WASHINGTON — U.S. production of biofuels will continue to rise in the next 10 years but at a much slower pace than was the case in the past decade, according to long-term forecasts issued Feb. 11 by the U.S. Department of Agriculture in its U.S.D.A. Agricultural Projections to 2022.

The two principal biofuels produced in the United States are ethanol, which still is almost entirely corn based, and biodiesel, mostly derived from soybean oil, although other oils as well as meat fats have played prominent roles as feed stocks.

In 2004-05, corn used in the production of ethanol totaled 1,323,210,000 bus, which equated to 11% of the 2004 corn outturn of 11,805,581,000 bus. By 2011-12, corn used in the production of ethanol reached 5,011,030,000 bus, which equated to 40% of the 2011 corn outturn of 12,359,612,000 bus.

The amount of corn used in the production of ethanol was forecast to drop to 4,500,000 bus in 2012-13, or 42% of the drought-reduced 2012 corn outturn of 10,725,000 bus. Corn use for ethanol production was forecast to begin to increase steadily in subsequent years but not surpass the 2011-12 level until 2020-21. Corn use for ethanol was forecast at 5,375,000,000 bus in 2022-23, the last year in the projection period.

The U.S.D.A. said in commentary accompanying its corn supply-and-demand forecasts through 2022-23, “Projected increases in corn-based ethanol over the next 10 years are much smaller than occurred in 2005-2010. This projection reflects declining overall gasoline consumption in the United States (which is mostly a 10% ethanol blend, E10), infrastructural and other constraints on growth in the E15 (15% ethanol blend) market, and the small size of the E85 (85% ethanol blend) market. Nonetheless, a strong presence for ethanol in the sector continues, with about 35% of total corn use expected to go to ethanol production during the projection period.”

The use of soybean oil in the production of methyl esters (biodiesel) in the United States was estimated at 4,900 million lbs in 2011-12 and forecast at 4,900 million lbs in 2012-13 and at 5,000 million lbs in 2013-14. Soybean oil use in the production of biodiesel was forecast to rise steadily each year in the rest of the projection period reaching 6,300 million lbs in 2022-23.

“Soybean oil used to produce methyl esters (biodiesel) in the United States grows to 6.3 billion lbs by the end of the projection period, representing about 29% of total use of U.S. soybean oil and supporting the production of more than 800 million gallons of biodiesel,” the U.S.D.A. said. “This growth is spurred by the mandate of 1.28 billion gallons of biomass-based diesel use starting in 2013, and by demand for biodiesel to meet a portion of the Renewable Fuel Standard’s advanced biofuel mandate. Corn oil co-products form ethanol plants (including corn oil extracted from distillers grains), other first-use vegetable oils, animal fats and recycled vegetable oils are also used as feed stocks to produce biodiesel.”