WASHINGTON — U.S. farmers intend to boost 2013 corn planted area slightly and all wheat acreage by 1% but trim soybean area from 2012, the U.S. Department of Agriculture said in its March 28 annual Prospective Plantings report.

Planted wheat area for harvest in 2013 was forecast at 56,440,000 acres, up 1% from 55,736,000 acres seeded last year, the U.S.D.A. said.

Winter wheat area seeded in 2012 for harvest in 2013 was estimated at 41,988,000 acres, up 2% from 41,324,000 acres last year and up slightly from the January estimate of 41,820,000 acres. The winter wheat estimate includes 28.9 million acres of hard red, 9.67 million acres of soft red and 3.39 million acres of white wheat.

Farmers intend to plant 1,751,000 acres of durum in 2013, down 18% from 2,123,000 acres last year, and 12,701,000 acres of spring wheat other than durum, up 3% from 12,289,000 acres in 2012. The spring wheat area includes 12.1 million acres of hard red spring wheat.

The U.S.D.A. all wheat planting number was near the average of trade expectations of 56.4 million acres, with the other spring wheat number above the average trade estimate of 12.5 million acres, durum well below the trade average of 2.1 million acres and winter wheat above the trade forecast of 41.8 million acres. The report, along with quarterly Grain Stocks data also released March 28, was called bearish for wheat futures prices, which along with corn and soy complex futures were trading sharply lower after the reports.

“Acreage increases from the previous report were mainly in the soft red winter growing states,” the U.S.D.A. said. “Winter wheat conditions improved over the winter in much of the hard red winter growing area.

“Planted (durum) acreage is expected to be down in all states except South Dakota. If realized, planted acres will be record low in Idaho.”

Farmers indicated they intend to plant 97,282,000 acres of corn in 2013, up slightly from 97,155,000 acres in 2012 and near trade expectations that averaged 97.3 million acres.

“If realized, this will represent the highest planted acreage in the United States since 1936 when an estimated 102 million acres were planted,” the U.S.D.A. said. “Most states in the Corn Belt, which experienced severe drought in 2012, expect slightly less planted acreage. Expected returns for corn are again historically high going into 2013.”

Growers intend to plant 77,126,000 acres of soybeans in 2013, down slightly from 77,198,000 acres in 2012 and below the average trade estimate of 78.5 million acres.

“Compared with 2012, planted area is down across the Great Plains with the exception of North Dakota,” the U.S.D.A. said. “Nebraska and Minnesota are expecting the largest declines compared with last year, while Illinois and North Dakota are expecting the largest increases.”

Area planted to all cotton was forecast at 10,026,000 acres, down 19% from 2012, the U.S.D.A. said, with area in Arkansas, Louisiana, Mississippi, New Mexico and Oklahoma record low if realized.

Intended area planted to rice in 2013 was estimated at 2,611,000 acres, down 3% from 2,699,000 acres in 2012.

Planting intentions for oats totaled 2,901,000 acres, up 5% from 2,760,000 acres in 2012 but still the third lowest on record if realized, the U.S.D.A. said.

Area planted to barley was projected at 3,634,000 acres, down slightly from 3,637,000 acres last year.

Growers intend to plant 7,620,000 acres of grain sorghum, up 22% from 6,244,000 acres in 2012.

Peanut planted area was expected to total 1,191,000 acres, down 27% from 1,638,000 acres in 2012.

Sugar beet planting intentions were 1,211,100 acres, down 2% from 1,230,100 acres planted in 2012.