WASHINGTON — U.S. farmers intend to boost 2015 soybean planted area by 1% and to a record high but reduce corn plantings by 2% and all wheat acreage by 3% from 2014, the U.S. Department of Agriculture said in its March 31 Prospective Plantings report.

Growers intend to plant a record high 84,635,000 acres of soybeans in 2015, up 1% from 83,701,000 acres in 2014 but 1% below the average trade estimate of 85.87 million acres.

“Compared with last year, planted acreage intentions are up or unchanged in 21 of the 31 major producing states,” the U.S.D.A. said. “Increases of 200,000 acres or more are anticipated in Arkansas, Iowa and Ohio. The largest declines are expected in Kansas and Nebraska.”

Farmers indicated they intend to plant 89,199,000 acres of corn in 2015, down 2% from 90,597,000 acres in 2014 and down 6% from 2013 but above average trade expectations of 88.68 million acres.

“If realized, this will be the lowest planted acreage in the United States since 2010,” the U.S.D.A. said. “The reduction in planted acres is mainly due to the expectation of lower prices and returns in 2015.”

Planted area for corn is expected to be down across most of the Corn Belt except for Minnesota and Wisconsin, which are expecting increases, and Nebraska, which is unchanged.

Planted all wheat area for harvest in 2015 was forecast at 55,367,000 acres, down 3% from 56,822,000 acres seeded for harvest in 2014, the U.S.D.A. said.

Winter wheat area seeded in 2014 for harvest in 2015 was estimated at 40,751,000 acres, down 4% from 42,399,000 acres last year but up slightly from the January seedings estimate of 40,452,000 acres. The winter wheat estimate includes 29.6 million acres of hard red, 7.75 million acres of soft red and 3.43 million acres of white wheat.

Farmers intend to plant 1,647,000 acres of durum in 2015, up 18% from 1,398,000 acres last year, and 12,969,000 acres of spring wheat other than durum, down slightly from 13,025,000 acres in 2014. The spring wheat area includes 12.1 million acres of hard red spring wheat.

The U.S.D.A. all wheat planting number was below the average of trade expectations of 55.61 million acres, with winter wheat above the average trade estimate of 40.58 million acres, the other spring wheat number below the average of 13.24 million acres and durum also below the average of 1.73 million acres.

Concerning winter wheat planted area, the U.S.D.A. said, “States with notable acreage increases from the previous estimate were Missouri, Montana and Oklahoma, while notable decreases occurred in Nebraska and North Dakota. If realized, a new record low would be set in Utah.”

Of spring wheat other than durum, the U.S.D.A. said, “Compared with last year, acreage increases are expected in the Pacific Northwest, as well as Minnesota and North Dakota. Decreases are expected in Montana, Nevada and Utah. If realized, planted acres will be record low in Utah.”

And for durum, the U.S.D.A. said, “Planted acreage is expected to increase in all states except Idaho (where a record low is expected).”

Area planted to all cotton was forecast at 9,549,000 acres, down 13% from 2014 and the lowest since 2009.

Intended area planted to rice in 2015 was estimated at 2,915,000 acres, down 1% from 2,939,000 acres in 2014.

Planting intentions for oats totaled 2,931,000 acres, up 8% from 2,723,000 acres in 2014 but still the fourth lowest on record if realized, the U.S.D.A. said.

Area planted to barley was projected at 3,258,000 acres, up 10% from 2,975,000 acres last year but also the fourth lowest on record.

Growers intend to plant 7,900,000 acres of grain sorghum, up 11% from 7,138,000 acres in 2014.

Peanut planted area was expected to total 1,481,000 acres, up 9% from 1,354,000 acres in 2014.

Sugar beet planting intentions were 1,182,100 acres, up 2% from 1,161,600 acres planted in 2014.

The plantings report, along with the U.S.D.A.’s Grain Stocks report also released on March 31, resulted in corn futures prices falling about 12c a bu and wheat futures prices tumbling as much as 16c a bu shortly after the reports were released. Soybean futures were trading about 6c a bu higher.