WASHINGTON — US farmers will plant the largest area to the three principal field crops — wheat, corn and soybean — since 2016, Seth Meyer, chief economist of the US Department of Agriculture, said in an address before the 2021 Agricultural Outlook Forum on Feb. 18. Plantings for the three crops combined were forecast at 227 million acres.

Mr. Meyer said sharply higher crop prices since the fall on tightening global supplies and strong international demand, particularly from China, will encourage the expansion in crop area.

The chief economist pointed to the large number of acres in the United States that went unplanted last spring because of adverse weather.

“With a return to more normal planting weather, we expect a good portion of those acres that were unplanted last year to be planted to corn and soybeans in 2021,” Mr. Meyer said. “The current stocks-to-use ratios for corn and soybeans, the lowest since 2013-14, and strong international demand for both commodities, suggest better returns for corn and soybeans relative to wheat, cotton, and many other crops, with strong overall incentive to plant.”

Mr. Meyer added, “Current new crop futures prices and contract bids for fall delivery signal strong acreage increases, particularly for soybeans, for which acreage is expected to expand 6.9 million acres to 90 million.”

Corn area, also because of higher prices, was expected to increase 1 million acres from 2020 to 92 million acres.

“The combined two-crop acreage is expected to reach a record 182 million acres, compared with the previous record in 2017 of 180.3 million acres,” Mr. Meyer observed.

“Given continued strong international demand and tight stocks, we projected that soybean prices will remain elevated,” Mr. Meyer said. “The soybean price will also be supported by strong domestic demand and growth in US renewable fuel capacity.

“In contrast, corn prices are expected to decline slightly with larger corn acres and an expected return to trend yields leading to slightly higher ending stocks with strong global demand moderating the price decline on what is expected to be a large crop under normal weather conditions.”

Mr. Meyer said planted area for winter wheat was estimated at 32 million acres, up 5% from 2020 and the first increase in winter wheat acreage since 2013.

“However, higher expected net returns for corn and soybeans in the northern Plains are anticipated to reduced combined spring and durum wheat plantings in 2021,” Mr. Meyer noted.

“Total wheat area for 2021 is projected at 45 million acres, up 651,000 acres from the previous year but still below the five-year average,” Mr. Meyer said. “Wheat prices are projected to rise as lower carry-in stocks and supplies lead to tighter ending stocks.”