Wisconsin corn and soybean yields fall behind national average

Thanks to a slow start to the planting season and a wet harvest, Wisconsin producers had mixed results in corn and soybean yields in 2018.

The results are published in the USDA’s National Agricultural Statistics Service County Yield Estimates, which include county average crop yields per harvested acre for corn and soybeans.

Corn Yields

Nationally, the average corn yield in 2018 was 176.4 bu/acre, down slightly from the prior year. At the county-level, corn yields ranged from less than 100 bu/acre in portions of the Southeast and the western Corn Belt to greater than 200 bu/acre across many portions of the Corn Belt, according to American Farm Bureau Economist John Newton.

Wisconsin trailed behind the national average, reporting an average statewide corn yield of 172 bu/acre. In reporting counties in the Badger state, the South Central District recorded the highest corn for grain production with 139 million bushels. Dane County was the largest corn producing county with 30.2 million bushels. Grant, Rock, Dodge and Lafayette rounded out the top five.

Grant led all counties in Wisconsin with a county average yield of 202.7 bu/acre. Lafayette (197.3), Walworth (194.1), Dodge (191.6), and Iowa (190.4) Counties rounded out the top five.

Eleven counties exceeded the 180 bu/acre yield mark—Pierce (189.2); Dane (188.9); Rock (184.2); Fond du Lac, (183.8) and Waukesha (182). Yields are derived from production divided by area harvested. Only published estimates were considered in rankings of districts and counties.

Planted corn acres statewide remained unchanged from 2017 to 2018. While farmers harvested 240,000 additional acres in 2018, the yield average fell by 2/bu/acre. Meanwhile, statewide production grew by 35.4 million bushels in 2018 over the previous year.

Only published estimates were considered in rankings of districts and counties. Twenty-nine percent of the counties did not report results.

Newton said that more than half of the corn-producing counties in the U.S. had lower corn yields in 2018 relative to 2017. In total, 651 counties experienced poorer crop yields in 2018 compared to 2017, with yield declines ranging from as little as 1 percent to greater than 50 percent. Yield declines were the sharpest in portions of the Southeast following two Category 4 hurricanes and in the western Corn Belt following excessive precipitation during harvest season.

While many counties experienced lower corn yields in 2018, across the eastern Corn Belt in Indiana, Illinois and western Ohio, as well as in South Dakota, crop yields were higher compared to prior-year levels. Many counties in these states saw yield increases of more than 10 percent, Newton pointed out.

Corn silage

Wisconsin producers in the East Central District chopped 4.32 million tons of corn silage in 2018, representing 32 percent of the State total, according to estimates released by NASS.

The Southwest District produced 1.57 million tons of silage, accounting for 12 percent of the State total. Fond du Lac County was the top corn silage county in Wisconsin with 1.11 million tons of corn silage produced. Manitowoc, Brown, Kewaunee, and Marathon rounded out the top five.

Polk County had the highest average yield, at 24.0 tons/acre. Columbia, Fond du Lac, and Richland Counties had the next highest yields at 23.0 tons/acre. Pepin and Washington Counties rounded out the top 6 list with a yield of 22.0.

Ten counties had average yields of 20.0 or more tons per acre. Yields are derived from production divided by area harvested.

Corn acres for silage were down statewide in 2018, with farmers harvesting just 670,000 acres, down 210,000 acres in 2017. Total production estimate also fell statewide from 16.7 million tons in 2017 to 13.4 million tons in 2018, a decrease of 3.3 million tons. Despite fewer acres harvested, average yields increased to 20.0 tons/acre, up 1 ton/acre than 2017.

Soybean Yield

Last year, the U.S. average soybean yield was 51.6 bu/acre – the second highest of all time – and up nearly 5 percent from the prior year. According to the NASS report, Wisconsin's average soybean yield was 49 bu/acre.

At the county-level, reported Wisconsin soybean yields ranged from 31.1 bu/acre in Sawyer County in northwest Wisconsin to 64.6 bu/acre in Grant County in southwest Wisconsin.

In 2018, farmers in Rock County led the State in soybean production with 5.23 million bushels. Grant (5.04 million), Dane (4.81 million), Dodge (4.18 million), and Lafayette (3.93 million) rounded out the top five highest production counties.

Four districts had yields averaging over 50 bu/acre, led by the Southwest District, where the average soybean yield was 56.2 bu/acre, followed by the South Central District (55.4), Southeast District (52.3) and the East Central District (50.2).  The North Central District had the lowest yield, averaging 39.7 bu/acre.

Statewide, 13 counties averaged over 50 bushels per acre, led by Grant County, where soybeans averaged 64.6 bu/acre. Lafayette (64.0), Dane (56.3), Rock (55.5), and Manitowoc (52.7) rounded out the top 5 yields.

Last year, Wisconsin farmers planted an estimated 2.2 million acres of soybeans, up just 50,000 acres from the previous year. The state averaged around 49 bu/acre, an increase of 1.5 bu/acre. Wisconsin produced 105.8 bushels of soybeans last year, up 4.2 million bushels in the previous year.

Nationally, many counties reported soybean yields of less than 40 bu/acre in portions of the Southeast and Upper Midwest to greater than 60 bushels per acre from Nebraska, through the Corn Belt and into Western Ohio.

Soybean yields per harvested acre were the lowest in Onslow County, North Carolina, at 18.4 bushels per acre and were the highest in Sangamon County, Illinois, at 82.3 bushels per acre.

Weather and crop insurance

Carried by very strong yield improvements in portions of Illinois, Indiana, eastern Iowa, western Ohio and other areas, Newton said U.S. average corn and soybean yields in 2018 were above trend projections and at or near record highs.

"However, prolonged and excessive rainfall during the harvest season resulted in lower corn and soybean yields in many counties," Newton said in a news release. "In portions of western Iowa, counties along the southern Mississippi River and other parts of the Southeast, crop yields fell by more than 10 percent."

Farmers who experienced a poorer yield or a crop loss in 2018 could potentially receive benefits from crop insurance’s yield or revenue protection policies, he said.

"The lower crop yields will also factor into Agriculture Risk Coverage program payments as the actual revenue in 2018 could be lower than the benchmark guarantee. Agriculture Risk Coverage is based on the crop yield per planted acre and will help to cover revenue declines experienced due to adverse weather and unharvested acreage.