continued from last year into early March."

Meanwhile, there is less corn and more soybeans in storage now.

Stockpiles from the previous year's corn crop are lower now, the USDA said. Corn stocks, stored either on- or off-farm, total 6.01 billion bushels, an 8% decrease from about this time a year ago. And there are 1.37 billion bushels of soybeans in storage around the country now, a 10% increase from last year.

And there are 1.2 billion bushels of wheat stocks in storage now, 16% less than a year ago.

-By Bill Tomson, Dow Jones Newswires; 202-646-0088; bill.tomson@dowjones.com

(END) Dow Jones Newswires

March 30, 2012 08:31 ET (12:31 GMT)